GNSS antenna systems, elements and methods

Abstract

Global Navigation Satellite System (GNSS) antenna design needs to take into account a range of characteristics such as the ability to track satellites at low elevation angles, phase center variations (PCV), antenna efficiency and impedance, axial ratio and up-down ratio (UDR), antenna bandwidth, etc. while also providing a light weight, compact and robust form factor. This is particularly important for rover applications where the satellite being visited can be at low elevation angles, and where prior art GNSS antenna performance is poor. To address this problem, a GNSS antenna is provided that includes a hemispherical array of opposing metallized antenna elements that are coupled to a feed network through a pair of inter-element dipoles, thereby avoiding difficulties associated with direct electrical connections of the feed circuitry to the antenna elements.

Description

[0001] Cross Reference to Related Applications

[0002] This patent application claims priority to U.S. Provisional Patent Application 62 / 900,605, filed September 15, 2019, entitled “GNSS Antenna Element,” which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] This patent application relates to global navigation satellite systems, and in particular to antennas, antenna elements, and antenna assemblies using one or more pairs of antenna elements, each pair of antenna elements electromagnetically coupled with a dipole, with enhanced azimuth performance and / or wideband high-precision high-purity reception. BACKGROUND

[0004] Global satellite navigation systems or Global Navigation Satellite Systems (GNSS) utilize a network of geospatial positioning satellites to broadcast precise, synchronized navigation information, allowing determination of network time and geolocation through specialized GNSS receivers. In addition to a wide variety of geolocation uses, such receivers provide a ubiquitous global time reference, from consumer navigation devices to means of monitoring global warming, to precision agriculture, and of course military applications.

[0005] Modern Global Navigation Satellite System (GNSS) receivers are typically designed and configured to receive signals from multiple constellations, such as the European Galileo, Russian GLONASS, American GPS, and Chinese BeiDou global navigation systems, as well as at least two regional positioning and timing systems, such as the Indian NAVIC and Japanese QZSS systems. The most widespread use of Global Navigation Satellite System receivers is in consumer products, such as vehicle navigation systems, personal navigation systems, and the like, which when stationary, typically achieve an accuracy within 2 meters (4 meters diameter) 95% of the time, but with electronic processing and filtering in the related software processing the received GNSS signals, either smoothing statistical variations or snapping the position icon to the “most likely” feature on the map, consumer-level tracking often appears more accurate than it is in fact.

[0006] However, in other applications the reported position should be true (i.e. accurate) and reliable, often with higher reporting accuracy of the true position. Such applications can include surveying, autonomous vehicle control and / or guidance systems, precision agriculture, unmanned aerial vehicle (UAV) guidance and real-time navigation of aircraft, etc. Such high-precision GNSS receivers can provide a true position within 10 cm, or provide correction data within 2-3 cm, or provide a true position within 1-2 mm for integrated periodic fixed systems.

[0007] Such precise global navigation satellite system receivers receive signals at two or more frequencies and employ sophisticated models of the troposphere and ionosphere in order to estimate the signal travel times for a plurality of satellites used to establish a three-dimensional precise position. Furthermore, such systems utilize data transmitted by the satellites in the navigation signals, which are related to satellite position and time estimate errors, which can be caused by factors such as orbital conditions encountered by the satellites, etc.

[0008] Conceptually, this is all relatively straightforward. However, the peak radio frequency power flux density (PFD) of global navigation satellite system signals at the Earth's surface is approximately -120 dBm and decreases as the satellites approach the horizon. Therefore, if enough satellites are accessible, a GNSS receiver can selectively use signals from high-altitude satellites with higher PFD. However, it would be beneficial for a global navigation satellite system receiver to have the ability to track signals down to the horizon. The ability to achieve this is entirely dependent on the signal quality sent to the GNSS receiver by the GNSS antenna. In addition to clearly receiving the extremely low level radio frequency signals, it is also important that the phase of each received signal is independent of the angle of incidence on the antenna. Furthermore, the global navigation satellite system receiver must support the reception of circularly polarized signals.

[0009] This is because any real-time aspects of the received GNSS signal, such as polarization purity, phase integrity or signal quality (signal-to-noise ratio) or phase center, cannot be improved or restored. The only information available to the global navigation satellite system receiver is the signal on the global navigation satellite system antenna terminal, so the accuracy of the global navigation satellite system receiver system is first and foremost entirely dependent on the antenna.

[0010] Therefore, it would be beneficial to provide GNSS antenna elements and GNSS antenna systems to GNSS receiver designers that are free from one or more limitations of the prior art solutions.

[0011] Other aspects and features of the present application will become apparent to those of ordinary skill in the art upon reviewing the following description in conjunction with the accompanying figures. SUMMARY

[0012] It is an object of the present invention to alleviate the limitations of the prior art related to Global Navigation Satellite Systems, in particular related to antennas, antenna elements and antenna assemblies using one or more pairs of antenna elements, each pair electromagnetically coupled to a dipole by enhanced azimuthal performance and / or wideband high-precision high-purity reception.

[0013] According to one embodiment of the present invention, there is provided a method of providing an antenna, comprising:

[0014] providing a narrowband dipole electromagnetically coupled to a symmetrically arranged array of metallized petals, the array of metallized petals arranged centrally on a distally metallized ground plane, and a symmetrically opposite polar feed signal connected to a dipole feed connection centrally of the dipole; wherein

[0015] the antenna provides a wideband return loss and impedance at the dipole feed connection; and

[0016] the array of metallized petals provides a wideband low-loss matching feed network to improve the radiating efficiency of the combined structure.

[0017] According to one embodiment of the present invention, there is provided a method of providing an antenna, comprising:

[0018] providing a dipole electromagnetically coupled to a symmetrically arranged array of metallized petals, the dipole arranged centrally on a distally metallized ground plane, and a symmetrically opposite polar feed signal connected to a dipole feed connection centrally of the dipole, the dipole feed connection further connected to a feed connection limited centrally on the ground plane; wherein

[0019] the dipole and the symmetrically arranged array of metallized petals are arranged above the ground plane;

[0020] local current maxima of the array of metallized petals are offset from the center of the dipole; and

[0021] the ground plane is substantially free of dipole feed return currents.

[0022] According to one embodiment of the present invention, there is provided a method of providing an antenna, comprising:

[0023] providing a narrowband dipole electromagnetically coupled to a symmetrically arranged array of metallized petals, the array of metallized petals arranged centrally on a distally metallized ground plane, and a symmetrically opposite polar feed signal connected to a dipole feed connection centrally of the dipole; wherein

[0024] local current maxima in the metallized petals of the antenna are offset from the center of the dipole; and

[0025] a point of inflection in the magnitude of the current occurs centrally of the dipole in a combined radiating element consisting of the narrowband dipole and the symmetrically arranged array of metallized petals.

[0026] According to one embodiment of the present application, there is provided a method of providing an antenna, comprising:

[0027] providing a narrowband dipole electromagnetically coupled to a symmetric arrangement of metallized petals, the narrowband dipole being centrally arranged on a distal metallized ground plane, and a symmetric pair of feed signals connected to a dipole feed connection at the center of the dipole, wherein

[0028] the symmetric arrangement of metallized petals extends the bandwidth of the antenna structure to a greater bandwidth than the narrowband dipole.

[0029] According to one embodiment of the present application, there is provided an antenna, comprising:

[0030] a ground plane substrate having a defined center and comprising a first metallized layer forming a ground plane of the antenna;

[0031] a pair of opposing petals metallized on a petal substrate, wherein each petal of the pair of opposing petals is electrically isolated and geometrically identical and comprises a first wider end and a second distal narrower end arranged collinearly along a first petal axis, wherein the width of the metallized petal decreases gradually from the first wider end to the second distal narrower end, the proximal end of the pair of opposing petals is the distal second end, and the petal substrate center is located at the midpoint between the metallized petals;

[0032] a dipole substrate arranged between the ground plane and the petal substrate; a second metallized layer orthogonal to the ground plane, the second metallized layer being patterned to provide a dipole in the plane of the dipole substrate, the dipole substrate comprising a pair of identical dipole elements having a predetermined geometry arranged collinearly along a first dipole axis parallel to the ground plane substrate and connected at their proximal ends to a first dipole feed point and a second dipole feed point, respectively, wherein

[0033] the first petal axis and the first dipole axis are each linearly aligned with a center concentric with the center of the ground plane;

[0034] the petal substrate center is offset at a predetermined distance above the ground plane;

[0035] the petal substrate is curved symmetrically around the petal substrate center to form the metallized petals into identical three-dimensional shapes;

[0036] a spacing between a lower surface of each metallized petal of the pair of opposing petals and a nearest edge of an adjacent dipole element has a predetermined profile radially from the center of the ground plane; and

[0037] the dipole effectively constitutes a wideband distributed feed network by electromagnetic coupling without the need for direct electrical connection to the pair of opposing petals.

[0038] According to one embodiment of the present application, there is provided an antenna comprising:

[0039] a ground plane substrate comprising a first metallization layer forming an antenna ground plane;

[0040] a pair of opposing metallized petals arranged collinearly, each petal of the pair of metallized petals being identical and comprising a first wider end and a second distal narrower end, with a central axis longer than the width of the petal, wherein the width tapers from the first wider end to the second distal narrower end, the proximal end of the pair of opposing metallized petals being the second distal narrower end, and the midpoint between the pair of opposing metallized petals on their common linear axis defines a geometric center of the antenna; and

[0041] a dipole substrate comprising a second metallization layer, the second metallization layer being patterned to provide a narrowband dipole, the narrowband dipole comprising a pair of dipole elements and a pair of interconnecting tracks, the pair of interconnecting tracks connecting each element of the dipole to a predetermined metallized terminal of a pair of metallized terminals; wherein

[0042] a first axis of the narrowband dipole is aligned with the geometric center of the antenna and perpendicular to the ground plane;

[0043] a second axis of the narrowband dipole is parallel to the ground plane and aligned with the pair of opposing metallized petals;

[0044] the first wider end of each petal has a predetermined spacing from the first metallization layer; and

[0045] the pair of opposing metallized petals has a three-dimensional geometry such that the spacing between the inner surface of each metallized petal and the nearest edge of its associated dipole element varies in a predetermined manner with height from its first wider end to its second distal narrower end.

[0046] According to one embodiment of the present application, there is provided an antenna comprising:

[0047] a ground plane substrate having at least two metal layers, wherein the upper metal layer is continuously metallized to comprise a ground plane surface and has a central mounting slot and a plurality of peripheral mounting slots,

[0048] a dipole substrate having a balun and a narrowband dipole imprinted in a metal layer on the dipole substrate, the balun connected to a metallized terminal on a protruding lug at the center of the lower edge of the dipole substrate,

[0049] a three-dimensional structure comprising the dipole substrate mounted on the ground plane substrate, the protruding lug inserted into the central mounting slot, lying in a plane orthogonal to the ground plane,

[0050] the balun is connected to a feed circuit on a lower metal layer of the ground plane substrate,

[0051] a pair of opposing metallized petals etched in metal having a non-conductive edge on a semi-flexible dielectric substrate comprised of a first petal and a distal second petal, each petal being identical in size, each petal having a wider end and a distal narrower end, a central axis longer than the wider end, a width tapering between the wider end and the narrower end, each of the first and second petals being collinear, the proximal end of the first and second petals being the narrower end, a midpoint between the first and second petals defined as a geometric antenna center on an extended common axis,

[0052] each petal having a plurality of metallized tabs on the wider end electrically isolated from the metallized petal, the semi-flexible substrate having sufficient length to form an arch by inserting the tabs into peripheral mounting slots of the ground plane; and

[0053] the upper edge of the dipole substrate is sculpted to provide precise spacing between the opposing petal pair and the narrowband dipole, whereby the dipole effectively constitutes a wideband distributed feed network by electromagnetic coupling without direct electrical connection to the opposing petal pair.

[0054] According to one embodiment of the present invention, there is provided an antenna comprising:

[0055] a ground plane substrate comprising a first metallized layer forming an antenna ground plane;

[0056] a first pair of opposing metallized petals arranged collinearly, each petal of the first pair of opposing metallized petals being identical and comprising a first wider end and a second distal narrower end, a central axis longer than a width of the petal, wherein the width tapers from the first wider end to the second distal narrower end, a proximal end of the first pair of opposing metallized petals being the second distal narrower end, and a midpoint between the pair of opposing metallized petals on their common linear axis defining a geometric center of the antenna;

[0057] a second pair of opposing metallized petals arranged collinearly, each petal of the second pair of opposing metallized petals being identical and comprising a first wider end and a second distal narrower end, a central axis longer than a width of the petal, wherein the width tapers from the first wider end to the second distal narrower end, a proximal end of the pair of opposing metallized petals being the second distal narrower end, and a midpoint between the second pair of opposing metallized petals aligned with the geometric center of the antenna;

[0058] a first dipole substrate comprising a second metallization layer, the second metallization layer being patterned to provide a first narrowband dipole, the first narrowband dipole comprising a pair of dipole elements and a pair of interconnecting tracks, the pair of interconnecting tracks connecting each element of the first narrowband dipole to a predetermined metallized terminal of a pair of metallized terminals; and

[0059] a second dipole substrate comprising a third metallization layer, the third metallization layer being patterned to provide a second narrowband dipole, the second narrowband dipole comprising another pair of dipole elements and another pair of interconnecting tracks connecting each element of the second narrowband dipole to a predetermined metallized terminal of a pair of metallized terminals; wherein

[0060] the first narrowband dipole is aligned with a geometric center of the antenna and perpendicular to the ground plane;

[0061] the second narrowband dipole is aligned with the geometric center of the antenna, perpendicular to the ground plane and perpendicular to the first narrowband dipole;

[0062] a central axis of each lobe of the first pair of opposing metallized lobes is aligned with the first narrowband dipole;

[0063] a central axis of each lobe of the second pair of opposing metallized lobes is aligned with the second narrowband dipole;

[0064] the first wide end of each lobe has a predetermined spacing from the ground plane;

[0065] the first pair of opposing metallized lobes has a three-dimensional geometric shape such that a spacing between an inner surface of each metallized lobe and a nearest edge of a relevant dipole element of its first dipole element changes in a predetermined manner with height from its first, wider end to its second, narrower end; and

[0066] the second pair of opposing metallized lobes has a three-dimensional geometric shape such that a spacing between an inner surface of each metallized lobe and a nearest edge of a relevant dipole element of its second dipole element changes in a predetermined manner with height from its first, wider end to its second, narrower end.

[0067] According to one embodiment of the present invention, there is provided an antenna, comprising:

[0068] a ground plane substrate having at least two metal layers, wherein an upper metal layer is continuously metallized to comprise a ground plane surface, and having a first central mounting slot and a second central mounting slot, the second central mounting slot being concentric with and orthogonal to the first central mounting slot, and a plurality of peripheral mounting slots,

[0069] a first and second dipole substrate of identical external dimensions, each uniformly etched with a balun and a narrow band dipole printed in a metal layer on the dipole substrate, the balun connected to metallized terminals on a lower edge center protruding lug on the dipole substrate, the first and second dipole comprising interlocking slots for assembly of a three dimensional cross dipole structure,

[0070] an assembly consisting of an orthogonal dipole structure mounted on the ground plane substrate by inserting each protruding lug into the first and second center mounting slots, the first and second balun feed connections comprising a feed circuit of first and second outputs by an RF 90 degree coupler,

[0071] a first and second pair of opposing wings, each pair of wings consisting of a first wing and a distal second wing, the first wing and the distal second wing etched in a metal having a non-conductive edge, each wing having a wider end and a distal narrower end on each of the identical dimension semi-flexible substrates, the center axis longer than the wider end and the width between the wider end and the narrower end tapering, the first and second wings collinear, the proximal end of the first and second wings being the narrower end, the axes of the first and second pair of opposing wings being orthogonal to each other, the common midpoint between the first and second wings on each of the extended axes defining a geometric antenna center.

[0072] each of the metallized wings having a plurality of metallized tabs at the wider end, electrically isolated from the metallized wing, the semi-flexible substrate having sufficient length to form a dome structure by inserting the tabs into the peripheral mounting slots in the ground plane, the pair of wings aligned along the axis of the cross dipole,

[0073] the upper edges of the first and second dipole substrates sculpted to identical shapes to provide precise spacing between the opposing wing pairs and the cross narrow band dipole, whereby the dipoles are effective by electromagnetic coupling to include a wideband distributed feed network for a circular polarized antenna, wherein none of the opposing wing pairs are directly connected.

[0074] According to one embodiment of the present invention, there is provided an antenna comprising:

[0075] a ground plane substrate having at least two metal layers, wherein the upper metal layer is continuously metallized to include a ground plane surface, and having a first center mounting slot and a second center mounting slot, the first and second center mounting slots concentric and orthogonal to the first center mounting slot, and a plurality of peripheral mounting slots,

[0076] First and second dipole substrates of identical external dimensions, each uniformly etched with a balun and a narrowband dipole printed in a metal layer on the dipole substrate, the balun connected to metallized terminals on a lower edge center protrusion tab on the dipole substrate, the first and second dipoles including interlocking slots for assembly of a three-dimensional cross-dipole structure,

[0077] An assembly including an orthogonal dipole structure mounted on the ground plane substrate by inserting each of the protrusion tabs into the first and second center mounting slots, and four gap support substrates mounted perpendicular to the ground plane, each rotated 45 degrees with respect to any one of the cross-dipole axes so as to similarly be disposed in each quadrant of the cross-dipole structure, each gap support substrate having the same upper profile as the cross-dipole,

[0078] First and second outputs of a feed circuit comprised of a radio frequency 90 degree coupler when the first and second balun feed lines are connected

[0079] First and second pairs of first, second, third and fourth petals, each pair of petals comprised of a first petal and a distal second petal, the first and distal second petals etched on a metal having a non-conductive edge, on each of the identical dimensioned semi-flexible substrates, each petal having a wider end and a distal narrower end, the central axis longer than the wider end, the first and second petals being collinear, the proximal ends of the first and second petals being the narrower ends,

[0080] The axes of any second pair of petals rotated 45 degrees with respect to the axes of the first pair of petals, the rotation between the third pair of petals and the second pair of petals, the fourth pair of petals and the third pair of petals being equal, there being a common midpoint between the first and second petals on each of the extension axes of each pair of petals, defined as the geometric antenna center,

[0081] Each of the metallized petals having a plurality of metallized tabs at the wider end, electrically isolated from the metallized petal, the semi-flexible substrates having sufficient length to form a dome structure by inserting the tabs into the peripheral mounting slots in the ground plane, at least one of the pairs of petals aligned along the axis of one of the cross-dipoles,

[0082] The upper edges of the first and second dipole substrates are identically sculpted to provide precise spacing between the opposing pairs of petals associated with each of the cross-narrowband dipoles, the upper edges of the gap support substrates further sculpted to the same shape as the dipole substrates, whereby the dipoles are effectively electromagnetically coupled to include a wideband distributed feed network for a circularly polarized antenna, wherein none of the opposing pairs of petals are directly connected.

[0083] According to one embodiment of the present application, there is provided a method of receiving a circularly polarized radio frequency signal, comprising:

[0084] providing a first pair of opposing metallized petals arranged above the ground plane and having a predetermined three-dimensional profile with respect to the ground plane;

[0085] providing a second pair of opposing metallized petals arranged above the ground plane and orthogonal to the first pair of opposing metallized petals and having the same predetermined three-dimensional profile as the first pair of opposing metallized petals;

[0086] a first dipole comprising a pair of first dipole elements aligned with the first pair of opposing metallized petals such that;

[0087] a second dipole comprising a pair of second dipole elements aligned with the second pair of opposing metallized petals; wherein

[0088] a distance from an upper edge of each first dipole element to a respective petal of the first pair of opposing metallized petals has a predetermined profile as a function of an elevation angle from the ground plane; and

[0089] a distance from an upper edge of each second dipole element to a respective petal of the second pair of opposing metallized petals has a predetermined profile as a function of an elevation angle from the ground plane.

[0090] According to one embodiment of the present application, there is provided a method of receiving a circularly polarized radio frequency signal, comprising:

[0091] providing a first narrowband dipole electrically connected to a feed network;

[0092] providing a second narrow dipole orthogonal to the first dipole and electrically connected to the feed network;

[0093] providing a first pair of opposing metallized petals arranged above the ground plane and having a predetermined three-dimensional profile with respect to the ground plane;

[0094] providing a second pair of opposing metallized petals arranged above the ground plane and orthogonal to the first pair of opposing metallized petals and having the same predetermined three-dimensional profile as the first pair of opposing metallized petals; wherein

[0095] the first dipole and the first pair of opposing metallized petals are axially aligned with each other;

[0096] the second dipole and the second pair of opposing metallized petals are axially aligned with each other;

[0097] the first pair of opposing metallized petals provide a wideband antenna element that is radiatively coupled to the feed network via the first narrowband dipole; and

[0098] The second pair of opposing metallized petals provide a wideband antenna element that is coupled to the feed network via a second narrowband dipole radiation, respectively.

[0099] According to one embodiment of the present invention, there is provided an antenna comprising:

[0100] A ground plane substrate having at least two metal layers, wherein the upper metal layer is continuously metallized to include a ground plane surface and has a central mounting slot and a plurality of peripheral mounting slots,

[0101] A first pair of opposing petals etched in metal on a semi-flexible substrate, wherein each petal of the pair of opposing petals is electrically isolated, geometrically identical, includes a first wide end and a second distal narrow end, the first wide end and the second distal narrow end are arranged collinearly along a first petal axis parallel to the ground plane, the proximal end of the pair of opposing petals is the distal second end, a petal substrate center is defined as the midpoint between the metallized petals; and

[0102] A second pair of opposing petals etched in metal on a semi-flexible substrate, configured the same as the first pair of opposing petals, arranged along a second petal axis parallel to the ground plane and orthogonal to the first petal axis, arranged concentrically with the first pair of petals,

[0103] A plurality of metallized connection patches arranged sequentially at the distal end of each petal substrate center and further than the wider end of each metallized petal, connected to an adjoining metallized area, wherein each metallized connection patch of the plurality of connection patches is electrically isolated from the second pair of petals to the relevant petal of the first pair of opposing petals or the petal;

[0104] A first dipole substrate arranged between the ground plane and the petal substrate, the petal substrate is orthogonal to the ground plane, the petal substrate has a second metallized layer that is patterned to provide a first dipole in the plane of the dipole substrate, the first dipole substrate includes a first pair of identical dipole elements connected at their proximal end to provide a first balanced dipole feed; and

[0105] A second dipole substrate configured the same as the first dipole substrate, the first dipole substrate is orthogonal to the ground plane, the ground plane is arranged along a second dipole axis orthogonal to the first dipole axis, the second dipole substrate includes a second pair of identical dipole elements connected at their proximal end to provide a second balanced dipole feed; wherein

[0106] The semi-flexible substrate has sufficient length to form an arched structure by inserting the metallized connection patches into the peripheral mounting slots in the ground plane;

[0107] each metallized region is connected to ground by the metallized connecting tab;

[0108] engraving the upper edge of the first dipole substrate to provide a predetermined spacing between the inner surface of each winglet of one of the first pair of opposing winglets or the second pair of opposing winglets and the first pair of identical dipole elements;

[0109] engraving the upper edge of the second dipole substrate to provide a predetermined spacing between the inner surface of each winglet of the first pair of opposing winglets or the second pair of opposing winglets and the second pair of identical dipole elements;

[0110] wherein the first and second dipoles comprising a broadband distributed feed network on two orthogonal axes by electromagnetic coupling, without direct electrical connections between the first and second dipoles, the first pair of winglets and the second pair of winglets.

[0111] Other aspects and features of the present application will become apparent to those of ordinary skill in the art upon review of the following description of specific embodiments of the application in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0112] Embodiments of the application will now be described, by way of example only, with reference to the accompanying drawings in which:

[0113] Figure 1A and 1B depicting lower and upper perspective views of a GNSS antenna according to embodiments of the application;

[0114] Figure 2 depicting a lower perspective view of a GNSS antenna according to embodiments of the application with a printed circuit board (PCB) removed;

[0115] Figure 3 depicting an upper perspective view of a GNSS antenna according to embodiments of the application with winglets removed;

[0116] Figure 3B depicting a partially exploded assembly of a dipole circuit, support and mounting block for a GNSS antenna according to embodiments of the application;

[0117] Figure 4 exploded perspective view of a pair of orthogonal positioning dipoles for a GNSS antenna according to embodiments of the application;

[0118] Figure 5 and Figure 6 depicting a pair of dipoles for a GNSS antenna according to embodiments of the application;

[0119] Figure 7A depicting a perspective view of a winglet assembly comprising an array of winglets for a GNSS antenna according to embodiments of the application;

[0120] Figure 7B Depiction of a planar perspective schematic and photograph of a winglet array for a GNSS antenna according to embodiments of the present application;

[0121] Figure 7C Depiction of a planar perspective schematic of a winglet array for a GNSS antenna according to embodiments of the present application;

[0122] Figure 8 Depiction of a photograph of a GNSS antenna according to embodiments of the present application, the antenna using 8 winglets in a winglet array;

[0123] Figure 9 Depiction of a photograph of a GNSS antenna according to embodiments of the present application using 4 winglets in a winglet array;

[0124] Figure 10A and 10B Depiction of a planar perspective schematic and photograph, respectively, of a winglet array for a GNSS antenna according to embodiments of the present application employing 4 winglets;

[0125] Figure 11 Depiction of a planar perspective schematic of a winglet array for a GNSS antenna according to embodiments of the present application using a pair of winglets;

[0126] Figure 12 Depiction of a detail of a winglet and its label for a GNSS antenna according to embodiments of the present application;

[0127] Figure 13A Depiction of a cross-sectional view of an antenna according to embodiments of the present application, the antenna utilizing a dipole electromagnetically coupled to a pair of winglets;

[0128] Figure 13B Depiction of a dipole structure with dual feed points (FPs) and with a single feed point having an integrated balun, respectively, according to embodiments of the present application;

[0129] Figure 14 Depiction of a schematic of a dipole and a dipole with a ground plane implemented in embodiments of the present application;

[0130] Figure 15 Depiction of a photograph of a GNSS antenna and its simulated current distribution according to embodiments of the present application;

[0131] Figure 16 and Figure 17 Depiction of left and right circular polarization versus elevation antenna responses for a GNSS antenna according to embodiments of the present application at GPS L5, GPS L2, Galileo E6, and GPS L1 frequencies, showing constant amplitude responses to signals coming at specific elevations, independent of azimuth;

[0132] Figure 18 A GNSS antenna according to embodiments of the application is described in comparison to a commercial off-the-shelf GNSS antenna for the same application;

[0133] Figure 19 Right hand circular polarization (RHCP) gain of a GNSS antenna according to embodiments of the application is depicted at zenith and 10° elevation for all GNSS frequencies;

[0134] Figure 20 Radiation efficiency of a GNSS antenna according to embodiments of the application is depicted for all GNSS frequencies;

[0135] Figure 21 Axial ratio (AR) of a GNSS antenna according to embodiments of the application is depicted at different elevations;

[0136] Figure 22 AR performance of a GNSS antenna according to embodiments of the application is depicted on the horizon in comparison to a commercial off-the-shelf GNSS antenna for the same application;

[0137] Figure 23 Phase center variation (PCV) of a GNSS antenna according to embodiments of the application is depicted on the horizon in comparison to a commercial off-the-shelf GNSS antenna for the same application; and

[0138] Figure 24 Results of a GNSS antenna CAD according to embodiments of the application are described, the antenna employing dipole elements and a pair of wings. DETAILED DESCRIPTION

[0139] The present application relates to global navigation satellite systems, and more particularly to antennas, antenna elements, and antenna assemblies employing one or more pairs of antenna elements, each pair of antenna elements electromagnetically coupled with a dipole, having enhanced azimuth performance and / or wideband high precision high purity reception.

[0140] The following description provides representative embodiments only and is not intended to limit the scope, applicability or configuration of the application. Rather, the following description of the embodiments will provide an enabling description for one of ordinary skill in the art to implement one or more embodiments of the application. It should be understood that various changes can be made in the function and arrangement of elements without departing from the spirit and scope of the claims as set forth below. As such, the embodiments are to be considered in a descriptive sense only and not for purposes of limitation. The various embodiments presented are not necessarily to be used exclusively with other embodiments. Rather, the various embodiments can be selectively combined with each other and / or the various features from them can be individually selected to form new combinations.

[0141] Reference throughout this specification to "one embodiment", "an embodiment", "some embodiments" or "other embodiments" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the application but not necessarily in all embodiments. The appearance of the phrases "in one embodiment", "in an embodiment", "in some embodiments" or "in other embodiments" in various places in the specification are not necessarily all referring to the same embodiment. The terms "a" or "an", as used herein, should not be interpreted as meaning only one but rather one or more. It will be understood that if a specific feature, structure, or characteristic is described as "can", "might", or "may" be included, that feature, structure, or characteristic is not necessarily included with all embodiments.

[0142] Reference to terms such as "left", "right", "top", "bottom", "front" and "back" are intended to be used to describe the orientation of particular features, structures or elements in the drawings of the embodiments of the application. It is clear that such directional terms have no specific meaning in relation to the actual use of the device as the user can use the device in a number of orientations.

[0143] Reference to the terms "comprise", "comprising", "consisting of and grammatical variants thereof does not exclude additional components, features, steps, integers or groups thereof and the terms are not to be construed as specifying components, features, steps or integers. Likewise, the phrase "consisting essentially of does not exclude additional components, steps, features, integers or groups thereof, but the additional components, steps, features, integers or groups thereof do not materially alter the basic and novel characteristics of the claimed composition, device or method. If the specification or claims refer to "additional" elements in providing a particular feature or step, this does not preclude there being more than one of the additional element.

[0144] In terms of alignment and / or orientation, references to the terms "perpendicular", "along", "parallel", and their grammatical variants should not be taken as absolute, but rather as tolerant of variations, such that the orientations and / or alignments are "substantially" as shown. Such tolerances are determined, for example, by manufacturing tolerances, performance tolerances, manufacturing costs, and the like.

[0145] As used herein, "azimuth angle" refers to the angle of rotation in the X-Y plane with respect to a defined direction, centered at an origin.

[0146] As used herein, "elevation angle" or "height" refers to the angle between the wave normal of an incident plane wave and the X-Y (ground) plane. Thus, a wave grazing the horizon has an elevation angle close to zero, while a wave that is normally incident has an elevation angle of 90 degrees.

[0147] As used herein, "axial ratio" refers to a measure of the degree to which a circularly polarized signal of an unwanted polarization (second sense of rotation) can be rejected by an antenna relative to a wanted polarization (first sense of rotation), and is a measure of the ability to reject multipath signals, which is an important parameter for precision antennas.

[0148] As used herein, "phase center offset" refers to the concept that there is a region associated with an antenna that tends towards a point of a perfect antenna, within which region or at which point all signals can be considered to be received at or transmitted from. This is a virtual region / point in space, typically directly above the midpoint of the physical antenna, and is a measure of the knowledge limitation of the antenna's position in space.

[0149] As used herein, "phase center variation" refers to the measurement of the apparent phase center movement of a plane wave over all angles of incidence (i.e. around all azimuth angles and all elevation angles) and all frequencies within a bandwidth. An ideal antenna has zero phase center variation.

[0150] As used herein, "petal" refers to a metallized antenna structure, which can be free-standing, supported by a frame, patterned on a substrate, or on a substrate or carrier supported by a frame that provides the receiving antenna elements for a GNSS antenna. For simplicity in the following mechanical description of GNSS antennas according to embodiments of the application, the term petal refers to the metallized antenna structure, any substrate or carrier, and auxiliary elements used to mechanically connect / retain the petal discretely or in the form of an array of petals with one or more other elements of the GNSS antenna. In the following functional description of GNSS antennas according to embodiments of the application, the term petal refers to the metallized antenna structure.

[0151] As used herein, "dipole antenna" (often referred to as a dipole) refers to, but is not limited to, any of a class of antennas that produce an approximate fundamental electric dipole radiation pattern, the fundamental electric dipole having a radiating structure that supports a line current that is energized such that there is only one node at each end of the current.

[0152] As used herein, "radome" refers to, but is not limited to, an environmental enclosure or cover in which an antenna, such as a GNSS antenna, is encapsulated that is transparent to wireless signals in the frequencies of interest.

[0153] As used herein, GNSS "rover" antenna refers to, but is not limited to, a GNSS antenna that addresses real-time kinematic (RTK) and mobile (rover) applications.

[0154] As used herein, "CubeSat" refers to, but is not limited to, a U-class spacecraft, which is a small satellite made up of multiples of 10 cm x 10 cm x 10 cm (4" x 4" x 4") cubic units. CubeSats can use commercial off-the-shelf (COTS) components to make their electronics and structures.

[0155] As noted above, GNSS receivers have widespread applications in both civilian and military markets. One primary configuration for civilian dual-frequency receivers is to use the L1 + L2 bands of the GPS system (formerly known as Navstar GPS). Table 1 lists the operating bands for GPS L1 and GPS L2, as well as the bands for other major GNSS systems introduced in the 2000s, namely, Beidou, Galileo, GLONASS, GPS, and NAVIC.

[0156]

[0157]

[0158]

[0159] Table 1: Operating frequencies for GNSS systems (closest to 1 MHz)

[0160] In addition, the deployment of satellites that also provide navigation signals on the L5 band is increasing, and correspondingly GNSS receivers that are compatible with L1 + L5 signals or L1 + L2 + L5 signals discretely. L5 provides several benefits, including but not limited to being twice that of L2, being located within a band designated by the International Telecommunications Union (ITU) for aeronautical radio navigation service (ARNS), being less susceptible to interference from terrestrial navigation devices, and sharing the same frequency space as the E5A signal of Galileo. Similarly, GNSS receivers that are compatible with both the GPS and Galileo systems have benefits, such as allowing use of a device containing such a receiver in areas where one or both GNSS systems are accessible.

[0161] Section 1 : Design Principles

[0162] The design of GNSS antennas needs to consider a range of characteristics, such as the ability to track satellites at low elevation angles, phase center variations (PCV), antenna efficiency and impedance, axial ratio and up-down ratio (UDR), antenna bandwidth, etc., while also providing a lightweight, compact and robust form factor. While the following description and examples of the present invention are directed to GNSS rover antennas, it will be apparent to those skilled in the art that the outlined design and principles can be used in the design and implementation of GNSS antennas for other applications and scenarios without departing from the scope of the invention.

[0163] 1A: Low Elevation Tracking: The use of Precise Point Positioning (PPP) and satellite broadcasted PPP correction data has been widely adopted. The PPP correction data is broadcasted by geostationary satellites that typically propagate in low elevation directions towards most of the population dense areas in Europe and North America. The link margin for L-band signals is typically low (or thin), so increasing the gain at these elevations is an important attribute for GNSS antennas. This problem is more severe at the edge of the satellite beam and in northern latitudes where the link margin is further challenged, and a difference of only 1 dB in antenna gain or antenna noise figure can have a significant impact on the availability of corrections. One key design parameter in this regard is the antenna gain-to-noise temperature (G / T), which is the ratio of the antenna element gain divided by the receiver system noise temperature, and is typically determined by the antenna noise figure. For example, the inventors target a G / T of -25.5 dB / K for a GNSS antenna at an elevation of 10° according to embodiments of the present invention.

[0164] The gain of most prior art GNSS antenna elements, such as patches and cross-dipoles, rapidly decays as the elevation decreases towards the horizon. Due to the presence of the ground plane, the polarization response of these prior art GNSS antenna elements also becomes linear at lower elevations, which is necessary to increase the half-space gain above the antenna. Improved gain close to the horizon also improves the receiver's ability to track low elevation satellites, while increasing the dilution of precision (DOP), which is a measure related to the accuracy of pseudorange measurements. Most commercial GNSS rover antennas have a peak gain at zenith of about 3.5 dBic to 5 dBic, with a roll-off of 10-12 dB at the horizon. Typically, this provides at most about -5 dBic of antenna gain in the horizontal direction, which is not sufficient to optimize L-band correction usage. Different antenna types, such as helical elements, have been proposed in the prior art to overcome this problem, but their cylindrical and longer length makes them unsuitable for many applications, especially rough-terrain (or rover) applications. In addition, helices are affected by backlobe, which can make the antenna more susceptible to receiving multipath signals incident below the antenna's positive half-space.

[0165] Following as shown in Sections 2 and 3, the inventors have established a GNSS rover antenna that utilizes wideband radiating elements (hereinafter “petals”) around a distributed feed network in order to achieve superior right-hand circular polarization (RHCP) gain at low elevation angles in a high-performance GNSS antenna with a small form factor, but assembly that provides improved ease of manufacture and reproducibility.

[0166] 1B: Phase Center Variation (PCV): The phase center of an ideal antenna is a notional point in space at which all signals are received or transmitted, regardless of the frequency, elevation, or azimuth of signal incidence. In real life, however, the phase center of an antenna is not quite so neat, and PCV is a measure of the variation of the “zero” phase point with frequency, elevation, and azimuth. Correction data for phase center variation is typically encoded in a standardized file, such as an Antenna Exchange Format (ANTEX) file, which can be applied simultaneously for precision applications. Azimuth is typically unknown for a rover antenna, so errors at specific azimuths cannot be accounted for. PCV correction data provided in an ANTEX file is typically provided as a function of elevation and frequency, but average azimuth data for each elevation and frequency (designated as “noazi” corrections). Thus, corrections can be made for each frequency and elevation, but errors due to variation in azimuth PCV cannot be corrected in the receiver. For RTK systems, the net system error is the RMS sum of the base station antenna and the rover antenna phase center variation. Smaller GNSS rover antennas can typically be accommodated, which can often provide PCV close to + / - 1 mm (e.g., from Trimble® VeraPhase TM or VeraChoke TM antenna). In many cases, however, the precision of a combined system depends largely on the PCV of the smaller GNSS rover antenna. Thus, azimuthal symmetry of a GNSS antenna is key, even with correction data. Accordingly, the design approach taken by the inventors focuses on symmetry of the antenna element structure and mechanical housing design.

[0167] 1C: Antenna Efficiency and Impedance: Antenna efficiency (AE) can be defined narrowly as the copper loss of a radiating element, but feed network losses also contribute, so the design goal should be optimization of both. It is generally known to those skilled in the art that physically wide radiating elements are a key requirement for wider bandwidth, and copper is a good compromise for a heat sink metal. In the design described in Section 2 below, wide physical petals are used, although it is apparent that alternative petal designs with narrower geometry can be used without departing from the scope of the invention in narrowband applications. Similarly, the experimental results described in Section 3 make use of copper as the petal metallization, although it is apparent that other materials could be used, such as silver, which provides better electrical conductivity, but at a higher cost.

[0168] However, as evident from Section 2 of the GNSS antenna according to embodiments of the present application, the petal is a parasitic resonator tightly coupled to the distributed feed network, which is inherently narrowband. Thus, the resulting wideband response of the GNSS antenna according to embodiments of the present application is provided by the loading on the feed network from the excellent wideband radiation resistance of the petal.

[0169] This arrangement is chosen because the impedance generated at the non-embedded antenna feed terminal is close to the desired ideal impedance (50 Ohms), thus requiring minimal impedance matching. The near-ideal matching over a wide bandwidth is very important because it allows the use of very short transmission lines (typically less than λ / 4) to convert the impedance to ideal, which can include an embedded infinite balun.

[0170] In the following Section 2 regarding Figures 1A-10B In the described and depicted embodiments of the present application, the petal is used together with a dipole for each orthogonal excitation axis, where the pair of orthogonal excitation axes are electrically independent and highly electrically isolated (better than -30 dB within the GNSS antenna manufactured according to embodiments of the present application), even with parasitic petal coupling. To achieve the required circular polarization, the two axes are then independently driven in phase quadrature within the microwave / RF circuitry associated with the GNSS antenna, e.g., which can be implemented on a PCB or external circuitry forming part of the GNSS antenna. As evident from the results presented in Section 4, the resulting GNSS antenna according to embodiments of the present application combines an inherently efficient parasitic petal with a low-loss distributed feed network, resulting in a highly efficient GNSS antenna structure providing superior performance over prior art solutions.

[0171] 1D: Axial Ratio (AR) and Up-Down Ratio (UDR): AR represents the antenna’s ability to receive circular signals, while UDR represents the ratio of the gain pattern amplitude at positive elevation angle (a) to the maximum gain pattern amplitude at its mirror (-a). Good AR and UDR are required over the entire bandwidth of the antenna to ensure purity in receiving RHCP signals within GNSS systems and to mitigate multipath effects. GNSS signals reflected from metallic structures such as the ground, buildings, or vehicles are delayed, and their purity in RHCP signals is reduced due to left-hand circular polarization (LHCP) signals. Since the GNSS antenna according to embodiments of the present application is designed to provide improved gain at low elevation angles, very low AR and high UDR are particularly important to mitigate multipath interference.

[0172] 1E: Wide antenna bandwidth: A GNSS antenna with wide frequency band allows the system using it to implement positioning from GNSS signals coming from multiple constellations, for example from satellites of multiple GNSS systems. Recent studies have shown that interoperability between different satellite constellations can significantly improve navigation and positioning performance. In particular, it has been demonstrated that a wideband GNSS antenna allows to implement three-carrier and multi-carrier ambiguity resolution techniques to obtain the highest possible accuracy. In challenging environments, some signals can be occasionally blocked by foliage, buildings, etc. These blocked signals can then be replaced by satellite signals from other constellations that are not subject to such blockage. It would therefore be beneficial for a GNSS antenna to be able to receive over the entire GNSS frequency band from 1.15 GHz to 1.60 GHz.

[0173] 1F: Light, robust, compact: Small GNSS antennas are under constant pressure, but precise rover GNSS antennas typically need to receive signals at low and high GNSS frequencies. There is an unavoidable constraint that limits the bandwidth of small antennas, so in order to provide a full-bandwidth rover GNSS antenna, it is inevitable to tend to be larger. With the consideration of performance, the inventors have established additional mechanical targets for embodiments of the present invention, although it is clear that such mechanical constraints can be different in other systems, so GNSS antennas with different configurations can be used, but still make use of the design concepts and methods outlined in this specification and remain within the scope of the present invention.

[0174] According to the present invention, a GNSS antenna according to embodiments of the present invention (the result of which is given in Section 4) is suitable for a small and light radiating element (given the full bandwidth requirement) with a ground plane size of about 100 mm (4 inches), an element height of 30 mm or less (1.2 inches or less), and a weight of 100 grams or less (3.5 ounces or less). Obviously, smaller versions of such GNSS antennas can be implemented with embodiments of the present invention, although with different performance. Applications of GNSS antennas according to embodiments of the present invention can include, but are not limited to, enclosed antennas (e.g. RTK rovers) as well as light antennas suitable for mobile applications such as drones, unmanned aerial vehicles, CubeSats, etc.

[0175] In the following description (as illustrated in Figures 1 to Figure 24 In the following description (as illustrated in Figures 1 to

[0176] • Section 2 relates to the mechanical design of a dipole-fed antenna element and system according to embodiments of the present invention;

[0177] • Section 3 relates to the working principle of a dipole-fed antenna element and system according to embodiments of the present invention;

[0178] • Section 4 relates to the performance of the dipole-fed antenna element and system according to embodiments of the present application; and

[0179] • Section 5 relates to a comparison of the dipole-fed antenna element and system according to embodiments of the present application with the prior art.

[0180] Section 2: Mechanical design of the dipole-fed antenna element and system

[0181] In the following description with respect to Figures 1 to Figure 15 , embodiments of the present application with respect to GNSS antenna structures are described. As described in Section 1 above, there are several performance aspects of GNSS antennas that need to be simultaneously optimized. The basic design principles of the GNSS antenna according to embodiments of the present application are described in Section 4 below with respect to Figures 14-15 , while the performance of a prototype GNSS antenna is described in Section 3 below with respect to Figures 16-22 . Thus, the design principles established by the inventors include radiating lobes that are electromagnetically (i.e. radiatively) coupled to dipoles.

[0182] Thus, with reference to Figure 13A , a minimum structure of the antenna is depicted in cross-sectional view 1300A, in which these design elements are embodied, including a pair of lobes 110 having a dipole formed by first and second dipole elements 1320A and 1330A. As shown, the first and second dipole elements 1320A and 1320B are formed on a carrier 1310A (e.g. a PCB) and are coupled to first and second feed points (FP) 1330A and 1330B, respectively. Figure 11 A plan view 1100 of a pair of lobes 110 is depicted in , in which the two lobes 110 are clearly opposite, having a common central axis X-X that will be aligned with the carrier 1310 and the first and second dipole elements 1310A and 1310B, respectively. In plan view 1100, the distal end of each lobe 110 is also depicted with a pair of lugs 130, as described below with respect to Figure 1, and pads 1010, as described below with respect to Figure 10. As shown, the pair of lobes 110 are connected by a non-metallized portion of a carrier element 1110, on which the lobes 110 are formed.

[0183] With reference to Figure 13Brespectively. In the first electrical configuration 1300B, the first dipole element 1340A is coupled to the first FP 1360A via a first track 1350A, which is part of a first transmission line 1355A between the first FP 1360A and the first dipole element 1340A. Similarly, the second dipole element 1340B is coupled to the second FP 1360B via a second track 1350B, which is part of a second transmission line 1355B between the second FP 1360B and the second dipole element 1340B. Thus, the dipole depicted in the first electrical configuration 1300A is driven by both the first FP 1360A and the second FP 1360B. Optionally, the first and second dipole elements 1320A and 1320B are also implemented on the other side of the carrier 1310B, where the two electrical structures on either side of the carrier 1310B are electrically connected by a plurality of vias, which are not depicted for clarity.

[0184] In the second electrical configuration 1300C, the first dipole element 1370A is coupled to the first FP 1390A via a first feed track 385A, and the second dipole element 1370B is coupled to a second feed track 385b. Also depicted is a first transmission line 1380A coupled to the first FP 1390A and the second dipole element 1370B, which terminates at a pad 1395 on the second dipole element 1370B. In contrast to the first electrical configuration 1300B, in which the dipole comprising the first and second dipole elements 1340A and 1340B is coupled to unbalanced lines from the first and second FPs 1360A to 1360B, respectively, the dipole in the second electrical configuration 1300C is fed from a single FP 1390, and comprises a balanced-unbalanced (balun) connection, so that the first and second dipole elements 1370A, 1370B operate in a balanced fashion, with the feed to the first FP 1390A being unbalanced.

[0185] Beneficially, the integrated balun in the second electrical configuration 1300C has an electrical impedance close to the target 50Ω impedance as compared to the first electrical configuration 1300B, where matching to the target 50Ω impedance at the FP 1390A is achieved by appropriate design parameters of the transmission lines comprising the first feed track 385A and the first transmission line 1380A. Optionally, the first and second dipole elements 1370A and 1370B, with or without the first and second feed tracks 385A and 1385B, respectively, are also implemented on the other side of the carrier 1310B, where the two electrical structures on either side of the carrier 1310C are electrically connected by a plurality of vias, which are not depicted for clarity.

[0186] These GNSS antennas employ a receiving element, each receiving element comprising a pair of opposing petals electromagnetically coupled to a dipole and in the dipole electromagnetically coupled to an RF receiver circuit. Subsequently, the working principle of a GNSS antenna employing the described receiving element is outlined, the receiving element comprising a pair of opposing petals electromagnetically coupled to a dipole.

[0187] Reference is made to Figure 1A and 1B , depicting a lower and upper perspective view 100A and 100B, respectively, of a GNSS antenna according to embodiments of the present application. Considering the initial lower perspective view 100A of a GNSS antenna according to embodiments of the present application in Figure 1A , the petals 110 array is mounted onto a printed circuit board (PCB) 120 by means of lugs 130 inserted onto the petals 110 of the slots within the PCB 120. This mounting of the petals 110 on the substrate on which the metallization areas are formed is described and depicted in more detail below with respect to Figure 12 . Arranged on the PCB 120 are electronics 140, which are coupled to an RF connector 150 and to a plurality of dipoles, not visible in the lower perspective view 100A, but arranged in the GNSS antenna according to embodiments of the present application. Reference is now made to Figure 1B , the upper perspective view 100B of a GNSS antenna according to embodiments of the present application, the petals array 110 is similarly depicted as mounted on a printed circuit board (PCB) 120. As Figure 1B indicated, the array of petals 110 comprises eight (8) petals 110, although as described below with respect to Figures 10 to Figure 12 , antennas utilizing embodiments of the present application can use 2 or 4 petals 110. However, other counts of petals 110 can be used, where N, the number of petals 110 is an even integer. Figure 1B Mounting holes 160 within the PCB 120 are also depicted in

[0188] In Figure 1A and 1B , the first and second artifacts 170A and 170B are artifacts produced by computer aided design (CAD) software for generating the images shown in Figures 1A-6 , Figure 6 A to 7B and Figure 8 , respectively. The first artifact 170A is a side view of the elements within the petals 110 array, which supports the carrier and / or substrate of the petals 110 array being realized directly by the petals 110 and / or metallization. The second artifact 170B is a top view of these elements. Thus, the first and second artifacts 170A and 170B appear due to the CAD software viewing the petals array 110 and / or the carrier of the petals 110 as transparent.

[0189] The electronic device 140 provides microwave / RF circuitry that combines the received RF / microwave signals at the feed points (FPs) of the multiple dipoles to generate an RF / microwave output signal coupled to the RF connector 150 in the case where the GNSS antenna is a receiver. Thus, considering the case where a pair of dipoles are arranged at right angles to each other, there are 4 FPs. Thus, the electronic device 140 includes a pair of hybrid couplers, each coupling the RF / microwave signals from a pair of FPs to a common output port, and a balun that receives signals from the common output ports of the pair of hybrid couplers and combines them to generate a signal coupled to the RF connector 150 at the output of the balun. If the microwave / RF signals from the FPs have a relative phase difference of the sequence 0°, 90°, 180° and 270°, these signals are initially combined within each hybrid coupler and then within the balun. Thus, based on the sequence of phases coupled from the FPs to the hybrid couplers, the GNSS antenna is operable to receive right-hand circularly polarized signals. Alternatively, the GNSS antenna can be configured to receive left-hand circularly polarized signals, or in other embodiments of the application, to provide a GNSS antenna for a transmitter that produces right-hand or left-hand polarized signals. Optionally, in other embodiments of the application, the balun can be a transformer. Figure 1A In the case of the second electrical configuration 1300C, the four FPs are located within the region 180 that protrudes through the PCB 120.

[0190] Although the embodiments of the application described and depicted below employ a pair of orthogonally arranged dipoles, providing 4 fps, other configurations can be implemented without departing from the scope of the application. For example, as described above and depicted in Figures 2-10B FIG. 6, the dipoles can employ integrated baluns such that only a pair of FPs are required, one for each dipole, where the balun provides the out-of-phase phase difference for a pair of dipole elements within each dipole. Further, as described and depicted in Figure 13B and Figure 11 and 13A In another configuration, the antenna can use three dipoles mounted at 120° to each other, with 6 of the lobes 110 such that the antenna receives or transmits signals with a relative phase difference of 0°, 60°, 120°, 180°, 240° and 270°. Obviously, other configurations can be implemented without departing from the scope of the application.

[0191] Reference is now made to Figure 2depicts a lower perspective view 200A of a GNSS antenna according to embodiments of the application, wherein the PCB 120a is removed. Thus, Figure 2 depicts a perspective view similar to the lower perspective view 100A in Figure 1A depicts a perspective view similar to the lower perspective view 100A in depicts a lower perspective view 100A of a GNSS antenna according to embodiments of the application, wherein the PCB 120 is removed. Thus, the array of petals 110 is depicted together with a first artificial artifact 170A. Also depicted is an isolator block 240 through the bottom of which the FP is projected into the area 180. The FPs are formed on dipoles, one pair of FPs being arranged on a first circuit board dipole A 220 and another pair of FPs being arranged on a second circuit board dipole B 230. The dipole A 220 and the dipole B 230 are arranged perpendicular to each other. Also depicted are first to fourth supports 210A to 210D, wherein these supports are arranged radially within the GNSS antenna. Each of the first to fourth supports 210A to 210D is arranged between one end of the dipole A 220 and one end of the dipole B 230. Thus, the first to fourth supports 210A to 210D support additional petals 110 within the array of petals 110, the petals 110 being arranged between the petals 110 associated with the dipole A 220 and the dipole B 230.

[0192] With reference to Figure 3 depicts an upper perspective view 300 of a GNSS antenna according to embodiments of the application, wherein the array of petals 110 is removed. Thus, Figure 3 depicts a perspective view similar to the upper perspective view 100B in Figure 1B depicts a perspective view similar to the upper perspective view 100B in depicts an upper perspective view 300A of a GNSS antenna according to embodiments of the application, wherein the array of petals 110 is removed. Thus, the orthogonally arranged dipole A 220 and dipole B 230 and the first to fourth supports 210A to 210D are depicted, respectively. The isolator block 240 is in the center. From the lower perspective view 100A in Figure 1A the lower perspective view 200 in Figure 2 the upper perspective view 300A in Figure 3 it is apparent that the outer end of each of the dipole A 220, the dipole B 230 and the first to fourth supports 210A and 210D comprises a projection, said projection fitting in a slot in the PCB 120 that positions each outer end.

[0193] The middle portion of each of dipole A 220 and dipole B 230 includes an FP that similarly passes through a slot within PCB 120 in region 150 and engages a slot formed within standoff 240. The inner lower end of each of first to fourth supports 210A to 210D also engages a feature on the outer surface of standoff 240. The orientation of each of dipole A 220, dipole B 230, and first to fourth supports 210A to 210D is defined by these engagements with PCB 120, standoff 240, and support bracket 310, respectively, where the upper regions of these elements engage slots within support bracket 310. Thus, each of dipole A 220, dipole B 230, and first to fourth supports 210A to 210D are substantially perpendicular to PCB 120. It will be apparent to those skilled in the art that other mechanical means can be used to position, orient, and hold dipole A 220, dipole B 230, and first to fourth supports 210A and 210D without departing from the scope of the present application.

[0194] Reference is now made to Figure 3B FIG. 3B depicts a partial exploded assembly 300B of dipole A 220, dipole B 230, first to fourth supports 210A to 210D, and standoff 240 for a GNSS antenna according to embodiments of the present application. Apparent on standoff 240 are slots that allow for the insertion of dipole A 220 and dipole B 230 so that the FPs pass through the bottom of standoff 240 and, in the final assembly, through PCB 120. Also apparent are slots for engaging the inner lower portions of first to fourth supports 210A to 210D, respectively.

[0195] In addition to providing mechanical alignment of dipole A 220 and dipole B 230, standoff 240 also provides benefits for the performance of a GNSS antenna according to embodiments of the present application in the microwave / RF arts. As Figures 3B-6As shown, each of dipole A 220 and dipole B 230 is depicted as configured according to the above description, and as described in FIG. 13 with respect to the second electrical configuration 1300C, but transmission lines, baluns, etc. have been omitted for clarity. Thus, when assembled dipole A 220 and dipole B 230 are arranged near the point where they intersect, a pair of metallized lines (one from each of dipole A 220 and dipole B 230) run perpendicular parallel to each other, thus forming another parasitic transmission line through the intervening medium, e.g. air, where there is no mounting block 240. If the metallization is only on each side of dipole A 220 and dipole B 230, a single parasitic transmission line can be formed, while when each side of dipole A 220 and dipole B 230 is metallized, four parasitic transmission lines can be formed. If the dielectric between these parallel tracks on dipole A 220 and dipole B 230 is air, the frequencies at which these parasitic transmission lines "work" can be in the operating frequency range of the GNSS antenna, resulting in unwanted coupling, cross-talk, and loss, etc. The mounting block 240 provides a different dielectric constant for some or all of each parasitic transmission line, where the appropriate selection of material and dielectric constant of the mounting block 240 is such that these parasitic transmission lines "work" at frequencies outside the operating frequency range of the GNSS antenna.

[0196] Reference is now made to Figure 4 FIG. 4 depicts an exploded perspective view 400 of a pair of orthogonally positioned dipoles for a GNSS antenna, according to embodiments of the application.

[0197] In the exploded perspective view 400, dipole A 220 and dipole B 230 are separated vertically. Dipole A 220 has first and second dipole metallizations 410A and 410B, each forming half of a dipole. The first dipole metallization 410A is electrically coupled to a first FP 430A in the lower left center of dipole A 220, while the second dipole metallization 410B is electrically coupled to a second FP 430B in the lower right center of dipole A 220. Similarly, a third dipole metallization 420A is electrically coupled to a third FP 430C in the lower left center of dipole B 230, while a fourth dipole metallization 420B is electrically coupled to a fourth FP 430D in the lower right center of dipole B 230. The first through fourth FPs 430A-D are the FPs apparent in the middle regions 180 of the lower perspective views 100A and 200A-B of FIGS. 1 and 2, respectively. Figure 2 and 2 the FPs apparent in the middle regions 180 of the lower perspective views 100A and 200A-B of FIGS. 1 and 2, respectively. Figure 4 and Figure 4The mounting lugs 440 of the outer lower portions of the dipoles A 220 and B 230 are depicted in the exploded and disassembled perspective views 400A and 400B, respectively, in B. The mounting lugs 440 engage slots within the PCB 120 for mounting the dipoles A 220 and B 230 to the PCB 120 and define their relative orientation to within 90° of each other through the slots within the PCB 120 for mounting the dipoles A 220 and B 230, respectively.

[0198] Alternatively, in another embodiment of the present application, as described above and Figure 13B As shown in FIG. 13C, in a second electrical configuration 1300C, the dipoles can employ integrated baluns such that only one pair of FPs is required, one for each dipole. As in the described configuration, the second FP 230B and the third FP 230C can be coupled to external microwave / RF circuitry such that the first and second dipole metallizations 410A and 410B are coupled to the second FP 430B via an integrated balun (not shown for clarity) and the third and fourth dipole metallizations 420A and 420B are coupled to the third FP 430C via another integrated balun (not shown for clarity). In other embodiments of the present application, the second FP 430B can be replaced with the first FP 430A and / or the third FP 430C can be replaced with the fourth FP 430D, with integrated baluns being used.

[0199] As shown, the dipoles A 220 and B 230 have interlocking slots for assembly of the cross-dipole arrangement according to embodiments of the present application. However, in other embodiments of the present application, other assembly configurations can be used without departing from the scope of the present application to provide a pair of cross-dipoles using 2, 3, or 4 elements and other connections and assembly approaches without departing from the scope of the present application. As shown in embodiments of the present application, the profile of the upper center edges of the dipoles A 220 and B 230 include a notch for supporting a stiffener connected to a flexible circuit forming an array of petals 110, such as the support frame 310 shown and described above with respect to Figure 3 The upper edges of the dipoles A 220 and B 230 provide mechanical support for the respective petals 110 of the array of petals 110 associated therewith. In one embodiment of the present application, the array of petals 110 can be formed from a semi-flexible or flexible PCB, with the array of petals 110 being metallization- wise imprinted on the semi-flexible or flexible PCB.

[0200] By properly designing and connecting the array of petals 110 within the GNSS antenna with respect to the dipoles A 220 and B 230, then the semi-flexible or flexible PCB and thus the array of petals 110 are in mechanical contact with the upper edges of the dipoles A 220 and B 230, electromagnetic coupling between the narrowband dipoles, dipoles A 220 and B 230 is achieved, while the opposite metallized petals 110 are determined by a predetermined distance between the metallized petals 110 and the metallized dipoles printed on the dipoles, thus achieving a distributed feed network where each metallized petal has no direct connection with the external microwave / RF circuitry, for example Figure 1A the electronic device 140 is shown.

[0201] Therefore, referring to Figure 5 and Figure 6 , a first and second images 500 and 600, respectively, of a pair of dipoles for a GNSS antenna according to embodiments of the present application are depicted. Referring to the first image 500 in Figure 5 , a schematic of the dipole A 220 is depicted, where it is shown that the first dipole metallization 410A is electrically coupled with the first FP 430A at the left center lower part of the dipole A 220, while the second dipole metallization 410B is electrically coupled with the second FP 430B at the right center lower part of the dipole A 220. It is also depicted the first slot 510, which allows the assembly of the dipole A 220 with the dipole B 230, which has a corresponding second slot 520. Moreover, as described in Figure 13B respectively about the first and second electrical configurations 1300B and 1300C, the dipole A 220 can also implement the first and second dipole metallizations 410A and 410B at the other side of the dipole A 220, where the two sides are electrically connected through a plurality of vias.

[0202] Referring to the second image 600 in Figure 6 , a schematic of the dipole B 230 is depicted, where it is shown that the third dipole metallization 420A is electrically coupled with the third FP 430C at the left center lower part of the dipole B 230, while the fourth dipole metallization 420B is electrically coupled with the fourth FP 430D at the right center lower part of the dipole B 230. It is also depicted the second slot 520, which allows the assembly of the dipole B 230 with the dipole A 220, which has a corresponding first slot 510. Moreover, as described in Figure 13B respectively about the first and second electrical configurations 1300B and 1300C, the dipole B 230 can also implement the third and fourth dipole metallizations 420A and 420B at the other side of the dipole A 220, where the two sides are electrically connected through a plurality of vias.

[0203] Figure 5 the first image 500 andFigure 6 The second image, 600, represents dipoles A220 and B230, used for... Figure 13B The configuration described and depicted in the second electrical configuration 1300C, wherein each of dipole A 220 and dipole B 230 includes an integrated balun. Figure 5 The first image in the series 500 and Figure 6 In the second image 600, only the ground track is depicted; for clarity, the microstrip feed line, the first transmission line 1380A, and its electrical connection to the dipole element, i.e., pad 1395, are omitted. Therefore, refer to... Figure 5 In the first image 500, a first dipole metallization 410A is coupled to a first FP 430A via a first trace 530A, and a second dipole metallization 410B is coupled to a second FP 430A via a second trace 530B. Similarly, a third dipole metallization 420A is coupled to a third FP 430C via a third recording channel 540A, and a fourth dipole metallization 420B is coupled to a fourth FP 430D via a second recording channel 540B. For clarity, a microstrip line (not depicted) for dipole A 220 is coupled to an external microwave / RF feed at a first coupling point 550. Similarly, a microstrip line (not depicted) for dipole B 230 is coupled to an external microwave / RF feed at a second coupling point 560. In this configuration, the first FP 430A and the fourth FP 430D are connected to ground, and each of dipole A 220 and dipole B 230 is connected to a single microwave / RF signal. In this configuration, an external microwave / RF feed network supplies or receives two microwave / RF signals to the antenna comprising dipole A 220 and dipole B 230.

[0204] In another embodiment of the invention, dipole A 220 and dipole B 230 do not include an integrated balun. Therefore, the first recording channel 530A and the second recording channel 530B can be symmetrical mirror images, and each recording channel 530A and the second recording channel 530B is connected to its respective first and second FPs 430A and 430B, such that a pair of microwave / RF signals are coupled to or from dipole A 220. Similarly, the third recording channel 530A and the fourth recording channel 530B can be symmetrical mirror images, and each is connected to its respective third and fourth FPs 430C and 430D, such that a pair of microwave / RF signals are coupled to or from dipole B 230. In this configuration, an external microwave / RF feed network provides or receives four microwave / RF signals to or from the antenna including dipole A 220 and dipole B 230.

[0205] like Figure 5As shown in the first image 500, the lower edge of the dipole A 220 includes a first FP 430A and a second FP 430B towards the center, and a mounting lug 440 at the outer edge. The upper edge defines a central region for supporting a stiffener (e.g., support frame 310) and the array of petals 110, while the outer upper edge defines a curved surface to which the array of petals 110 conforms when attached. Similarly, as shown in the second image 600, the lower edge of the dipole B 230 includes a third FP 430C and a fourth FP 430D towards the center, and a mounting lug 440 at the outer edge. The upper edge defines a central region for supporting a stiffener (e.g., support frame 310) and the array of petals 110, while the outer upper edge defines a curved surface to which the array of petals 110 conforms when attached. Figure 6 As shown in the first image 500, the lower edge of the dipole A 220 includes a first FP 430A and a second FP 430B towards the center, and a mounting lug 440 at the outer edge. The upper edge defines a central region for supporting a stiffener (e.g., support frame 310) and the array of petals 110, while the outer upper edge defines a curved surface to which the array of petals 110 conforms when attached. Similarly, as shown in the second image 600, the lower edge of the dipole B 230 includes a third FP 430C and a fourth FP 430D towards the center, and a mounting lug 440 at the outer edge. The upper edge defines a central region for supporting a stiffener (e.g., support frame 310) and the array of petals 110, while the outer upper edge defines a curved surface to which the array of petals 110 conforms when attached.

[0206] As described above, the first dipole A 220 in the pair of crossed dipoles is formed by first and second dipole metallizations 410A and 410B, respectively, while the second dipole B 230 is formed by third and fourth dipole metallizations 420A and 420B, respectively. Considering an embodiment of the present application in which the dipoles A 220 and B 230 are formed on a dipole PCB, each dipole thus includes a pair of centrally disposed vertical metal traces that connect to the dipole elements at the inner ends of each of the dipole metallization traces. The dipole PCB can have substantially the same thickness as the connecting slots within the PCB 120 to allow for accurate mounting of the dipoles with respect to a ground plane formed within or on the PCB 120. Optionally, each dipole PCB can include a duplicate of the same balun.

[0207] As described above, the upper edges of the dipoles A 220 and B 230 define a predetermined distance between the metallized petals 110 and the metallized dipoles printed on the dipoles, thereby implementing a distributed feed network between the dipoles and the petals 110. In this manner, the petals 110 do not have a direct connection to the FPs and the microwave / RF circuitry. However, from Figure 5 and Figure 6It is apparent that in embodiments of the present application the dipole varies radially in geometry, the dipole metallization varies radially from the separation of the petal 110 associated with it, or varies with the elevation angle from different angles. This petal-dipole separation as a function of elevation angle depends on the GNSS antenna design, such that the upper edge of the dipole element is defined by the petal geometry and vice versa. It is also apparent that the length of the dipole element between the inner edge of the dipole A 220 and dipole B 230 and the outer point of the lower outer region of each dipole A 220 and dipole 230 is determined by the requirement that the dipole element is electrically l / 4 at the center frequency of the GNSS antenna. The inventors have also determined that while meeting the requirement and implementing the associated petal 110, the sensitivity of the structural impedance is not very sensitive to the distance between the petal 110 and the dipole element towards the center of the dipole, allowing increased flexibility in the overall design of the geometry of the petal 110 relative to the dipole. Thus, as shown in Figure 5 , the distance of the upper edge of the dipole element relative to the upper edge of the PCB forming them is different. However, in other embodiments of the present application this separation between the dipole metallization and the petal 110 can be constant.

[0208] Reference is now made to Figure 7A , depicting a perspective view 700A of a petal array 110 (i.e. petal assembly) for a GNSS antenna, according to embodiments of the present application. As shown, the petal array 110 includes 8 petals 110, which are metallized areas on an insulating former 710. At the lower end of each petal 110 is a pair of lugs 130, as described and depicted in Figure 1A , for mounting and connecting the petal 110 to the PCB 120, which are not described for clarity. In embodiments of the present application, the metallization on the lugs 130 is solderable to the PCB 120. The metallization on the lugs 130 is electrically isolated from the metallization forming the petal 110. In one embodiment of the present application, the metallization on the lugs 130 is connected to the ground layer of the PCB 120. It is apparent that in other embodiments of the present application the lower end of the petal 110 can be connected to the PCB 120 by other means, including mechanical retention, mechanical connection or by a material such as resin, glue or epoxy. In other embodiments of the present application, the petal 110 can be mechanically retained in place by one or more additional elements mounted externally to the petal 110, the petal 110 being connected to the PCB 120 and / or to the dipole A 220 / dipole B 230 and / or to the first to fourth supports 210A to 210D, respectively, without the use of protrusions such as the lugs 130.

[0209] Reference is now made to Figure 7B, depicts a planar perspective schematic 700B and a photograph 700C of a petal array for a GNSS antenna according to embodiments of the present application. Referring to the schematic 700B, an array of 8 petals 710 is depicted. In this case, the tips of the petals 710 form lugs 720 with the tips of the middle petals. The photograph 700C depicts a photograph of an array of petals 730 according to embodiments of the present application, which do not have end lugs, as the petals 730 are held mechanically, for example, by a circular protrusion above the PCB 120, which the petals 730 push against when they are bent and mounted in the center.

[0210] Reference is now made to Figure 7C , depicts a planar schematic of an array of petals 740 for a GNSS antenna according to embodiments of the present application, in an assembled view 700D and an unassembled view 700E. As shown in the assembled view 700D, each petal 740 has a lug 750 and a support frame 760 at its distal end in the center of the array of petals 740. In the unassembled view 700E, the array 700 at that time comprises an array of petals 740 for a GNSS antenna, and is depicted as being separated from the support frame 760. In other embodiments of the present application, the support frame 760 can be omitted. The support frame 760 can provide a support frame 310 as shown in Figure 7C , which engages the upper central portion of the dipole PCB and / or support. Optionally, in other embodiments of the present application, the support frame 760 can be integrated as part of the array of petals. Figure 3

[0211] When using a central support 760, as shown in Figure 3 , with the support 310, the shape of the upper edges of the dipole A 220, dipole B 230 and the first to fourth supports 210A to 210D can include notches, respectively, to accommodate the central support 760 connected to the semi-flexible PCB forming the array 700 on which the petals 740 are formed. Alternatively, the central support 760 can include notches to accommodate the upper edges of the dipole A 220, dipole B 230 and the first to fourth supports 210A to 210D, respectively. The central support 760 can be made of a low-loss dielectric substrate, which has the same shape and size as the central area of the upper portion of the dipole assembly comprising the dipole A 220, dipole B 230 and the first to fourth supports 210A to 210D, respectively. As shown in Figure 7C ​As shown in center unassembled view 700E, center support 760 is an octagonal substrate, for example formed of fiberglass reinforced epoxy laminate material, which is attached using an adhesive to the semi-flexible PCB forming array 700. The combination of the metallized petal assemblies, array 700 and center support 760 results in a sub-assembly consisting of a rigid center region and semi-flexible petals, with each metallized petal being supported by the dipoles of dipole A 220 and dipole B 230 and first through fourth supports 210A-210D, respectively. It is readily apparent that in other embodiments of the present application, the geometry of support frame 760 can vary, including for example, a circular shape.

[0212] In Figures 1A-7C , an array of petals 110 is depicted, for example petal assembly 800, where petals 110 are metallized layers on flexible or rigid (formable) substrates. While this provides a design that is easy to manufacture the array of petals 110 and assemble the GNSS antenna, it is readily apparent that in other embodiments of the present application, petals 110 can be manufactured discretely and assembled with other components to form a GNSS antenna.

[0213] Referring now to Figure 8 , a photograph 800 of a GNSS antenna according to an embodiment of the present application is depicted, which uses 8 petals in the array of petals. A metallized disc 910 is arranged in the upper center of the array of petals, forming a pattern on the substrate of the array of petal elements. Disc 910 is centered between each pair of opposing petal elements, and is the common center of all opposing pairs of petals. By virtue of the presence of the opposite voltage at the narrow petal tips of petal elements 110, metallized disc 910 provides a controlled capacitance to virtual ground. In Figure 1B 、 7A and 7C-7D, the disc 910 can also be seen in the views of the GNSS antenna and array of petals 110, respectively, but is not explicitly identified in the description of these figures.

[0214] Referring to FIG. 10, a photograph of a GNSS antenna according to an embodiment of the present application is depicted, where 4 petals 110 are used in the array of petals. This is the minimum configuration of petals 110 for a GNSS antenna employing a pair of orthogonal dipoles.

[0215] Referring now to Figure 10A and 10BSchematic diagram 1000A and photograph 1000B depict a planar perspective view of a wing array for a GNSS antenna according to an embodiment of the present invention employing four winglets. In schematic diagram 1000A, the winglets 110 are clearly visible together with the lugs 130. In schematic diagram 1000A, metallization is depicted as the shaded areas forming the winglets 110; therefore, it is clear that there is no overall pattern of metallization on the lugs 130, but rather discrete pads 1010. Photograph 1000B depicts a four-lobed array 110, wherein there are no labels between the distal ends of the winglets 110 and the center of the array.

[0216] refer to Figure 11 The diagram shows a planar perspective view of a pair of winglets according to an embodiment of the present invention, the pair of winglets being used for an antenna using a pair of winglets 110, wherein, as in schematic diagram 1000A, each winglet 110 has a pair of lugs 130, the distal end of which is provided with a pad 1010. Figure 11 The pair of lobes 110 depicted in the figure are, for example, the pair of lobes depicted in cross-sectional view 1300A of Figure 13, as described above, coupled to a single dipole.

[0217] Now for reference Figure 12 A schematic diagram 1200 depicts an alternative configuration of the wing 1310 and tag 130 used within a GNSS antenna according to an embodiment of the present invention. Thus, as shown, the piece 130 is metallized with a first metallization 1320 instead of discretely metallizing each piece. The first metallization 1320 is now continuous at the distal end of the wing 1310. However, the first metallization 1320 is electrically isolated from a second metallization 1330, which, together with the carrier 1310, provides the wing, on which the first and second metallizations 1320 and 1330 are formed. Furthermore, as shown, a lug 130 extends through an opening within the PCB 120, where the first metallization 1320 will be connected to the ground plane of the PCB 120.

[0218] exist Figure 1A In embodiments of the invention up to 13, the winglets 110 are primarily described and depicted as being located on a carrier / substrate (hereinafter referred to as the former), wherein the winglets 110 are uniformly distributed around the former. The former is described as forming essentially a truncated hemisphere. In other embodiments of the invention, the former may be designed and formed to provide different physical geometries, such as a conical surface around which the winglets 110 are distributed. In other embodiments of the invention, the former may be designed and formed to provide winglets 110 uniformly distributed around a polygonal surface, and to form an antenna on the polygonal surface. Such a polygonal surface may have 4, 5, 6, 7, 8, or other numbers of sides, although generally more sides result in a lower angular transition, and thus stress and / or fatigue.

[0219] With respect to Figures 1A-15 Embodiments of the invention described and depicted employ a PCB 120. The PCB can be fabricated on a low loss substrate such as a glass reinforced epoxy laminate material, a glass ceramic composite laminate or a ceramic composite laminate. The PCB substate selection provides the necessary performance of the microwave / RF elements and circuits of the electronics 140 and tracks to the coupling of the dipoles A 220 and B 230. The GNSS antenna frequencies can limit the PCB size. In one embodiment of the invention, the PCB 120 is circular with a diameter of about 110 mm with one or more metallized layers. Features such as ground vias and mounting holes can be formed in the PCB 120, for example for the lugs 130. Mounting holes 160 or mounting slots are also disposed within the PCB 120 for mounting the GNSS antenna to a choke, antenna support, etc. The ground plane of the GNSS antenna within the embodiment PCB 120 can be fabricated within a two or more layer PCB 120 with the surface proximate to the mounted antenna structure completely covered with metallization to provide a reflecting microwave surface for the dipole and petals disposed thereon. This metallization acts as a reflecting ground plane commonly used in GNSS antennas to increase the radiation gain above the antenna elements while decreasing the radiation gain below the ground plane.

[0220] With respect to Figure 1A In the embodiments of the invention described and depicted with respect to Figures 1 through 13, each petal is formed by a pattern of metallization on a semi-flexible substrate such as a glass reinforced epoxy laminate material, a glass ceramic composite laminate or a ceramic composite laminate, the result of which is given in Section 4, for example, a thickness of less than 0.2 mm (0.008”). Each metallized petal 110 is a two-dimensional shape with a wider outer end and a narrower center end, the center axis being longer than the wider end, the width between the wider end and the narrower end tapering. One pair of petals 110 in each pair of opposing petals 110 is comprised of a first petal 110 and a second petal 110, co-linear with the first petal 110, the same size, the proximal end of the first petal 110 and the second petal 110 being the narrower end, the midpoint between the first petal 110 and the second petal 110 being mirrored about an axis, located on an extended common axis defined as the geometric antenna center.

[0221] In embodiments of the invention, the position of the plurality of pairs of metallized petals is such that the midpoint of each pair of petals is located at the antenna center, the relative angle of rotation between adjacent pairs of petals is equal to all pairs of petals, equal to 360 degrees divided by 2N, where N is the number of pairs of metallized petals implemented. For a linear antenna, the minimum number of pairs of metallization is 1, for a circularly polarized antenna, the minimum number of pairs of metallization is 2, while the maximum number is limited by practical considerations. In the above described embodiments, N = 2 or 4.

[0222] InFigure 1A In the embodiments of the application described and depicted in Figs. 1 to 13, each petal is formed by the upper edges of the dipole A 220 and the dipole B 230, forming a surface that defines a substantially hemispherical surface, the consequences of which are given in section 4. The upper surfaces of the first to fourth supports 210A to 210D respectively define surfaces similar to the dipoles A 220 and B 230. However, it is clear that in other embodiments of the application, the surfaces defined by these surfaces have different shapes, although the performance of the GNSS antenna can be different.

[0223] In the embodiments of the application described and depicted above, the mechanical assembly not only orients a pair of orthogonal dipoles relative to each other, but also orients them perpendicularly to the plane of the PCB. Thus, if we consider that the dipole A 220 is aligned with the X axis, it is positioned in the X-Z plane and the dipole B 230 is aligned / positioned relative to the Y-Z plane.

[0224] In relation to the embodiments of the application described and depicted in Figs. 1 to 13, the dipoles A 220 and B 230 are formed by the upper edges of the first to fourth supports 210A to 210D, respectively. In the embodiments of the application described and depicted in Figs. 1 to 13, the dipoles A 220 and B 230 are formed by the upper edges of the first to fourth supports 210A to 210D, respectively. Figures 1A-7B In the embodiments of the application described and depicted in Figs. 1 to 13, each petal 110 has a lug 130 at its distal end, away from the centre of the antenna. In the embodiments of the application described and depicted, these are metallized, so that in the assembled GNSS antenna, by this metallization, the semi-flexible PCB is mounted to the dipole structure and the ground plane of the PCB 120. As shown in Fig. 6, the metallized lugs are connected to thin metallized tracks parallel to the wider edges of the metallized petals on the semi-flexible PCB 700. This thin metallized track is electrically isolated from the metallized petals by a narrow non-metallized spacing. Figure 12

[0225] The separation of the petals and the ground plane is important in several respects. First, the currents associated with the transmitted or received radio frequency waves are mainly conducted along the edges of the metallized petals, thus forming a microwave slot between the ground plane and the petals. As a transmission line, the slot guides the radio frequency waves, producing a zero current at the centre of the wider edges and effectively reducing the low frequency response. Second, the capacitance between the ground plane and the petals is mainly determined by the uncalculated gap, which has a precisely defined size due to the precision of the PCB manufacturing process, allowing a precisely defined capacitance. Although other mechanical assembly methods can be employed to connect / position the petals 110, these must take into account this capacitance and its variations within its design and manufacturing tolerances.

[0226] ​Third, the lack of calculation of changes in gap size and transmission line impedance provides a convenient method for adjusting the effective patch length of the GNSS antenna at lower frequencies. Therefore, the gap can be established based on tuning to a frequency to be applied below a predetermined frequency. Fourth, the reduced capacitance (increased reactance) at the bottom of the wing effectively increases the wing's natural frequency as a monopole, thereby increasing the frequency of any common-mode (monopole) resonance well beyond the upper receiver band edge. Finally, the non-metallic gap effectively reduces the coupling of ground plane current to the wing, at least to some extent.

[0227] In an embodiment of the invention, all lobes 110 are simultaneously formed by patterning the metallization layer of a semi-flexible PCB. The external dimensions of the semi-flexible PCB can then be larger than the slot of the assembly lug 130, so that the semi-flexible PCB, when assembled on two dipoles (dipole A 220 and dipole B 230) and fixed to the ground plane of PCB 120, conforms to the shape of the upper surfaces of the two dipole PCBs. Therefore, these can define a hemispherical dome. Thus, during assembly, each metallized lobe 110 bends from its wider end, fixed to the ground plane of PCB 120, towards its narrower end, located at a point above the antenna center, the height of which is predetermined by the structural dimensions of the GNSS antenna assembly.

[0228] The central region of the semi-flexible substrate PCB of the dual-metallized wing pair is concentric with the antenna center. In the case of two pairs of metallized winglets, the central region may be an octagon with regular octagonal dimensions, approximately intersecting the plane. The dimensions of the central region may match the dimensions of the reinforcement (e.g., support frame 310). In embodiments of the invention employing four winglets 110, the first to fourth supports 210A to 210D may optionally be removed, especially if the semi-flexible PCB is present only where the winglets 110 are implemented. In the case of using four pairs of metallized winglets, for example in Figures 1A-9 In the illustrated embodiment, the first to fourth supports 210A to 210D respectively ensure that the lobes 110 arranged between the lobes 110 associated with the pair of dipoles have the same surface profile.

[0229] In embodiments of the present invention, such as Figures 1A-2 As shown in B, 7A-7B, and 7D-10, the metallization of the wing 110 is a slotted pattern, with these slots perpendicular to the ground plane of the GNSS antenna within the assembled GNSS antenna. This has two advantages:

[0230] Together with the transmission line consisting of the metallized lobes and the non-metallized gap between the ground plane, these slots are induced, acting as stubs, thus effectively reducing the wavefront and further lowering the low end of the frequency response; and

[0231] The increased impedance at the wider end of the flap can effectively reduce the coupling between the metallized flap and the ground plane.

[0232] Section 3: Working Principle of Dipole-Fed Antenna Elements and Systems

[0233] As described in Section 1, the inventors' design goal was to create a high-precision GNSS antenna with wide bandwidth, good AR (Average Reception) and very tight phase center variation, and improved performance in receiving satellite signals at low elevation angles. This is particularly important for the reception of L-band correction signals, which are expected to be incident at elevation angles of 10 to 50 degrees above the horizon.

[0234] The core of the design method developed by the inventors is to eliminate feed current within the antenna ground plane, such as the ground plane in a PCB 120. This ground plane reflects the transmitted signal, thus achieving higher gain at heights above the ground plane compared to antennas without a ground plane. Since another objective for most antennas is to minimize footprint, the diameter (typically circular) of the ground plane is usually close to 1 / 2 at the operating frequencies of GNSS antennas. Therefore, the ground plane can easily couple to other antenna elements, leading to performance degradation. Thus, the design method of eliminating any current in the ground plane reduces such coupling effects and performance degradation.

[0235] In existing technology, the Dorne Margolin (DM) antenna has been used in GPS reference stations for decades (typically in choke coil antennas). The DM antenna offers higher gain than other commercial GNSS antennas (typically -5 dBic or less) at low elevation angles (approximately -3 dBic in the horizontal direction) and exhibits fairly good phase center stability in a compact design. The DM antenna structure consists of two pairs of orthogonal short dipoles above a ground plane, with the feed located at the midpoint of the dipoles, as shown below. Figure 14 The first image 1400A in A is shown. As shown, the first dipole 1410 and its feed 1415, and the second dipole 1420 and its associated feed 1425 are arranged above the ground plane 1430.

[0236] Therefore, refer to Figure 14The second image 1400B in B, which can take into account the antenna from the ground plane image, replaces the ground plane 1430 with the image of dipoles. Thus, the third dipole 1440 represents the image of the first dipole 1410A and the fourth dipole 1450 represents the image of the second dipole 1420. Thus, when the first and second dipoles 1410 and 1420 are driven, the resulting antenna structure acts as a large uniform current circular ring, which is structurally similar to the structure of an Alford circular antenna. However, the disadvantage of DM antennas is the complexity of the feed network, the high losses, the high manufacturing cost, which affects the repeatability and reliability. In addition, the AR at zenith is critical (up to 1.5 dB), further reduced at the horizon to 7 dB, a factor that becomes less important in the choke configuration of the most commonly used DM antennas.

[0237] Therefore, the inventors, after significant research and development, established the design method outlined in Section 2 for a GNSS antenna according to embodiments of the present application, as Figure 15 A. Thus, the GNSS antenna consists of butterfly-shaped radiator elements (petals) arranged on a circular ground plane. The petals are coupled to a distributed feed network, which includes a pair of low-loss crossed dipoles, namely dipole A 220 and dipole B 230, as described in Figures 2-6 B and 8, between the petals and the ground plane. The relationship between the petals and the associated feed system provides maximum current at the curvature of the petals rather than at the center of the antenna. This is evident in the simulation results shown in Figure 15 where the current is maximum towards the middle of each edge of each petal. Thus, the resulting current distribution is similar to the current distribution within the DM antenna elements. This increases the gain at low elevation angles, greatly improving the link margin for low-elevation GNSS and L-band satellites.

[0238] The inventors have determined that by optimizing the dimensions of the petals, such as their height, width, and angle with respect to the ground plane, the circular polarization of the antenna at low elevation angles can be significantly improved. These geometric adjustments can address the problem of asymmetry between the antenna radiation patterns E and H planes, which would normally reduce the AR at low elevation angles. According to the simulation results, the inventors determined that the bowtie geometry of the heat sinks (petals) and their coupling with the feed network can improve the impedance and AR bandwidth of the GNSS antenna. In this way, the inventors established a wideband, low-loss antenna covering the entire GNSS frequency from 1150 MHz to 1610 MHz. Exemplary performance, more details in Section 4, namely the matching loss of the feed network is lower than 0.3 dB, the AR at zenith remains around 0.5 dB, and the AR at the horizon is generally lower than 3 dB over the entire GNSS frequency range.

[0239] Reference is made to Figures 9-10BThe GNSS antenna has 4 lobes, while in Figures 1A-2 B, 7A-9 and 15A have 8 lobes. During the development of the GNSS antenna, the inventors determined that increasing the number of lobes improves symmetry, but at the expense of complexity. Therefore, Figures 9-10B The exemplary embodiments of the present invention shown herein employ a minimum of 4, while Figures 1A-2 The embodiments in B, 7A-9 and 15A employ a minimum of 4, as this is the balance struck between improved symmetry and feed complexity relative to 4 lobes.

[0240] As mentioned above and below, the GNSS antenna according to the embodiments of the present invention receives / radiates RF signals by electromagnetic radiation generated by currents induced / driven into pairs of diametrically opposed "lobes" arranged in a piecewise linear approximation above a metallic ground plane. The received / radiated signals from the GNSS antenna are coupled from lobe pair to lobe pair by dipoles coupled to a microwave / radio frequency feed network.

[0241] The GNSS antenna according to the embodiments of the present invention employs a pair of such dipoles arranged orthogonally to each other and with high electromagnetic isolation between each other. If signals of the same frequency but with a 90 degree phase difference ("phase quadrature") are applied to the orthogonally electrically isolated antennas, the resulting radiation is circular, as the two signals can be considered independent, except to say that the resulting radiated signal is a vector sum of the radiated electric vectors that is a vector rotating in space.

[0242] Each pair of opposing lobe structures exhibits two modes of operation in the frequency band of interest. The first mode is the desired mode, in which the currents in each opposing lobe flow in phase, so the voltage generated across each lobe is also in phase, and thus the voltage is anti-phase at the ends of the lobe pair, the maximum electromagnetic field between the narrow ends of the antenna center is generated due to the low impedance of the wider ends of the lobes caused by the image / capacitance near the ground plane. When the currents flow in the same direction in each lobe, a magnetic field is generated, or, in response to a magnetic field orthogonal to the plane of the opposing lobe pair, the currents are induced in each lobe in the same direction, and the resulting wave is phase reflected by the ground plane.

[0243] The second movement is an unwanted mode, a form of cavity or monopole resonance in which the entire cavity or monopole assembly exhibits lambda / 4 resonance. In this mode, the voltages generated at the "top" of the monopole are in phase, so there is no potential difference between the narrow ends of the center lobe. In this specification, the specific considerations of the resonance mode are not discussed, as the frequency of the resonance mode can be moved to higher frequencies outside the relevant frequency band by parameter adjustment of the GNSS antenna.

[0244] Back Figure 14 B, each pair of opposite lobes can be considered as half of the Alford loop structure, in the first mode, the current in each opposite lobe flows in phase ( Figure 14 The same applies to the currents in the dipole pairs, including the first dipole 1410 and the second dipole 1420, in B. Therefore, by combining the ground plane and the mirror image of these currents, an effective Alfred loop is established.

[0245] Now consider a GNSS antenna according to an embodiment of the invention, having orthogonal first and second pairs of opposing winglets. A plane wave is then incident on the GNSS antenna at the horizon, such that the Bonting vector aligned with the axis of the first pair of opposing winglets (e.g., an electromagnetic field aligned with the vertical E-field and the horizontal H-field) will induce a current in the first pair of opposing winglets (orthogonal to the H-field), and the electromagnetic wave aligned with the horizontal E-field and the vertical H-field will generate an electromagnetic field in the second pair of opposing winglets (parallel to the E-field). This structure is advantageous for a low axial ratio because the orthogonal fields induce / generate a potential balanced signal in the orthogonal pair of winglets.

[0246] In the prior art, the simplest way to couple a feed circuit to a pair of opposing lobes is through direct electrical contact with each lobe. However, the direct-connection feed impedance for each metallized lobe varies from a low value near the edge of the ground plane at the wider end to an extremely high value near the center of the antenna at the narrower end. The feed impedance at the wider end of the lobe is low, similar to that of a monopole (approximately 25 ohms), and is further reduced by the current generated by the reflection image of the monopole on the ground plane. However, this impedance can be matched, making a direct feed to the wider end of each lobe both electrically and mechanically convenient.

[0247] However, when the feed connection is close to the edge of the ground plane, the feed loop current is also directly injected into the ground plane. At the desired frequency, the diameter of the ground plane is close to λ / 2, and the drive current flowing in the ground plane causes the ground plane itself to radiate, which severely interferes with and reduces the desired radiation characteristics. Measurements and simulations conducted by the inventors confirm that the ground return current associated with the "monopolar" flap feed results in poor axis ratio, especially at low elevation angles.

[0248] Alternatively, the direct connection at the center of the structure, where each flap is fed at the narrower end, has high impedance characteristics, which are difficult to match.

[0249] The GNSS antenna according to embodiments of the present application avoids these difficulties associated with direct electrical connections to the feed circuit by using a pair of dipoles (narrowband dipoles) that form an X-Y axis around the center point of the ground plane, for example as part of or separate from the PCB 120. A pair of dipoles, dipole A 220 and dipole B 230, are disposed above the ground plane of the PCB and coupled to the feed circuit. Above the pair of orthogonally disposed dipoles are a plurality of lobe pairs that are arranged such that the pair of dipoles is aligned along the centerline of each of the plurality of lobe pairs. The plurality of lobe pairs are circularly arranged around a z-axis that is orthogonal to the plane formed by the ground plane. The z-axis passes through the center of the ground plane. The plurality of lobe pairs are arranged such that the midpoint of each lobe pair, i.e. the midpoint between the metallized lobes, is precisely at the antenna center at the intersection of the pair of dipoles. The outer ends of each of the plurality of lobe pairs are fixed, for example to the outer circumference of the ground plane.

[0250] Thus, the GNSS antenna according to embodiments comprises a plurality of components:

[0251] • a substantially circular ground plane PCB serving as a reflecting ground plane;

[0252] • a pair of dipoles mounted perpendicular to the ground plane;

[0253] • a plurality of lobe pairs arranged above the pair of dipoles and the ground plane;

[0254] • a feed network consisting of one hybrid and two balun transformers to produce a pair of phase quadrature anti-mode signals.

[0255] The plurality of lobe pairs are arranged as a substantially hemispherical dome array of opposite metallized lobe pairs. They can be mounted on the ground plane near the outer circumference of the ground plane. A distributed feed network couples the opposite metallized lobe pairs to the circuit and provides a progressive opposite phase shift to enable the GNSS antenna to work in circular polarization.

[0256] Thus, the inventors have established an innovative wideband antenna structure comprising a narrowband dipole electromagnetically coupled to a symmetrically arranged metallized lobe on a far- field metallized ground plane, a symmetric pair of feed signals connected to a dipole feed connection at the center of the dipole, wherein the innovative wideband antenna structure provides wideband return loss and impedance at the dipole feed connection comparable to the narrowband return loss of a dipole only, wherein the metallized lobe provides a wideband lossy matching feed network to improve the radiation efficiency of the combined structure.

[0257] Therefore, the inventors have established an innovative broadband antenna structure comprising a dipole electromagnetically coupled to a symmetrical arrangement of metallized petals arranged in the center of a distally metallized ground plane, a symmetrical pair of feed signals connected to a dipole feed connection in the center of the dipole, further connected to a feed connection confined to the center of the ground plane, whereby the local current maximum in the antenna radiating element is shifted from the center of the dipole, and the ground plane is essentially free of dipole feed loop currents in the case of the dipole and the symmetrical arrangement of metallized petals arranged above the ground plane.

[0258] Therefore, the inventors have established an innovative broadband antenna structure comprising a narrowband dipole electromagnetically coupled to a symmetrical arrangement of metallized petals arranged in the center of a distally metallized ground plane, a symmetrical pair of feed signals connected to a dipole feed connection in the center of the dipole, wherein the local current maximum in the antenna radiating element is shifted from the center of the dipole, and a turning point of the current magnitude in the combined radiating element of the dipole and the symmetrical arrangement of metallized petals occurs in the center of the dipole.

[0259] Therefore, the inventors have established an innovative broadband antenna structure comprising a narrowband dipole electromagnetically coupled to a symmetrical arrangement of metallized petals arranged in the center of a distally metallized ground plane, a symmetrical pair of feed signals connected to a dipole feed connection in the center of the dipole, wherein the symmetrical arrangement of metallized petals extends the bandwidth of the antenna structure to more than the bandwidth of the narrowband dipole.

[0260] Section 4: Performance of the dipole-fed antenna element and system

[0261] The inventors describe the above antenna requirements, construction concepts and design principles in sections 1 to 3, respectively. Therefore, in this section, results for a GNSS antenna according to an exemplary embodiment of the present application are given. The GNSS antenna is as described in Figure 15 A first plot 1500 is shown in Fig.

[0262] 4.1 Radiation pattern and roll-off

[0263] The measured radiation patterns of the exemplary GNSS antenna are shown in Figure 16 and 17 These are:

[0264] • the first plot 1600A in Fig. Figure 16

[0265] • the second plot 1600B in Fig. Figure 16 ​the second graph 1600B in FIG. 16A is for GPS L2 (1.215-1.2396 GHz);

[0266] · Figure 17 the third graph 1600C in FIG. 16A is for Galileo E6 (1.260-1.300 GHz); and

[0267] · Figure 17 the fourth graph 1600D in FIG. 16A is for GPS L1 (1.563-1.587 GHz).

[0268] In FIGS. 16A and 16B, Figure 16 and Figure 17 the radiation patterns are normalized to show the RHCP and LHCP gain at 60 azimuth angles separated by three degrees. It can be seen that the LHCP signal is significantly suppressed in the upper hemisphere at all GNSS frequencies. The difference between the RHCP gain and the LHCP gain ranges from 31 dB to 43 dB, which ensures excellent discrimination between the signals. Furthermore, for other upper hemisphere elevation angles, the LHCP signal is 22 dB below the maximum RHCP gain, from 1200 MHz to 1580 MHz, and even 28 dB below the maximum RHCP gain. As can be seen from the results given below, the constant amplitude response to a particular elevation angle signal results in an improvement in the variation of the phase center, regardless of the azimuth angle.

[0269] Reference is now made to Figure 18 FIG. 16C, which depicts a comparison of a GNSS antenna according to embodiments of the present application (GNSS application) with six commercial Rohde & Schwarz prior art GNSS antennas for the same applications (GNSS 1 to GNSS 6). It is thus apparent that the GNSS antenna according to embodiments of the present application has a much lower roll-off than the prior art antennas. As shown in Figure 18 FIG. 16D, the amplitude attenuation from the boresight (zenith) to the horizon in all frequency bands for the GNSS antenna according to embodiments of the present application is between 6.5-8 dB.

[0270] However, high gain at low elevation (low roll-off) makes the antenna more susceptible to multipath interference. The multipath signals are primarily late LHCP and RHCP. If they arrive at high elevation, there is no problem as the AR of the antenna is low at these angles and hence the reception of multipath signals will be minimum. However, in conventional antennas, low elevation multipath degrades the observations due to poor AR performance and low UDR. At lower elevation angles, the GNSS antenna according to embodiments of the present application provides improved AR performance and good UDR, which significantly reduces the multipath interference. Therefore, the inventors also measured the GNSS antenna according to embodiments of the present application and 6 commercial Roamer prior art GNSS antennas in a high multipath environment. The GNSS antenna according to embodiments of the present application produces a phase noise of about 6mm to 10mm at 5° elevation for all GNSS frequencies. While the other prior art GNSS antennas perform similarly, they have a higher roll-off and hence have lower gain at the horizon. Therefore, the GNSS antenna according to embodiments of the present application provides a stronger signal at low elevation and improves the multipath rejection performance compared to the prior art antennas.

[0271] 4.2 Antenna Gain and Efficiency:

[0272] Reference Figure 19 depicts the right hand circular polarization (RHCP) gain of the GNSS antenna according to embodiments of the present application at zenith and 10° elevation for all GNSS frequencies. These measurements show that the gain of the antenna at zenith ranges from 4.1 dBic at 1160 MHz to 3.6 dBic at 1610 MHz. The antenna gain at 10° elevation varies from -1.45 dBic to -2.2 dBic, which is maximum within the frequency range used for broadcast L-band corrections (1539 MHz to 1559 MHz). Figure 20 The radiation efficiency (loss in percentage and dB) of the GNSS antenna according to embodiments of the present application is described, from which it is evident that the radiation efficiency is between 70% to 89% across the entire bandwidth.

[0273] This corresponds to an intrinsic (“hidden”) loss of only 0.6 dB to 1.5 dB, including copper loss, feed line, matching circuit, and 90-degree hybrid coupler loss. This performance is a significant improvement over other alternative antenna element geometries, such as helical antennas, which exhibit close to 4 dB of intrinsic efficiency loss at lower GNSS frequencies. A G / T of -25 dB / K at 10 degrees elevation was measured by integrating a wideband pre-filtered low noise amplifier (LNA).

[0274] 4.3 Axial Ratio

[0275] Figure 21 The AR values of the GNSS antenna according to embodiments of the present application at different elevation angles are shown. AsFigure 21 As shown, the GNSS antenna according to embodiments of the present application has good AR performance over all GNSS bands and all elevation angles, and does not exceed 3.5 dB. It is well known that low AR improves the antenna's ability to reject LHCP signals caused by reflections off nearby objects. Therefore, the GNSS antenna according to embodiments of the present application is much less sensitive to multipath interference. Furthermore, referring to Figure 22 The AR performance of the GNSS antenna according to embodiments of the present application over the horizon was compared to six commercial Roamer GNSS state-of-the-art antennas. It is evident from these results that the GNSS antenna according to embodiments of the present application has the lowest AR among these antennas. The lowest AR among these competing antennas can be comparable to the worst AR in the GNSS antenna according to embodiments of the present application, but for commercial GNSS antennas, the AR is typically significantly significantly significantly higher relative to the GNSS antenna according to embodiments of the present application.

[0276] 4.4 Phase center variation

[0277] To estimate the PCV from the measured radiation pattern, a MATLAB code was implemented, where the results of the analysis are shown in Figure 23 As shown, Figure 23 The maximum PCV of the GNSS antenna according to embodiments of the present application relative to six commercial Roamer antennas for the four common GNSS frequencies is depicted. It is evident from Figure 23 the results that the maximum total PCV of the GNSS antenna according to embodiments of the present application is less than 2.9 mm in all bands, describing the results for GPS LI, GPS L2, GPS L5 and Galileo E6. Furthermore, the PCV of the GNSS antenna according to embodiments of the present application does not vary significantly with frequency.

[0278] 4.4 Low noise amplifier design

[0279] For signals with marginal power flux density, the achievable best carrier-to-noise ratio (CNR or C / N) is limited by the efficiency, gain, and overall receiver noise figure of each antenna element. This can be quantified by the ratio parameter G / T, which is typically determined by the noise figure of the input LNA within the receiver microwave / RF electronics. In an exemplary LNA amplifier design according to an embodiment of the present application, the received signals from a GNSS antenna according to an embodiment of the present application are split into two frequency bands by a duplexer connected directly to the antenna terminals, one frequency band comprising the lower GNSS frequencies (from 1160 MHz to 1300 MHz) and the other frequency band comprising the higher GNSS frequencies (from 1539 MHz to 1610 MHz). Each frequency band is then pre-filtered. It is therefore apparent to those skilled in the art that this is where the inherent advantage of high gain and high efficiency of a GNSS antenna according to an embodiment of the present application is provided, as the unavoidable losses introduced by the duplexer and filters are offset by the higher antenna gain, thus preserving the G / T ratio.

[0280] However, it is also apparent that a global navigation satellite system receiver must be adapted to a dense radio frequency spectrum, and that there are a large number of high-level, potentially interfering signals that can saturate and reduce the sensitivity of a global navigation satellite system receiver. These signals include, for example, industrial scientific and medical (ISM) band signals and mobile phone signals, in particular long term evolution (LTE) signals in the 700 MHz band, which are dangerous because the GNSS low noise amplifier can generate harmonics. Other potentially interfering signals include Globalstar (1610 MHz to 1618.25 MHz), Iridium (1616 MHz to 1626 MHz), and Inmarsat (1626 MHz to 1660.5 MHz), which are high-power uplink signals, with frequencies particularly close to GLONASS signals. Therefore, according to one embodiment of the present application, the LNA implemented by the inventors for a GNSS antenna is a compromise between final sensitivity and final interference rejection.

[0281] Therefore, according to one embodiment of the present application, the inventors have adopted defensive measures within the LNA in order to be used with a GNSS antenna. A first defensive measure is to add a multi-element bandpass filter at the antenna element terminals (before the LNA). Their typical insertion loss is 1 dB due to their tight passband and steep rejection characteristics, but the LNA noise figure is increased by approximately the additional filter insertion loss. A second defensive measure is to use a high linearity low noise amplifier, using a low noise amplifier chip that employs negative feedback to provide well-controlled impedance and gain over a very wide bandwidth without significantly increasing the low noise amplifier power consumption.

[0282] Importantly, considering that the antenna installation can have been initially determined to be free of interference, the subsequent introduction of new telecommunication services can change this, so interference protection is prudent even in quiet radio frequency environments. One potential undesirable side effect of a front-end filter is that the variable group delay across the filter passband can cause chromatic dispersion. Therefore, these criteria must be considered when selecting a suitable pre-filter. The inventors have established filters in LNAs at low GNSS frequencies (from 1160 MHz to 1300 MHz) and high GNSS frequencies (from 1539 MHz to 1610 MHz) that produce a maximum group delay variation of less than 10 nanoseconds. The inventors have established two LNA variants, one is a 28 dB gain LNA, embedded in the electronic components 140 of the GNSS antenna microwave / radio frequency circuitry, and the other is a 37 dB LNA, for long coaxial cable installations. The microwave / radio frequency circuitry within the Global Navigation Satellite System antenna electronics 140 is internally regulated to allow a power supply voltage of 3V to 16V.

[0283] In the foregoing description, specific details are set forth to provide a thorough understanding of embodiments of the application. However, it will be appreciated that embodiments can be practiced without these specific details.

[0284] The foregoing disclosure of exemplary embodiments of the application has been presented for the purposes of illustration and description. The application is not intended to be exhaustive or to limit the application to the precise forms disclosed. Many variations and modifications well be apparent to those of ordinary skill in the art in light of the above teachings. The scope of the application is to be accorded the broadest interpretation of the appended claims to encompass all of the features which encompass the essential characteristics of the application.

Claims

1. A wideband antenna comprising: a ground plane substrate having a defined center and comprising a first metallization layer forming a ground plane of the antenna; a pair of opposing petals metallized on a petal substrate, wherein each petal of the pair of opposing petals is electrically isolated and geometrically identical and comprises a first wider end and a second distal narrower end arranged collinearly along a first petal axis, wherein a width of the metallized petal decreases gradually from the first wider end to the second distal narrower end, a proximal end of the pair of opposing petals is a distal second end, a petal substrate center is located at a midpoint between the metallized petals; a dipole substrate arranged between the ground plane and the petal substrate; a second metallization layer orthogonal to the ground plane, the second metallization layer being patterned to provide a dipole in a plane of the dipole substrate, the dipole substrate comprising a pair of identical dipole elements having a predetermined geometric shape arranged collinearly on a first dipole axis, parallel to the ground plane substrate, and connected at their proximal ends to a first dipole feed point and a second dipole feed point, respectively, wherein the first petal axis and the first dipole axis are each linearly aligned with a center concentric to the ground plane center; the petal substrate center is offset at a predetermined distance above the ground plane; the petal substrate is curved symmetrically around the petal substrate center to form the metallized petals into identical three-dimensional shapes; a spacing between a lower surface of each metallized petal of the pair of opposing petals and a nearest edge of an adjacent dipole element has a predetermined profile radial from the ground plane center; and the dipole effectively constitutes a wideband distributed feed network by electromagnetic coupling without direct electrical connection to the pair of opposing petals.

2. The antenna of claim 1, wherein the first dipole feed point is electrically connected to a first circuit node on the ground plane substrate via a first transmission line to provide a first balanced feed point at the first circuit node; and the second dipole feed point is electrically connected to a second circuit node on the ground plane substrate via a second transmission line to provide a second balanced feed point at the second circuit node.

3. The antenna of claim 1, wherein the pair of dipole elements are patterned on the dipole substrate as mirror images around a center line of the dipole substrate; the second dipole feed point is electrically connected to a first circuit node on the ground plane substrate via a microstrip feed line; a first microstrip ground trace of the microstrip feed line has a predetermined width and is electrically connected to the first dipole feed point and the ground plane; a second microstrip ground trace, which is a mirror image of the first microstrip ground trace, is electrically connected to the second dipole feed point and the ground plane; and the first circuit node provides an unbalanced signal feed to the antenna.

4. The antenna of claim 3, wherein the three-dimensional shape is a spherical shape.

5. The antenna of claim 3, wherein the ground plane substrate further comprises a pair of center mounting slots and a plurality of peripheral mounting slots; The pair of opposing metallized petals formed on the petal substrate, each pair of petals having one or more connecting tabs at a first wider end, the connecting tabs arranged further from the second distal narrower end than the first wider end; and The connecting tabs of the pair of opposing metallized petals force the petal substrate to form the three-dimensional shape when inserted into a predetermined mounting slot of the plurality of peripheral mounting slots, and have a predetermined ground capacitance for each petal of the pair of opposing metallized petals.

6. The antenna of claim 3, wherein The ground plane substrate further comprises a pair of central mounting slots and a plurality of peripheral mounting slots; The pair of opposing metallized petals formed on the petal substrate, each pair of petals having a metallized region electrically isolated from the metallized petals arranged sequentially from the first wider end to the second distal narrower end; The one or more connecting tabs force the semi-flexible substrate to form the three-dimensional shape when inserted into one or more predetermined mounting slots of the plurality of peripheral mounting slots; and The one or more connecting tabs are connected to ground, presenting a predetermined capacitance between each metallized petal of the pair of opposing metallized petals and ground.

7. The antenna of claim 3, wherein The inner surfaces of the opposing petals are aligned along a first petal axis with the upper edge surface of the dipole substrate, concentric with the ground plane center, and physically contact over a predetermined portion of their length, whereby the linear dimension of the first axis of the pair of opposing petals is determined by the upper edge surface of the dipole along its central axis.

8. A wideband linearly polarized antenna, comprising: a ground plane substrate having at least two metal layers, wherein the upper metal layer is continuously metallized to comprise a ground plane surface, and having a central mounting slot and a plurality of peripheral mounting slots; a pair of opposing petals etched in metal on a semi-flexible substrate, wherein each petal of the pair of opposing petals is electrically isolated, geometrically identical, and comprises a first wider end and a second distal narrower end arranged collinearly along a first petal axis, wherein the width of the metallized petal decreases from the first wider end to the second distal narrower end, the proximal end of the pair of opposing petals being the distal second end, the petal substrate center being located at the midpoint between the metallized petals; a dipole substrate having a balun and a narrowband dipole pressed into metal layers on the dipole substrate, the balun connected to metallized terminals on a protruding lug located at the center of the lower edge of the dipole substrate, the lug arranged between the ground plane and the petal substrate; orthogonal to the ground plane, a second metallized layer is patterned to provide a dipole in the plane of the dipole substrate, the dipole substrate comprising a pair of identical dipole elements having a predetermined geometry, arranged collinearly on a first dipole axis, parallel to the ground plane; a three-dimensional structure comprising the dipole substrate mounted on the ground plane substrate, the protruding lug inserted into the central mounting slot, located in a plane orthogonal to the ground plane; each of the petals has a plurality of metallized tabs at the wider end, electrically isolated from the metallized petals, the semi-flexible substrate having sufficient length to form an arch by inserting the tabs into peripheral mounting slots of the ground plane; and the upper edge of the dipole substrate is sculpted to provide precise spacing between the opposing pair of petals and the narrow band dipole, whereby the narrow band dipole effectively constitutes a wide band distributed feed network by electromagnetic coupling without direct electrical connection to the opposing pair of petals.

9. The wideband linearly polarized antenna of claim 8, wherein each of the petals has a plurality of metallized tabs at the wider end of the opposing pair of petals; the plurality of metallized tabs are electrically connected by the conductive metallized links, the plurality of metallized links being immediately adjacent to the tabs and parallel to the wider end of the metallized petals; the metallized tabs are connected to the ground plane; the metallized links are disconnected from the metallized petals by non-metallized openings between the metallized links and the metallized petals; and each of the pair of opposing metallized petals has a predetermined capacitive impedance to ground.

10. The wideband linearly polarized antenna of claim 9, wherein each of the pair of opposing petals has a plurality of non-metallized slots etched in the petal metallization, the non-metallized slots being parallel to the petal axis, having a predetermined number, length and width on the semi-flexible substrate, terminating at the edges of the wider end of the metallized petals and the non-metallized openings.

11. The wideband linearly polarized antenna of claim 8, wherein the low frequency response of the wideband linearly polarized antenna is dependent on the capacitive reactance between the first wider end of the metallized petals and the ground of the ground plane substrate.

12. The wideband linearly polarized antenna of claim 8, further comprising a metallized disc disposed in the center of the petal substrate presenting equal capacitive reactance to all of the opposing pair of petals; wherein the capacitive reactance presents a capacitive impedance to ground independent of direct ground connections; the high frequency response of the wideband linearly polarized antenna is dependent on the capacitive reactance at the distal narrower end of each petal of the opposing pair of petals, and the spacing between the metallized disc and the distal narrower end of each petal of the opposing pair of petals.

13. An antenna, comprising: a ground plane substrate comprising a first metallized layer forming an antenna ground plane; a first pair of opposing metallized petals colinearly disposed, each petal of the first pair of metallized petals being identical and comprising a first wider end and a second distal narrower end, with a central axis longer than the width of the petal, wherein the width decreases from the first wider end to the second distal narrower end, the proximal end of the first pair of opposing metallized petals being the distal narrower end, and defining a midpoint between the pair of opposing metallized petals on their common linear axis as the geometric center of the antenna; a second pair of opposing metallized petals colinearly disposed, each petal of the second pair of metallized petals being identical and comprising a first wider end and a second distal narrower end, with a central axis longer than the width of the petal, wherein the width decreases from the first wider end to the second distal narrower end, the proximal end of the second pair of opposing metallized petals being the distal narrower end, and defining a midpoint between the pair of opposing metallized petals on their common linear axis as the geometric center of the antenna; a second pair of opposing metallized petals, co-linearly arranged, each petal of the second pair of metallized petals identical and comprising a first wider end and a second distal narrower end, with a central axis longer than the width of the petal, wherein the width decreases gradually from the first wider end to the second distal narrower end, the proximal end of the pair of opposing metallized petals being the second distal narrower end, and the midpoint between the second pair of opposing metallized petals is aligned with the geometric center of the antenna; a first dipole substrate comprising a second metallization layer, the second metallization layer being patterned to provide a first narrowband dipole, the first narrowband dipole comprising a pair of dipole elements and a pair of interconnection tracks connecting each element of the first narrowband dipole to a predetermined metallized terminal of a pair of metallized terminals; and a second dipole substrate comprising a third metallization layer, the third metallization layer being patterned to provide a second narrowband dipole, the second narrowband dipole comprising another pair of dipole elements and another pair of interconnection tracks connecting each element of the second narrowband dipole to a predetermined metallized terminal of a pair of metallized terminals; wherein the first narrowband dipole is aligned with the geometric center of the antenna and perpendicular to the ground plane; the second narrowband dipole is aligned with the geometric center of the antenna, perpendicular to the ground plane and perpendicular to the first narrowband dipole; the central axis of each petal of the first pair of opposing metallized petals is aligned with the first narrowband dipole; the central axis of each petal of the second pair of opposing metallized petals is aligned with the second narrowband dipole; the first wider end of each petal has a predetermined spacing from the ground plane; the first pair of opposing metallized petals has a three-dimensional geometry such that the spacing between the inner surface of each metallized petal and the nearest edge of the relevant dipole element of its first narrowband dipole varies in a predetermined manner with height from its first wider end to its second distal narrower end; and the second pair of opposing metallized petals has a three-dimensional geometry such that the spacing between the inner surface of each metallized petal and the nearest edge of the relevant dipole element of its second narrowband dipole varies in a predetermined manner with height from its first wider end to its second distal narrower end.

14. The antenna of claim 13, wherein the narrowband dipole further comprises a balun; and at least one inner surface of each metallized petal is spherical.

15. The antenna of claim 13, wherein the ground plane substrate further comprises a pair of central mounting slots and a plurality of peripheral mounting slots; and the pair of opposing metallized petals are formed on a semi-flexible dielectric substrate, and each pair of petals has one or more connection tabs at the first wider end, the connection tabs being arranged further from the second distal narrower end than the first wider end; and when inserted into a predetermined mounting slot of the plurality of peripheral mounting slots, the connection tabs of the pair of opposing metallized petals force the semi-flexible dielectric substrate to form a domed structure, and for each petal of the pair of opposing metallized petals, have a predetermined ground capacitance.

16. The antenna of claim 13, wherein the ground plane substrate further comprises a pair of center mounting slots and a plurality of peripheral mounting slots; and the pair of opposing metallized petals are formed on a semi-flexible dielectric substrate and each pair of petals are arranged sequentially from the first wider end to the second distal narrower end, the metallized regions are electrically isolated from the metallized petals and the one or more connecting tabs, wherein the metallized regions are located between the first wider end and the one or more connecting tabs of the metallized petals of the pair of opposing metallized petals, connected to ground, and exhibit a predetermined capacitance to the metallized petals of the pair of opposing metallized petals; and when the one or more connecting tabs are inserted into one or more predetermined mounting slots of the plurality of peripheral mounting slots, the one or more connecting tabs force the semi-flexible dielectric substrate to form an arched structure.

17. The antenna of claim 13, wherein the shape of the upper surface of the dipole substrate is such that the inner surface of each metallized petal along its central axis is defined by the upper surface of the dipole substrate over a predetermined portion of the length of the metallized petal.

18. The antenna of claim 13, further comprising a third pair of opposing metallized petals arranged collinearly, each petal of the third pair of metallized petals being identical and comprising a first wider end and a second distal narrower end, with a central axis longer than the width of the petal, wherein the width decreases gradually from the first wider end to the second distal narrower end, the proximal end of the first pair of opposing metallized petals being the second distal narrower end and defining a midpoint between the pair of opposing metallized petals on their common linear axis as the geometric center of the antenna; a fourth pair of opposing metallized petals arranged collinearly, each petal of the fourth pair of metallized petals being identical and comprising a first wider end and a second distal narrower end, with a central axis longer than the width of the petal, wherein the width decreases gradually from the first wider end to the second distal narrower end, the proximal end of the pair of opposing metallized petals being the second distal narrower end and the midpoint between the second pair of opposing metallized petals is aligned with the geometric center of the antenna; wherein the third pair of opposing metallized petals and the fourth pair of opposing metallized petals are arranged orthogonally to each other; the third pair of opposing metallized petals and the fourth pair of opposing metallized petals are arranged at 45° to each of the first pair of opposing metallized petals and the second pair of opposing metallized petals; and the first pair of opposing metallized petals, the second pair of opposing metallized petals, the third pair of opposing metallized petals, and the fourth pair of opposing metallized petals are all arranged on a common surface.

19. The antenna of claim 18, wherein the common surface is hemispherical.

20. The antenna of claim 18, further comprising a metallic element arranged between the second distal end of each petal of the first pair of opposing metallized petals and the second distal end of the petals of the second pair of opposing metallized petals; wherein a metal disc is capacitively coupled to the central end of the pairs of opposing metallized petals; and the linear dimension of the metal element depends on the tuning to be applied to the first and second pairs of opposing metallized petals.

21. The antenna of claim 13, further comprising a third pair of opposing metallized petals arranged collinearly, each petal of the third pair of metallized petals being identical and comprising a first wider end and a second distal narrower end, with a central axis longer than the width of the petal, wherein the width gradually decreases from the first wider end to the second distal narrower end, the proximal end of the first pair of opposing metallized petals being the second distal narrower end, and defining a midpoint between a pair of opposing metallized petals on their common linear axis as the geometric center of the antenna; a fourth pair of opposing metallized petals arranged collinearly, each petal of the fourth pair of metallized petals being identical and comprising a first wider end and a second distal narrower end, with a central axis longer than the width of the petal, wherein the width gradually decreases from the first wider end to the second distal narrower end, the proximal end of the pair of opposing metallized petals being the second distal narrower end, and the midpoint between the second pair of opposing metallized petals is aligned with the geometric center of the antenna; a first support, a second support, a third support, and a fourth support; wherein the third and fourth pairs of opposing metallized petals are arranged orthogonally to each other; the third and fourth pairs of opposing metallized petals are arranged at 45° to each of the first and second pairs of opposing metallized petals; the first, second, third, and fourth pairs of opposing metallized petals are all arranged on a common surface; the first and second supports are axially aligned with each other and with the central axis of the third pair of opposing metallized petals; and the third and fourth supports are axially aligned with each other and with the central axis of the fourth pair of opposing metallized petals.

22. The antenna of claim 21, wherein a predetermined portion of the upper edges of the first, second, third, and fourth supports have a predetermined profile; a predetermined portion of each end of the first dipole substrate has a predetermined profile; a predetermined portion of each end of the second dipole substrate has a predetermined profile; and the geometry of the predetermined portion of each petal of the first pair of opposing metallized petals when connected to the ground plane substrate is defined by the predetermined profile on each end of the first dipole substrate; the geometry of the predetermined portion of each petal of the second pair of opposing metallized petals when connected to the ground plane substrate is defined by the predetermined profile on each end of the second dipole substrate; the geometry of the predetermined portion of each petal of the third pair of opposing metallized petals when connected to the ground plane substrate is defined by the predetermined profile on the first and second supports associated therewith; and The geometry of the predetermined portion of each of the fourth pair of opposing metallized petals when connected to the ground plane substrate is defined by the predetermined profile on its associated third and fourth support members.

23. A wideband circularly polarized antenna comprising: a ground plane substrate having at least two metal layers, wherein the upper metal layer is continuously metallized to comprise a ground plane surface, and having a first central mounting slot and a second central mounting slot concentric and orthogonal to the first central mounting slot, and a plurality of peripheral mounting slots, first and second dipole substrates of identical external dimensions, uniformly patterned thereon with a balun and narrowband dipoles stamped in the metal layer of the dipole substrates, the balun connected to metallized terminals on the lower edge central protruding lugs of the dipole substrates, the first and second dipole substrates comprising interlocking slots for assembly of a three-dimensional crossed dipole structure, an assembly, consisting of the orthogonal dipole structure, mounted on the ground plane substrate by inserting the respective protruding lugs into the first and second central mounting slots, the first and second balun feed connections feeding a first and second output of a feed circuit consisting of an RF 90-degree coupler, first and second pairs of opposing petals, each pair of petals consisting of a first petal and a distal second petal, the first and distal second petals etched in metal having a non-conductive edge, on each of the identical dimension semi-flexible substrates, each petal having a wider end and a distal narrower end, the central axis longer than the wider end, and a width between the wider end and the narrower end tapering, the first and second petals being collinear, the proximal end of the first and second petals being the narrower end, the axes of the first and second pairs of opposing petals being orthogonal to each other, the common midpoint of the first and second petals on the extended axis of each axis defining the antenna geometric center, each of the metallized petals having a plurality of metallized connection tabs electrically isolated from the metallized petal, the semi-flexible substrates having sufficient length to form a dome structure by inserting the connection tabs into the peripheral mounting slots in the ground plane, the pairs of petals being aligned along the axis of the crossed dipole, the upper edges of the first and second dipole substrates being sculpted to identical shapes to provide precise spacing between the pairs of opposing petals and the narrowband dipoles, whereby the narrowband dipoles effectively constitute a wideband distributed feed network for the circularly polarized antenna by electromagnetic coupling, without direct electrical connection to the pairs of opposing petals.

24. The wideband circularly polarized antenna of claim 23, wherein the plurality of metallized connection tabs are associated with one of each of the metallized petals, electrically connected by thin conductive metallized links, each metallized link immediately adjacent to a connection tab and parallel to the wider end of the metallized petal; the metallized links are electrically isolated from the metallized petal by a narrow non-metallized opening between the metallized link and the metallized petal; and the metallized links are electrically connected to ground and provide a predetermined capacitance to their associated metallized petal.

25. The wideband circularly polarized antenna of claim 24, wherein each of the first and second pairs of opposing petals has a plurality of non- metallized slots parallel to the petal axis, etched in the semi-flexible substrate in a predetermined number, length and width, terminating at the wider end of the metallized petal and the edge of the non-metallized opening.

26. A wideband circularly polarized antenna comprising: a ground plane substrate having at least two metal layers, wherein the upper metal layer is continuously metallized to include the ground plane surface and has a first central mounting slot and a second central mounting slot concentric and orthogonal to the first central mounting slot, and a plurality of peripheral mounting slots, first and second dipole substrates of identical external dimensions, each uniformly etched with a balun and narrowband dipoles printed in the metal layer of the dipole substrate, the balun connected to metallized terminals on the lower edge central protruding tabs of the dipole substrate, the first and second dipole substrates including interlocking slots for assembly of a three-dimensional crossed dipole structure, an assembly including the orthogonal dipole structure mounted on the ground plane substrate by inserting the respective tabs of the protruding tabs into the first and second central mounting slots, and four gap support substrates mounted perpendicular to the ground plane, each gap support substrate rotated 45 degrees with respect to any of the axes of the crossed dipoles so as to be similarly disposed in each quadrant of the crossed dipole structure, each gap support substrate having the same upper profile as the crossed dipoles, first and second outputs of a feed circuit comprised of RF 90 degree couplers when the first and second balun feed lines are connected, first, second, third and fourth pairs of petals, each pair of petals composed of a first petal and a distal second petal, the first and distal second petals etched in metal having non-conductive edges, on each of the semi-flexible substrates of identical dimensions, each petal having a wider end and a distal narrower end, a central axis longer than the wider end, the first and second petals being collinear, the proximal ends of the first and second petals being the narrower ends, the axes of the arbitrary second pair of petals rotated 45 degrees with respect to the axes of the first pair of petals, the rotation between the third pair of petals and the second pair of petals, the fourth pair of petals and the third pair of petals being equal, a common midpoint between the first and second petals on the extended axis of each of the axes of each pair of petals, defined as the antenna geometric center, each of the metallized petals having a plurality of metallized tabs electrically isolated from the metallized petal at the wider end, the semi-flexible substrate having sufficient length to form a dome structure by inserting the tabs into the peripheral mounting slots in the ground plane, at least one of the pairs of petals aligned along the axis of one of the crossed dipoles, The upper edges of the first and second dipole substrates are sculpted to the same shape to provide precise spacing between opposing pairs of the relative lobes associated with each of the narrowband dipoles, the upper edges of the interstitial support substrate are further sculpted to the same shape as the dipole substrates, whereby the narrowband dipoles effectively constitute a wideband distributed feed network for a circularly polarized antenna by electromagnetic coupling without direct electrical connection to the opposing pairs of lobes.

27. The wideband circularly polarized antenna of claim 26, wherein The plurality of metallized tabs are associated with one of each of the metallized lobes, electrically connected by thin conductive metallized links, each metallized link immediately adjacent to a tab and parallel to the wider end edge of the metallized lobe; The metallized links are electrically isolated from each metallized lobe by a narrow, non-metallized opening between the metallized link and the metallized lobe; And The metallized links are electrically connected to ground and provide a predetermined capacitance to their associated metallized lobe.

28. The wideband circularly polarized antenna of claim 27, wherein Each lobe of the first and second pairs of opposing lobes has a plurality of non-metallized slots, the slots parallel to the lobe axis, etched into the semi-flexible substrate in a predetermined number, length and width, terminating at the edge of the wider end of the metallized lobe and the non-metallized opening.

29. A method of receiving a circularly polarized radio frequency signal, comprising: providing a first pair of opposing metallized lobes disposed above a ground plane and having a predetermined three-dimensional profile with respect to the ground plane; providing a second pair of opposing metallized lobes disposed above the ground plane and orthogonal to the first pair of opposing metallized lobes and having the same predetermined three-dimensional profile as the first pair of opposing metallized lobes; a first dipole comprising a pair of first dipole elements aligned with the first pair of opposing metallized lobes; a second dipole comprising a pair of second dipole elements aligned with the second pair of opposing metallized lobes; wherein a distance from an upper edge of each first dipole element to a respective lobe of the first pair of opposing metallized lobes has a predetermined profile as a function of an elevation angle from the ground plane; and a distance from an upper edge of each second dipole element to a respective lobe of the second pair of opposing metallized lobes has a predetermined profile as a function of an elevation angle from the ground plane; the resulting antenna reduces roll-off from high elevation angles to low elevation angles.

30. A method of receiving a circularly polarized radio frequency signal, comprising: providing a first narrowband dipole electrically connected to a feed network; providing a second narrowband dipole orthogonal to the first narrowband dipole and electrically connected to the feed network; providing a first pair of opposing metallized lobes disposed above a ground plane and having a predetermined three-dimensional profile with respect to the ground plane; providing a second pair of opposing metallized lobes disposed above the ground plane and orthogonal to the first pair of opposing metallized lobes and having the same predetermined three-dimensional profile as the first pair of opposing metallized lobes; wherein the first narrow-band dipole and the first pair of opposing metallized petals are axially aligned with each other; the second narrow-band dipole and the second pair of opposing metallized petals are axially aligned with each other; the first pair of opposing metallized petals provide a wide-band antenna element that is radiatively coupled to the feed network via the first narrow-band dipole; and the second pair of opposing metallized petals provide a wide-band antenna element that is radiatively coupled to the feed network via the second narrow-band dipole, respectively.

31. The method of claim 30, wherein the relative phases of the received signals coupled from the first narrow-band dipole to the feed network are 0° and 180°; and the relative phases of the received signals coupled from the second narrow-band dipole to the feed network are 90° and 270°.

32. A wide-band antenna, comprising: a ground plane substrate having at least two metal layers, wherein the upper metal layer is continuously metallized to comprise a ground plane surface and has a central mounting slot and a plurality of peripheral mounting slots, a first pair of opposing petals etched in metal on a semi-flexible substrate, wherein each petal of the pair of opposing petals is electrically isolated, geometrically identical, comprises a first wider end and a second distal narrower end, the first wider end and the second distal narrower end are colinearly arranged along a first petal axis parallel to the ground plane, the proximal end of the pair of opposing petals is the second distal narrower end, a petal substrate center is defined as the midpoint between the metallized petals; and a second pair of opposing petals etched in metal on a semi-flexible substrate, configured identically to the first pair of opposing petals, arranged along a second petal axis parallel to the ground plane and orthogonal to the first petal axis, arranged concentrically to the first pair of opposing petals; a plurality of metallized connection patches sequentially arranged distal to each petal substrate center and further than the first wider end of each metallized petal, connected to an adjoining metallized region, wherein each metallized connection patch of the plurality of connection patches is electrically isolated from the metallized layer of the associated petal of the first pair of opposing petals or the second pair of opposing petals; a first dipole substrate arranged between the ground plane and the petal substrate, the petal substrate being orthogonal to the ground plane, the petal substrate having a second metallized layer patterned to provide a first dipole in the plane of the dipole substrate, the first dipole substrate comprising a first pair of identical dipole elements connected at their proximal ends to provide a first balanced dipole feed; and a second dipole substrate configured identically to the first dipole substrate, the first dipole substrate being orthogonal to the ground plane, the ground plane arranged along an axis of the second dipole orthogonal to the axis of the first dipole, the second dipole substrate comprising a second pair of identical dipole elements connected at their proximal ends to provide a second balanced dipole feed; wherein the semi-flexible substrate has sufficient length to form an arcuate structure by inserting the metallized connection patches into the peripheral mounting slots in the ground plane; each metallized region is connected to ground through the metallized connection patches; engraving an upper edge of the first dipole substrate to provide a predetermined spacing between an inner surface of each wing of one of the first pair of opposing wings or the second pair of opposing wings and the first pair of identical dipole elements; engraving an upper edge of the second dipole substrate to provide a predetermined spacing between an inner surface of each wing of the first pair of opposing wings or the second pair of opposing wings and the second pair of identical dipole elements; wherein the first and second dipoles that are electromagnetically coupled include a wideband distributed feed network on two orthogonal axes without direct electrical connections between the first dipole, the second dipole, the first pair of wings, and the second pair of wings.

33. The antenna of claim 32, wherein the first dipole substrate includes a first integrated balun; the second dipole substrate includes a second integrated balun.

34. The antenna of claim 32, wherein the first dipole substrate includes a first integrated balun; the second dipole substrate includes a second integrated balun; and the antenna further includes a dual feed network coupled to the first and second integrated baluns.

35. The antenna of claim 34, further comprising a first feed coupled to the first dipole via the first integrated balun integrated on the first dipole substrate; a second feed coupled to the second dipole via the second integrated balun integrated on the second dipole substrate; and a dual feed network to couple the first and second feeds to a common feed port; wherein the dual feed network couples signals from the common feed port to the first and second dipoles such that the signals are identical except for being offset 90 degrees relative to each other in a predetermined direction such that the antenna is a circularly polarized antenna.

36. The antenna of claim 35, wherein in a first predetermined direction, the antenna is a left-hand circularly polarized antenna; and in a second predetermined direction, the antenna is a right-hand circularly polarized antenna. ​

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