High-gain tightly coupled dipole antenna array

Abstract

To provide an antenna system comprising an antenna reactively loaded to control the directivity of the antenna.SOLUTION: An antenna system 100 includes an array of conductors 104 connected to a feed line. The array emits electromagnetic radiation in response to an input signal being input to the array through the feed line, and outputs an output signal to the feed line in response to electromagnetic radiation being received on the array. A director 106 disposed in front of the array has a first reactive load 135 having a complex impedance that is tailored to increase the directivity of the antenna system by reactively loading the conductors 104.SELECTED DRAWING: Figure 1B

Description

[Technical Field]

[0001] The present disclosure relates to antenna systems and methods of making antenna systems. [Background technology]

[0002] A tightly coupled dipole antenna array (TCDA) comprises an array of dipoles that provides wideband and wide-angle performance for transmitter / receiver applications. However, for some applications, it is desirable to obtain increased directivity and gain over a narrower angle. The present disclosure fulfills this need. Summary of the Invention

[0003] Disclosed herein is an antenna system having enhanced directivity. Exemplary, non-exclusive examples of the inventive subject matter according to the present disclosure are described in the following enumerated paragraphs.

[0004] A1. 1. An antenna system comprising an array of conductors coupled to a feedline and a director positioned in front of the array, the array comprising: emitting electromagnetic radiation in response to an input signal being input to the array via the feed line; or outputting an output signal onto the feed line in response to electromagnetic radiation being received at the array; The director is connected to the conductor. Reactive a first complex impedance adjusted to increase the directivity of the antenna system by loading it; Reactive An antenna system having a load.

[0005] A2. The antenna system of paragraph A1, further comprising a reflector positioned behind the array, the reflector configured to reflect a portion of the electromagnetic radiation received at the reflector, including the received electromagnetic radiation, toward the director.

[0006] A3. The reflector is a second Reactive With load, The second Reactive The antenna system of paragraph A2, wherein a load has a second complex impedance that adjusts the reflection of the received electromagnetic radiation directed toward the director.

[0007] A4. the reflector comprises a printed circuit board; the printed circuit board comprises conductor tracks; The antenna system of paragraph A3, wherein the conductor track has at least one of a thickness or a serpentine path that varies as a function of position along the length of the reflector to adjust the second complex impedance.

[0008] A5. the director comprises a printed circuit board; the printed circuit board includes a circuit; The circuit is Reactive One or more load forming Reactive An antenna system according to any one of paragraphs A1 to A4, having an impedance

[0009] A6. The antenna system of paragraph A5, wherein the circuitry includes circuit elements configured to control the phase of the electromagnetic radiation at various locations along the length of the array to enhance the directivity by adjusting at least one of destructive interference or constructive interference of the electromagnetic radiation at the various locations.

[0010] A7. One or more of the above Reactive The antenna system of paragraph A5 or A6, wherein the impedance includes capacitive reactance and inductive reactance.

[0011] A8. The first Reactive The load comprises an array of circuit elements, each of the circuit elements comprising: a first capacitor; and a second capacitor in parallel with the coil; The antenna system of any of paragraphs A1 to A7, wherein the first capacitor is in series with the combination of the second capacitor and the coil.

[0012] A9. the conductors are periodically arranged along the array with a period P; The first Reactive The antenna system of any of paragraphs A1 to A8, wherein the load comprises an array of the circuit elements arranged at the period P along the length of the director.

[0013] A10. The method further includes a first microstrip comprising the array and a second microstrip comprising the director, the first microstrip comprising: the conductor, conductive backplane, a first dielectric disposed between the conductor and the conductive backplane; and further comprising a plurality of loads, each of the loads connecting one of the conductors to an adjacent one of the conductors; The second microstrip is Reactive Further equipped with load, The first Reactive the load comprises a plurality of conductive components separated by one or more dielectric layers; The antenna system of any of paragraphs A1 to A9, wherein the plurality of conductive components comprises at least one of a capacitance pad or a wire having inductance.

[0014] A11. a third microstrip having a reflector disposed behind the array; The third microstrip includes a wire having at least one of a varying thickness or a meandering path that varies the inductance of the wire along the length of the third microstrip. Reactive The antenna system of paragraph A10, including a load.

[0015] A12. The antenna system of paragraph A11, wherein the first microstrip, the second microstrip, and the third microstrip are parallel, coplanar, and have the same length.

[0016] A13. the distance between the array and the director is within 10% of λ / 4; the distance between the array and the reflector is within 10% of λ / 8; The antenna system of any one of paragraphs A1 to A12, wherein λ is the longest wavelength of the radiation.

[0017] A14. The first Reactive load and the second Reactive The load is the frequency of said electromagnetic radiation in the range between 10 MHz and 10 GHz, and The antenna system of any of paragraphs A3 to A13, wherein the directivity of the antenna is adjusted as a function of

[0018] A15. The antenna system of any of paragraphs A1 to A14, wherein the directivity includes focusing the electromagnetic radiation onto or from a sidewall of the array opposite the director.

[0019] A16. The antenna system of any of paragraphs A1 to A15, wherein the director is configured such that the directivity includes concentrating the electromagnetic radiation in an elevation direction away from or toward the horizontal.

[0020] A17. The antenna system of any of paragraphs A1 to A16, wherein the array includes a tightly coupled dipole array (TCDA) or a multi-tap antenna.

[0021] A18. the conductors each have a length within 10% of λ / 10; the conductors are separated by a distance within 10% of λ / 100; The antenna system of paragraph A17, wherein λ is the longest wavelength of the electromagnetic radiation.

[0022] A19. the electric field generated by the electromagnetic radiation in one of the conductors and experienced in the next adjacent one of the conductors is 1 / d 2 the near-field amplitude proportional to 1 / d 3 is proportional to Reactive the conductors are capacitively coupled or coupled by near-field interaction of the electric field to have a near-field amplitude; The antenna system of paragraph A17 or A18, wherein d is the distance separating said one of said conductors from said next adjacent one of said conductors.

[0023] A20. further comprising an aircraft structure; the aircraft structure comprises or is attached to a reflector positioned behind the array; the reflector is configured such that a portion of the electromagnetic radiation received at the reflector, including the received electromagnetic radiation, is reflected toward the director; The antenna system of any of paragraphs A1 to A19, wherein the aircraft structure further includes a skin, a wing spar, a bulkhead, or a wing leading edge.

[0024] A21. An aircraft equipped with any one of the antenna systems of paragraphs A1 to A20.

[0025] A22. 1. A method of making an antenna system, comprising: Obtaining a multi-tap antenna comprising an array of conductors and a plurality of loads connecting said array of conductors; The multi-tap antenna is emitting electromagnetic radiation in response to an input signal being input to said multi-tap antenna via a feed line; or coupling the feed line to the array of conductors such that the feed line is configured to: output an output signal to the feed line in response to electromagnetic radiation being received at the multi-tap antenna; placing a director in front of the multi-tap antenna, the director having a director reactance that increases the directivity of the antenna system; and The method includes placing a reflector after the multi-tap antenna, the reflector having a reflector reactance that reflects the radiation toward the director.

[0026] A23. Varying the reflector reactance as a function of position along the length of the reflector; and The method of paragraph A22, further including adjusting at least one of destructive interference or constructive interference of the electromagnetic radiation at various locations along the length of the director by varying the director reactance along the length of the director, thereby controlling the phase of the electromagnetic radiation at the various locations along the length of the director.

[0027] A24. 1. A method of using an antenna system, comprising: Using a Tightly Coupled Dipole Antenna Array (TCDA) to transmit and receive radiation; and 20. The method of claim 19, further comprising: increasing the directivity of the antenna system using a director positioned in front of the TCDA and a reflector positioned behind the TCDA.

[0028] A25. The method of paragraph A24, wherein the directionality is directed toward the horizontal or waterline. [Brief explanation of the drawings]

[0029] [Figure 1A] 1 is a schematic diagram of an exemplary antenna system including a TCDA coupled to a director and a reflector. [Figure 1B] 1 is a schematic diagram of an exemplary antenna system including a TCDA coupled to a director and a reflector, where the TCDA, director, and reflector comprise microstrips. [Figure 1C] 1B is a graph comparing the directivity of the antenna system of FIG. 1A with the directivity of an antenna system without a reflector and director. [Figure 2] 1 illustrates an exemplary TCDA with a multi-tap antenna. [Figure 3A] 1 is a flowchart illustrating an exemplary method for designing a director or reflector. [Figure 3B] 1 is a graph plotting exemplary design parameters, surface impedance, Im(Zs), and tolerance function (zfunc) for an exemplary director as a function of frequency of electromagnetic radiation. [Figure 3C] 10 is a graph plotting an example design parameter Im(Zs) as a function of frequency for an example reflector. [Figure 4A] 1 is a cross-sectional schematic diagram of an exemplary director. [Figure 4B] FIG. 10 is an exemplary circuit diagram of reactive components within an exemplary director. [Figure 4C] FIG. 10 is a perspective view of an example director illustrating periodic placement of reactive loads within multiple unit cells. [Figure 5] FIG. 1 is a perspective view of an exemplary reflector. [Figure 6A] 1 illustrates an exemplary antenna system coupled to a wing spar, where the wing spar includes a reflector and the antenna system does not include a director. [Figure 6B]6B is a graph plotting the gain of the antenna system of FIG. 6A compared to the gain without a reflector. [Figure 7A] 1 illustrates an exemplary antenna system coupled to a spar, where the antenna system includes a reflector and a director, and the spar includes the reflector. [Figure 7B] 7B is a graph plotting the gain of the antenna system of FIG. 7A. [Figure 7C] 7B is a graph plotting the directivity of the antenna system of FIG. 7A. [Figure 7D] 1 shows the gain of the antenna system. [Figure 8] 1 illustrates an exemplary antenna system comprising a microstrip coupled to a spar. [Figure 9] 1 shows an exemplary antenna system with two directors and one reflector. [Figure 10A] 10 shows the gain of the antenna system of FIG. [Figure 10B] 10 shows the directivity of the antenna system of FIG. [Figure 11] FIG. 1 is a schematic diagram of an aircraft equipped with an antenna system according to any of the embodiments described herein. [Figure 12] 1 is a flowchart illustrating an exemplary method for making an antenna system. [Figure 13] 5 is a flowchart illustrating an exemplary method of using the antenna system. DETAILED DESCRIPTION OF THE INVENTION

[0030] In the following description, reference is made to the accompanying drawings, which form a part hereof and which show by way of illustration several embodiments, It is understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present disclosure.

[0031] Technical Description The present disclosure provides a method for controlling the directionality of electromagnetic radiation emitted from and / or received by an antenna. Reactive An antenna system is described that includes a loaded antenna (eg, a powered antenna). Reactive The load may include at least one of an inductive load or a capacitive load comprising one or more parallel circuit elements electromagnetically coupled to the antenna. In some embodiments, the circuit elements have complex impedances that are adjusted to vary the phase of the electric field or current experienced by each of the elements in the powered array. Reactive load, whereby the sum of the collective electric fields resulting from the destructive and / or constructive interference is the desired directional electric field pattern (electric fields are canceled in undesired directions).

[0032] Exemplary Antenna Systems 1A-1B show an exemplary antenna system 100 comprising an array 102 of conductors 104 disposed along a length L1 of the array 102. The antenna system 100 further includes a first reactive element (e.g., director 106) disposed on a first side 108 of the array 102 and a second reactive element (e.g., reflector 110) disposed on a second side 112 of the array 102, such that the array 102 is between the director 106 and the reflector 110. In the illustrated embodiment, the director 106 and the reflector 110 each are disposed on the array 102. Reactive Applying load Reactive The array 102 includes components such that the resulting directivity is an electric field pattern with maximum directivity along the x-direction, with electromagnetic radiation 113 being directed away from or towards sidewalls 114 ("knife edges") of the array 102. In one illustrated embodiment, the conductors 104 are connected by loads 116 and arranged along a line to form the array 102, which comprises a linear array. In some embodiments, the array 102 is designed to operate at a single frequency or a narrow range of frequencies of electromagnetic radiation 113.

[0033] In one or more embodiments, the director 106 comprises a combination of inductive and capacitive loads that control the phase of the electric field in each of the conductors 104 in the array 102, while the reflector 110 comprises primarily an inductive load that is tuned to reflect 119 electromagnetic radiation 113 toward the array 102 or the director 106. In some embodiments, the director 106 comprises a capacitive strip 120 comprising a capacitive load that includes a first rectangular metal layer on a first dielectric and has a length L2 that extends the length L1 of the array 102. The reflector comprises an inductive strip 122 comprising a second rectangular metal layer on a second dielectric and has a length L3 that extends the length L1 of the array 102. Both the reflector 110 and the director 106 have their lengths L3, L2 greater than their widths.

[0034] In one or more embodiments, the distance D1 between the director 106 and the array 102 and the distance D2 between the reflector 110 and the array 102 also affect the directivity and Reactive Load Reactive The distances are adjusted to control impedance. Exemplary distances include, but are not limited to, D1 within 10% of λ / 4 and D2 within 10% of λ / 8, where λ is the longest wavelength of electromagnetic radiation 113. In one or more embodiments, D2 is selected so that reflector 110 provides an inductive load and D1 is selected so that director 106 provides a capacitive load.

[0035] 1B shows an exemplary antenna system 100 implemented using a printed circuit board 124 comprising a microstrip having sidewalls 114. The array 102 comprises a first microstrip 126 comprising a conductor 104, a conductive backplane 128, and a first dielectric 130 between the conductor 104 and the conductive backplane 128. The director 106 comprises a second microstrip 132 including one or more first elements 134 combined with a second dielectric 136 to provide a director reactance (first Reactive Load 135 or first ReactiveThe reflector 110 includes a third microstrip 138 including one or more second components 140 coupled to a third dielectric 142 to form a reflector reactance (second Reactive Load 141 or second Reactive In various embodiments, the director reactance and reflector reactance control the phase of the electric fields or currents experienced in the various conductors 104 in the array 102 to adjust the destructive or constructive interference of the electric fields or currents experienced in each of the conductors 104. In one or more embodiments, the array 102 of conductors 104 is arranged across a conductive backplane 128. Reactive Loaded, Reactive Loading causes additional parasitic elements in the director 106 or reflector 110 to appear shorter (capacitive) or longer (inductive), thereby redirecting the directivity.

[0036] In various embodiments, the array 102, director 106, and reflector 110 may be formed on the same substrate or printed circuit board 124, or they may be formed on different substrates or printed circuit boards 124.

[0037] 1C shows an example directivity 144 achieved using the antenna system 100 of FIG. 1A compared to the directivity 146 without the director 106 and reflector 110. In some embodiments, the directivity 144 is selected to concentrate the electromagnetic radiation along the elevation (theta) direction (rather than azimuth), whereby the electromagnetic radiation is focused or concentrated at or from the horizon.

[0038] 1A-1B show the array 102 including a linear array of conductors 104, but other configurations of conductors 104 (e.g., non-linear configurations) are possible. As described in the next section, examples of an array 102 of conductors 104 include, but are not limited to, a fed array, a TCDA (in which the conductors 104 each comprise a dipole element), a phased array (in which one or more of the conductors 104 in the array 102 are driven, such that different conductors 104 in the array 102 experience electric fields or currents with different phases), or a multi-tap antenna.

[0039] Exemplary Arrays 2 shows an exemplary array comprising a multi-tap antenna 200 comprising a plurality of loads 116 (e.g., power lines) connecting the array of conductors 104 and a feedline 202 connected to the conductors 104. The multi-tap antenna 200 (1) Emitting electromagnetic radiation in response to an input signal being input to the multi-tap antenna 200 via the feedline 202; or (2) outputting an output signal onto the feed line 202 in response to electromagnetic radiation being received by the multi-tap antenna 200.

[0040] 2 shows an array of conductors 104 in which dipole elements are capacitively coupled or coupled by near-field interaction of electric fields, such that the electric field generated by electromagnetic radiation in one of the conductors 104 104a and experienced in the next adjacent one of the conductors 104 104b is (1) 1 / d 2 the near-field amplitude proportional to (2) 1 / d 3 is proportional to Reactive has a close-range amplitude, where d is the distance separating one of the conductors 104a from the next adjacent one of the conductors 104b.

[0041] Exemplary dimensions include, but are not limited to, conductors 104 with patches having a patch length L4 within 10% of λ / 10, and conductors 104 each separated by a distance d within 10% of λ / 100 (λ is the longest wavelength of electromagnetic radiation).

[0042] 2 further shows a module 204 connected to port 206. In one receiver embodiment, load 116 taps or receives energy or power from signals generated by conductors 104 when exposed to electromagnetic radiation, module 204 includes a combiner that combines the power received by load 116, and port 206 includes an output port that receives the power. In one receiver embodiment, loads 116 each have an impedance equal to a desired impedance for the output port. In one transmitter embodiment, module 204 includes a divider that divides the signal received at port 206, including the input port, to distribute the input signal transmitted to each of conductors 104. In this manner, power received by or transmitted to load 116 is captured or used in a manner that provides improved gain for multi-tap antenna 200.

[0043] The use of a load 116 (with taps) comprising conductors 104 increases the bandwidth of the TCDA comprising multi-tap antenna 200. In one or more embodiments, load 116 comprises resistive and / or capacitive elements to increase the bandwidth at which the antenna operates by introducing losses that destroy the resonant characteristics of multi-tap antenna 200 and reduce the efficiency (or gain) of multi-tap antenna 200.

[0044] Exemplary Director and Reflector Designs In some embodiments, the wave is provided by a director and / or a reflector. Reactive The load is identified by varying the dimensions, circuit design (including impedance), and spacing of the director and reflector and measuring the effect of the variations on the directivity. ReactiveThe loads are identified using electromagnetic simulation and modeling software.

[0045] FIG. 3A is a flow chart showing a method for designing director reactances and reflector reactances (also referred to in FIGS. 1A-1C and FIG. 2).

[0046] Block 300 represents obtaining a representation of the two-dimensional (2D) scattering cross section (e.g., radar cross section (RCS)) of the director 106 or reflector 110, having an echo width in decibels relative to a knife edge (flat strip sidewall 114), as a function of the surface impedance of the director 106 or reflector 110. In one or more embodiments, the 2D RCS of a single unit cell of the director 106 or reflector 110 is given by 2D RCS=E s =2χ / (χ α +Z s ) (1) where α=(1-2i / π·ln(τ / 4))τ=k0η0w / 4, χ=k0γw / 2, γ=1.781, and Z s is the surface impedance of a single unit cell, k0 is the frequency dependent wave vector of the electromagnetic radiation, and η0 is the resistive impedance.

[0047] Block 302 represents finding a solution for Es that has the desired directivity of the antenna system, including the director 106, the reflector 110, and the array 102. In one or more embodiments, Es is determined using finite element modeling of the director 106 and / or the reflector 110.

[0048] Block 304 represents finding one or more surface impedances Zs that match a desired solution for Es with a desired directivity. In one or more embodiments, the steps include: Z s =2χ / E s -χ α (2) This involves plotting the impedance as a function of the frequency of the electromagnetic radiation using a

[0049] Block 306 represents selecting the geometry and reactance of a single unit cell having an acceptable 2D RCS for two extremes of frequency within the bandwidth of the TCDA. In various embodiments, the acceptable RCS is identified using Zi1 and Zi2 (the imaginary parts of Zs at frequencies f1 and f2, respectively) and by minimizing the acceptable impedance ratio (or selecting an acceptable impedance ratio below a predetermined threshold). In one or more embodiments, the acceptable impedance ratio is determined by: 100x|(zfunc-im(Z s )) / zfunc|. where zfunc=Zi1+(f-f1) * ((Zi2-Zi1) / (f2-f1).

[0050] For one example range of frequencies and for directivity within a narrow cone oriented at the waterline or horizon, Figure 3B plots Im(Zs) and zfunc for a single unit cell of director 106, and Figure 3C plots Im(Zs) for reflector 110. A typical director 106 or reflector 110 includes multiple unit cells arranged (e.g., periodically) along the length L2, L3 of the director or reflector, respectively.

[0051] Exemplary Director and Reflector Structures FIG. 4A shows a first embodiment implemented as a transmission line or circuit element 401. Reactive An exemplary unit cell 400 within the second microstrip 132 (with the director 106) containing components is shown. The circuit element 401 is separated by one or more dielectric layers 402, 404. ReactiveThe unit cell 400 comprises a load C1, C2, and L including conductive components 134, where C1 forms a first capacitive reactance with a first conductive pad, C2 forms a second capacitive reactance with a second conductive pad, and L forms an inductive reactance with a wire or conductor track. Figure 4B is a circuit diagram of the unit cell 400, showing the second capacitive reactance (capacitor C2) in parallel with the inductive reactance (coil L) and the first capacitive reactance (capacitor C1) in series with the combination of the second capacitive reactance C2 and the inductive reactance L.

[0052] 4C shows an embodiment in which the second microstrip 132 comprises an array of unit cells 400 arranged along the length L2 of the microstrip with a period P (the period P being defined by the spacing d of the conductors 104 in the array 102, or an arrangement equivalent to the arrangement of the conductors 104 in the array 102, as shown in FIG. 1A or FIG. 2). In one or more embodiments, each unit cell 400 comprises the circuit element 401 of FIGS. 4A and 4B.

[0053] 5 shows an exemplary third microstrip 138 (with reflector 110) in which the second component 140 comprises a conductor track 502 (e.g., a dielectric wire 503) having at least one of a serpentine path 504 or a varying thickness 506 along the length of the reflector 110. Reducing the wire thickness 506 increases the inductance. Increasing the serpentine path 504 of the wire 503 or conductor track 502 also increases the inductance.

[0054] Exemplary Antenna Assembly and Performance 6A shows an antenna system 600 comprising an array 102 and a wing spar 602. In this case, the wing spar 602 comprises a reflector 110 or a metallic ground plane acting as a reflector 110.

[0055] 6B shows the gain of the array 102 (a linear array) without director 106 and without reflector 110 (full range of elevations), as well as the gain of the array 102 with reflector 110 but without director 106 (full range over half space or carotidal). The efficiency of the array 102 is Efficiency is given by g0 / 2kp·∫dθΓ(θ). where g is the gain for each fed element in the array 102, Γ(θ) is the normalized elevation pattern, p is the period of the fed elements, and k is the wavenumber of the electromagnetic radiation, 2π / λ. For an omnidirectional radiation pattern, g = 2p / λ. As shown in FIG. 6B, the antenna system including the wing spar 602 (but without the director 106) has 3 dB more gain compared to the directivity without the wing spar 602, assuming the array 102 is 100% efficient (whereby all conductors are matched with no resistive losses). The wing spar 602 allows the antenna system 600 to be omnidirectional over half the space (cardiodal).

[0056] Figure 7A shows an antenna system 600 including an array 102 (linear array), director 106, and reflector 110 combined with a wing spar 602 according to another embodiment (dimensions and reactances shown in Table 1). As shown in Figures 7B and 7C, the presence of director 106 significantly increases the gain and directivity of antenna system 600. Figure 7D shows that the gain of antenna system 600 does not change significantly when the load capacitance (the capacitance of load 116 in Figures 1A and 2) is changed from 9.3 pF to 8.87 pF and the capacitive reactance of the director is reduced from 6.7 pF per square to 6.67 pF per square.

[0057] 8 shows another embodiment of an antenna system 600 comprising a wing spar 602 comprising an array 102 (a linear array), a director 106, and a reflector 110. In this case, the director 106 comprises a unit cell 400 comprising circuit elements 401 and components 134 shown in FIGS. 4A, 4B, and 4C. TIFF2022113142000001.tif167170

[0058] FIG. 9 illustrates an example embodiment in which an antenna system 600 includes an array 102, multiple directors 106a, 106b positioned in front of the array 102 (on a first side 108 of the array 102), and a wing spar 602 including a reflector 110. FIGS. 10A and 10B illustrate the gain and directivity of the antenna system of FIG. 9 when the second director 106b is 14 inches from the wing spar 602 and the array 102 is a linear array, where both gain and directivity are increased compared to an antenna system without directors. In some examples, different directors 106a, 106b are tuned to enhance directivity and gain at different frequencies within the bandwidth of the array 102 (e.g., one director 106a is tuned for higher gain and directivity at higher frequencies, and the other director 106b is tuned for higher gain and directivity at lower frequencies).

[0059] FIG. 11 illustrates an exemplary aircraft 1100 including a fuselage 1102, a wing 1104, and an aircraft structure 1150. Exemplary aircraft structures including or coupled to an antenna system include various structural components of the aircraft 1100, including, but not limited to, a bulkhead 1101, an aircraft skin 1103 (e.g., a skin panel), a wing spar 602, or a leading edge 1152 of the wing 1104. One or more components of the antenna system (e.g., the reflector 110) are integrated or combined with the aircraft structure in various configurations. In some embodiments, the antenna system 100 is mounted entirely on the surface of the aircraft structure 1150, while in other embodiments, the antenna system 100 is mounted within the interior of the aircraft structure. FIG. 11 further illustrates that the antenna system is configurable and positioned such that a desired directivity is aimed toward the waterline 1106 or the horizon 1108.

[0060] Exemplary Process Steps Method for making an antenna system 12 shows a method for making an antenna system, which includes the following steps:

[0061] Block 1200 represents obtaining or manufacturing an array of elements (e.g., a multi-tap antenna, a TCDA, a linear array, or a fed array). In one or more embodiments, the elements comprise conductors. An exemplary conductor includes a metal layer on a dielectric. In one or more further embodiments, the elements each comprise a dipole element.

[0062] Block 1202 represents coupling feed lines to the array. emitting radiation in response to an input signal being input to the dipole element via a feed line; or and outputting an output signal onto the feedline in response to the electromagnetic radiation being received at the multi-tap antenna.

[0063] Block 1204 represents placing a director in front of the array, where the director has a reactance that increases the directivity of the antenna system. In one or more embodiments, the director may be Reactive It comprises a printed circuit board or circuit with metal pads or tracks mated to a dielectric to form a load.

[0064] Block 1206 represents placing a reflector behind the array, where the reflector is configured to reflect radiation toward the director or array. In one or more embodiments, the reflector may be a second Reactive It comprises a printed circuit board or circuit with metal pads or tracks mated to a dielectric to form a load.

[0065] Block 1208 represents the end result, i.e., the antenna system. Exemplary, non-exclusive embodiments of the inventive subject matter according to the present disclosure are described in the following enumerated paragraphs (also with reference to FIGS. 1A, 1B, 2, 4A-4C, 5, and 6A, 8, 9, and 11).

[0066] A1. An antenna system (100) comprising an array (102) of conductors (104) coupled to a feedline (202) and a director (106) disposed in front of the array (102), the array (102) comprising: emitting electromagnetic radiation (113) in response to an input signal being input to the array (102) via the feed line (202); or outputting an output signal to the feed line in response to electromagnetic radiation being received at the array; The director (106) is connected to the conductor (104). Reactive a first complex impedance adjusted to increase the directivity (144) of the antenna system (100) by loading it; Reactive An antenna system (100) having a load (135).

[0067] A2. The antenna system (100) of paragraph A1 further comprises a reflector (110) arranged behind the array (102), the reflector (110) being configured so that a portion of the electromagnetic radiation (113) received by the reflector (110) and including the received electromagnetic radiation is reflected (119) toward the director (106).

[0068] A3. The reflector (110) is a second Reactive A load (141) is provided, The second Reactive The antenna system (100) of paragraph A2, wherein a load (141) has a second complex impedance that adjusts the reflection of the received electromagnetic radiation (113) directed toward the director (106).

[0069] A4. The reflector (110) comprises a printed circuit board (124); The printed circuit board (124) comprises conductor tracks (502); An antenna system (100) of paragraph A3, wherein the conductor track (502) has at least one of a thickness (506) or a meandering path (504) that varies as a function of position along the length (L3) of the reflector (110) to adjust the second complex impedance.

[0070] A5. The director (106) comprises a printed circuit board (124); The printed circuit board (124) includes a circuit; The circuit is Reactive One or more forming a load (135) Reactive The antenna system (100) of any one of paragraphs A1 to A4, having an impedance.

[0071] A6. The antenna system (100) of paragraph A5, wherein the circuit comprises a circuit element (401) configured to control the phase of the electromagnetic radiation (113) at various positions along the length (L1) of the array (102) so as to increase the directivity (144) by adjusting at least one of destructive interference or constructive interference of the electromagnetic radiation (113) at the various positions.

[0072] A7. One or more of the above Reactive The antenna system (100) of paragraph A5 or A6, wherein the impedance includes a capacitive reactance and an inductive reactance.

[0073] A8. The first Reactive The load (135) comprises an array of circuit elements (401), each of which: a first capacitor (C1), and a second capacitor (C2) in parallel with the coil (L); The antenna system (100) of any one of paragraphs A1 to A7, wherein the first capacitor (C1) is in series with the combination of the second capacitor (C2) and the coil (L).

[0074] A9. the conductors (104) are periodically arranged along the array (102) with a period P; The first Reactive The antenna system (100) of any one of paragraphs A1 to A8, wherein the load (135) comprises an array of the circuit elements (401) arranged at the period P along the length (L2) of the director (106).

[0075] A10. The method further comprises a first microstrip (126) comprising the array and a second microstrip (132) comprising the director (106), the first microstrip (126) comprising: the conductor (104), a conductive backplane (128); a first dielectric (130) disposed between the conductor (104) and the conductive backplane (128); and further comprising a plurality of loads (116), each of said loads (116) connecting one of said conductors (104a) to an adjacent one of said conductors (104b); The second microstrip (132) is Reactive a load (135); The first Reactive The load (135) comprises a plurality of conductive components (134) separated by one or more dielectric layers (402, 404); The antenna system (100) of any of paragraphs A1 to A9, wherein the plurality of conductive components (134) comprises at least one of a capacitance pad or a wire having an inductance.

[0076] A11. a third microstrip (138) with a reflector (110) disposed behind the array (102), the third microstrip (138) including the wires having at least one of a varying thickness (506) or a meandering path (504) that varies the inductance of the wires along a length (L3) of the third microstrip (138). Reactive The antenna system (100) of paragraph A10, comprising a load (141).

[0077] A12. The antenna system (100) of paragraph A10 or A11, wherein two or more of the first microstrip (126), the second microstrip (132), and the third microstrip (138) are parallel, coplanar, and have the same length.

[0078] A13. the distance (D1) between the array (102) and the director (106) is within 10% of λ / 4; the distance between the array (102) and the reflector (110) is within 10% of λ / 8; The antenna system (100) of any one of paragraphs A1 to A12, wherein λ is the longest wavelength of said electromagnetic radiation (113).

[0079] A14. The first Reactive The load (135) or the second Reactive At least one of the loads (141) the frequency of said electromagnetic radiation (113) in the range between 10 MHz and 10 GHz, and The antenna system of any one of paragraphs A1 to A13, wherein the directivity (144) of the antenna system (100) is adjusted as a function of M( 100).

[0080] A15. The antenna system (100) of any one of paragraphs A1 to A14, wherein the directivity (144) includes focusing the electromagnetic radiation (113) onto or from a sidewall (114) of the array (102) facing the director (106).

[0081] A16. The antenna system (100) of any one of paragraphs A1 to A15, wherein the director (106) is configured such that the directivity (144) includes concentrating the electromagnetic radiation (113) in an elevation direction away from or toward the horizontal (1108).

[0082] A17. The antenna system (100) of any one of paragraphs A1 to A16, wherein the array (102) comprises a tightly coupled dipole array (TCDA) or a multi-tap antenna (200).

[0083] A18. The conductors (104) each have a length (L4) within 10% of λ / 10; the conductors (104) are separated by a distance (d) within 10% of λ / 100; The antenna system (100) of any one of paragraphs A1 to A17, wherein λ is the longest wavelength of the electromagnetic radiation (113).

[0084] A19. The electric field generated by the electromagnetic radiation (113) in one of the conductors (104a) and experienced in the next adjacent one of the conductors (104b) is 1 / d 2 the near-field amplitude proportional to 1 / d 3 is proportional to Reactive the conductor (104) is capacitively coupled or coupled by short-range interaction of the electric field so as to have a short-range amplitude; The antenna system (100) of any one of paragraphs A1 to A18, wherein d is a distance separating said one of said conductors (104a) from said next adjacent one of said conductors (104b).

[0085] A20. an aircraft structure (1150); the aircraft structure (1150) comprises or is attached to the reflector (110); The antenna system (100) of any one of paragraphs A1 to A19, wherein the aircraft structure (1150) further includes a skin (1103), a wing spar (602), a bulkhead (1101), or a wing leading edge.

[0086] A21. An aircraft (1100) equipped with an antenna system (100) according to paragraph A1.

[0087] A22. The antenna system (100) of any of paragraphs A1 to A21, wherein the director (106) and the reflector (110) comprise passive elements.

[0088] A23. The antenna system (100) of any one of paragraphs A1 to A16, wherein the electromagnetic radiation (113) includes radio frequencies.

[0089] A24. The antenna system of any of paragraphs A1 to A18, wherein the directionality (144) focuses the energy of the electromagnetic radiation onto a sensor at the waterline or horizontal.

[0090] A25. The array (102), the director (106), and the reflector (110) are arranged across a conductive backplane (128) to improve gain by up to 6 dB. Reactive The antenna system (100) of any one of paragraphs A1 to A24, wherein the load is applied.

[0091] A26. The array (102), the director (106), and the reflector (110) are arranged such that when an active center dipole element comprising one of the conductors (104) in the array (102) is excited, the other dipole elements (comprising the other conductors (104)) are also excited, but at a given phase, their excitation fields increase in the horizontal direction and cancel above and below (up and down) the array. Reactive The antenna system (100) of any one of paragraphs A1 to A25, wherein the antenna system (100) is loaded.

[0092] A27. The antenna system (100) of any one of paragraphs A1 to A26, wherein the directivity (144) increases in the elevation direction (angle theta) but does not increase significantly in the azimuth direction, such that the electric field pattern comprises a cone having an elliptical cross section with a major axis along the elevation direction and a minor axis along the azimuth direction.

[0093] A28. The antenna system (100) of any of paragraphs A1 to A27, wherein the array includes a linear array of the conductors.

[0094] A29. The antenna system (100) of any of paragraphs A1 to A28, wherein the conductor (104) comprises a dipole element.

[0095] A30. The antenna system (100) of any of paragraphs A1 to A29, wherein the array (102) comprises a fed array.

[0096] A31. The antenna system (100) of any of paragraphs A1 to A29, wherein the array (102) includes a TCDA.

[0097] A32. The antenna system (100) of any one of paragraphs A1 to A29, wherein the array (102) comprises a plurality of loads (116), each of the loads (116) connecting one of the conductors (104a) to an adjacent one of the conductors (104b).

[0098] A33. The antenna system (100) of paragraph A32, wherein each of the loads (116) comprises a resistance or a resistance in series with a capacitance.

[0099] A34. The first Reactive The antenna system (100) of any one of paragraphs A1 to A33, wherein the load (135) comprises a capacitive strip (120) including a first metal layer on a first dielectric.

[0100] A35. The second Reactive The antenna system (100) of any one of paragraphs A3 to A34, wherein the load (141) comprises an inductive strip (122) including a second metal layer on a second dielectric.

[0101] A36. The first Reactive The antenna system (100) of any one of paragraphs A1 to A35, wherein the load (135) comprises at least one capacitor (C1) that includes a dielectric layer (404).

[0102] A37. The first Reactive The load (135) or the second Reactive The antenna system (100) of any one of paragraphs A1 to A36, wherein at least one of the loads (141) comprises a circuit on the dielectric layer (404) and / or a semiconductor.

[0103] A38. The antenna system (100) of paragraph A37, wherein the circuit comprises one or more discrete electrical components, one or more circuit elements (401), one or more conductor tracks (502), or one or more conductive pads.

[0104] How to use an antenna array FIG. 13 shows a method of using the antenna system.

[0105] Block 1300 represents transmitting and receiving radiation using an antenna array (eg, TCDA).

[0106] Block 1302 represents increasing the directivity of the antenna system using a director placed in front of the array and a reflector placed after the antenna array, in one or more embodiments the directivity is aimed towards the horizon or waterline.

[0107] conclusion This concludes the description of the preferred embodiments of the present disclosure. The foregoing description of the preferred embodiments has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure to the precise form disclosed. Many modifications and variations are possible in light of the above teachings. It is intended that the scope of coverage be limited not by this detailed description, but rather by the appended claims.

Claims

1. 1. An antenna system comprising an array of conductors coupled to a feedline and a director positioned in front of the array, the array comprising: emitting electromagnetic radiation in response to an input signal being input to the array via the feed line; or outputting an output signal onto the feed line in response to electromagnetic radiation being received at the array; 1. An antenna system, wherein the director comprises a first reactive load having a first complex impedance tuned to increase the directivity of the antenna system.

2. 10. The antenna system of claim 1, further comprising a reflector disposed behind the array, the reflector configured to receive and reflect a portion of electromagnetic radiation toward the director.

3. the reflector comprises a second reactive load; 3. The antenna system of claim 2, wherein the second reactive load has a second complex impedance that conditions electromagnetic radiation reflected from the reflector toward the director.

4. the reflector comprises a printed circuit board; the printed circuit board comprises conductor tracks; 4. The antenna system of claim 3, wherein the conductor tracks comprise at least one of a serpentine path or a line width that varies as a function of position along the length of the reflector, and wherein the second complex impedance is adjusted by the serpentine path or the varying line width.

5. the director comprises a printed circuit board; the printed circuit board includes a circuit; 5. The antenna system according to claim 1, wherein the circuit comprises one or more reactive elements that constitute the first reactive load.

6. 6. The antenna system of claim 5, wherein the circuitry comprises circuit elements configured to control the phase of the electromagnetic radiation at various locations along a length of the array so as to enhance the directivity by adjusting at least one of destructive interference or constructive interference of the electromagnetic radiation at the various locations.

7. 7. The antenna system according to claim 5, wherein the one or more reactive elements have a capacitive reactance and an inductive reactance.

8. The first reactive load comprises an array of unit cells, each of the unit cells having: a first capacitor; and a second capacitor in parallel with the coil; 8. An antenna system according to claim 1, wherein the first capacitor is in series with the combination of the second capacitor and the coil.

9. The method further includes a first microstrip comprising the array and a second microstrip comprising the director, the first microstrip comprising: the conductor, conductive backplane, a first dielectric disposed between the conductor and the conductive backplane; and further comprising a plurality of loads, each of the loads connecting one of the conductors to an adjacent one of the conductors; the second microstrip further comprises the first reactive load; the first reactive load comprises a plurality of conductive components separated by one or more dielectric layers; 9. The antenna system of claim 1, wherein the plurality of conductive components comprises at least one of conductive pads or wires having inductance.

10. a third microstrip having a reflector disposed behind the array; 10. The antenna system of claim 9, wherein the third microstrip includes a second reactive load, the second reactive load including the wire having at least one of a varying line width or a serpentine trajectory that varies the inductance of the wire along a length of the third microstrip.

11. the array is a linear array; 11. The antenna system of claim 10, wherein the first microstrip, the second microstrip, and the third microstrip are parallel, coplanar, and have the same length.

12. 12. An antenna system according to any preceding claim, wherein the directionality comprises the electromagnetic radiation being directed away from or towards a sidewall of the array.

13. 13. The antenna system of claim 1, wherein the director is configured such that the directivity includes concentrating the electromagnetic radiation at a horizontal angle in an elevation direction.

14. 14. The antenna system of claim 1, wherein the array comprises a tightly coupled dipole array (TCDA) or a multi-tap antenna.

15. further comprising an aircraft structure; the aircraft structure comprises or is attached to a reflector positioned behind the array; the reflector is configured to receive and reflect a portion of the electromagnetic radiation toward the director; The antenna system of claim 1 , wherein the aircraft structure further comprises a skin, a wing spar, a bulkhead, or a wing leading edge.

16. An aircraft equipped with an antenna system according to any one of claims 1 to 15.

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