Microwave component with at least one load integrated into the support substrate

Abstract

A microwave component (40), said component comprising: - at least one waveguide (42) comprising a propagation zone (48) of an electromagnetic wave, said propagation zone extending along a propagation axis; - a support substrate (44) of dielectric material adapted to ensure the mechanical rigidity of said component; - said support substrate comprising a first layer made of dielectric material having a first upper electrically conductive surface (44.1) and a first lower electrically conductive surface (44.2) respectively covering an upper and a lower face of said support substrate; - at least one absorption zone (47) extending into the support substrate to guide the propagation of electromagnetic waves from said waveguide into the substrate in order to absorb or attenuate the energy of the waves, said absorption zone being delimited by the first upper electrically conductive surface (44.1), the first lower electrically conductive surface (44.2) and two spaced lateral boundaries (46) designed to prevent the passage of an electromagnetic wave; - a feed element (49.1, 49.2) positioned at the entrance of said absorption zone (47) and configured to take at least a portion of the electromagnetic wave from said propagation zone (48) of said at least one waveguide and inject it into said absorption zone (47). Abstract figure: Figure 5.

Description

Title of the invention: Microwave component with at least one load integrated into the support substrate technical field

[0001] The present invention relates to the field of microwave components based on microwave transmission lines, and in particular to that of microwave components based on transmission lines integrated into the substrate or waveguide integrated into the substrate. Previous technique

[0002] In microwave and millimeter wave systems, it is known to use 3D rectangular metallic waveguides (RWGs) to fabricate high-performance microwave components. However, RWGs are bulky, expensive, and difficult to integrate into planar structures.

[0003] In order to reduce manufacturing costs and enable mass production, microwave components are made using planar technology.

[0004] Figure 1 shows an example of an embodiment of a transmission line formed by a microstrip 5 separated from a conductive layer 3 by a dielectric layer 2. The propagation zone 8 is located below the microstrip. The assembly can be supported by a support substrate 4.

[0005] Figure 2 presents another example of a transmission line embodiment A coplanar array 10 is formed by a conductive track 11 bordered on each side by a return line 12, 13. The propagation zone 18 is located beneath the central track 11, within a dielectric layer 15 sandwiched between the tracks and a conductive layer 16. Vias 16, 17 extend between the conductive layers through the dielectric layer 15 to define the pattern of the propagation zone. The entire assembly is supported by a support substrate 14.

[0006] However, these microwave components generate losses and leaks of energy through high-frequency radiation.

[0007] In order to improve the performance of microwave components while offering low-cost, highly integrated, compact and mass-produced microwave components, microwave components based on substrate integrated waveguide (SIW) technology have been proposed.

[0008] Figure 3 shows an illustration of an example of the structure of a waveguide SIW 20 is configured to guide an electromagnetic wave along a propagation axis XX. It comprises a central layer 21 made of a material The dielectric layer is of small thickness and consists of an upper electrically conductive layer 22 and a lower electrically conductive layer 23 covering the two opposite faces of the central dielectric layer 21. The three layers extend in an XY plane, defined by the propagation axis XX and a transverse axis YY orthogonal to the propagation axis XX. The upper conductive layer 22 and the lower conductive layer 23 are positioned at a distance from each other, on either side of the dielectric layer 21, in contact with the dielectric layer. Thus, the three layers are stacked along a Z-axis.

[0009] The conductive layers are made, for example, of copper. The dielectric layer is made, for example, of an epoxy resin.

[0010] The dielectric layer 21 also comprises a plurality of plated holes, each hole forming a via 26, 27 between the first and second conductive layers. The plurality of vias thus forms two distinct rows, spaced apart. Therefore, the component comprises a propagation zone 28 in the dielectric layer 21, delimited, according to its thickness, between the upper and lower conductive layers 22, 23 and, according to its width, between the plurality of plated holes. The propagation zone 28 extends along the propagation axis XX, corresponding to a zone in which the electromagnetic waves are confined. The pattern formed by the plurality of plated holes consequently defines the radio frequency function performed by the microwave component, which can be, for example, a transmission line, a filter, a coupler, an antenna, a power divider, or a power combiner.The component also includes a thick 24 support substrate.

[0011] This technology benefits from low manufacturing costs and is easily integrated into a printed circuit board-based system. The components generally have a very lightweight structure, while still allowing for high integration density within systems. Thus, such SIW components are more compact and less expensive than conventional rectangular waveguides.

[0012] Recently, in order to reduce the dielectric loss of the propagation medium while maintaining low cost and high integration, air-filled substrate integrated waveguide (AFSIW) or hollow waveguide technology has been proposed. Like SIW technology, AFSIW or hollow SIW is a multilayer structure based on PCB technology.

[0013] Figure 4 illustrates an example of the structure of an AFSIW waveguide 30. The structure of an AFSIW waveguide comprises an upper layer 31 of dielectric material and a lower layer 32 of dielectric material. The two faces of the upper dielectric layer 31 are each covered respectively by a conductive upper layer 33 and a lower layer A longitudinal cavity 38 is formed in the lower dielectric layer 32. The internal side walls 38.1, 38.3 and the lower wall 38.2 of the cavity are metallized. Thus, the component has a propagation zone 38 in the lower dielectric layer 32, delimited, according to its thickness, by the lower conductive layer 35 and the lower internal wall 38.2 of the cavity, and, according to its width, by the metallized internal side walls 38.1, 38.3 of the cavity. The propagation zone 38 extends along the propagation axis XX, corresponding to a zone in which the electromagnetic waves are confined. The pattern formed by the cavity therefore defines the radio frequency function performed by the microwave component, which can be, for example, a transmission line, a filter, a coupler, an antenna, a power divider, or a power combiner.The component may further comprise a dielectric substrate 34 which provides support for the assembly and increases its rigidity. Alternatively, the component is supported by the lower dielectric layer 32, which may have a suitable thickness.

[0014] However, the microwave components illustrated in Figures 1 to 4 are not entirely satisfactory. Indeed, when termination loads are required in a radio frequency circuit design, they are added externally or manually within the structure. The structure must then be manually shielded. Thus, the termination is not fully integrated and is therefore unsuitable for mass production. This solution also leads to an increase in the size of the structure due to the need for a mounting system, and the risk of efficiency loss due to radio frequency leakage from the external interfaces. The introduction of this additional step also increases production costs.

[0015] Furthermore, the inventors observe that in the structures of currently implemented microwave components, the main radio frequency function uses only a small percentage of the available printed circuit board volume. Indeed, the substrate, which constitutes a large part of the printed circuit boards, contributes solely to increasing the robustness of the overall structure. For example, as shown in Figures 1 to 4, whether using planar technology or technology with waveguides integrated into the dielectric layers, substrate layers 4, 14, 24, and 34 are not utilized. Their main function is to support the microwave component and make it rigid.

[0016] Consequently, there is a need to find a solution for easily integrating termination loads or absorbers into planar microwave components based on microwave transmission lines, and in particular into microwave components based on transmission lines integrated into the substrate or waveguide integrated into the substrate, without incurring additional manufacturing costs, while maintaining the performance required for these components. Summary

[0017] This disclosure improves the situation.

[0018] This disclosure relates to a microwave component, said component comprising: - at least one waveguide comprising a propagation zone for an electromagnetic wave, said propagation zone extending along a propagation axis; - a support substrate made of suitable dielectric material to ensure the mechanical rigidity of said component; - said support substrate comprising a first layer made of dielectric material having a first upper electrically conductive surface and a first lower electrically conductive surface covering respectively an upper face and a lower face of said support substrate; - at least one absorption zone extending into the support substrate to guide the propagation of electromagnetic waves from said waveguide into the substrate in order to absorb the energy of the waves or to attenuate the energy of the waves, said absorption zone being delimited by the first upper electrically conductive surface, the first lower electrically conductive surface and two spaced lateral boundaries suitable for preventing the passage of an electromagnetic wave; - a feed element positioned at the entrance of said absorption zone and configured to take at least a portion of the electromagnetic wave from said propagation zone of said at least one waveguide and to inject it into said absorption zone.

[0019] The features described in the following paragraphs may optionally be implemented independently of each other or in combination with each other.

[0020] The lateral boundaries of the absorption zone are formed by a plurality of metallized through holes extending through the support substrate to electrically connect the first upper electrically conductive surface and the first lower electrically conductive surface.

[0021] The plurality of metallized through holes defines a pattern having the shape of a meander.

[0022] The plurality of metallized through holes defines a pattern having the shape of a ring.

[0023] The first layer made of dielectric material has a thickness of between 0.2 mm and 10 mm, preferably between 0.5 mm and 6 mm.

[0024] According to one embodiment, said at least one waveguide comprises a second layer of dielectric material having a second electrically conductive upper surface and a second electrically conductive lower surface, said second electrically conductive lower surface being in electrical contact with said first electrically conductive upper surface of said support substrate, the propagation zone being defined in said second layer of dielectric material and delimited by the second electrically conductive upper surface, the second electrically conductive lower surface and by a plurality of through-metallized holes extending through said second layer of dielectric material.

[0025] According to one embodiment, said power supply element comprises a first slot made in the second lower conductive surface and a second slot made in the first upper conductive surface, the two slots being aligned and arranged opposite the entrance of the absorption zone.

[0026] Preferably, the power element comprises a set of metallized steps made in the support substrate, at the interface between the support substrate and the first lower conductive surface.

[0027] According to another embodiment, said at least one waveguide comprises a second layer of dielectric material having a second electrically conductive upper surface and a second electrically conductive lower surface, said second electrically conductive lower surface being in electrical contact with said first electrically conductive upper surface of said support substrate, said propagation zone comprises an internal cavity made in the support substrate, the side walls and the lower wall of said cavity being metallized, the propagation zone being delimited by the second electrically conductive lower surface of the second layer of dielectric material and the metallized walls of the cavity.

[0028] According to one embodiment, the feed element includes a hollow area made in the support substrate, said hollow area being formed from an extension of one end of the internal cavity of the waveguide.

[0029] Preferably, the hollow zone comprises a first end forming an interface with the end of the cavity and a second end in the form of a point penetrated into the absorption zone of the substrate.

[0030] Preferably, the end of the cavity located at the interface with the first end of the hollow zone includes a set of metallized steps to achieve impedance matching between the cavity and the absorption zone.

[0031] According to another embodiment, said feed element includes at least one slot made in one of the walls of the internal cavity of the waveguide. Brief description of the drawings

[0032] Other features, details and advantages will become apparent from reading the detailed description below and from analyzing the accompanying drawings, in which: Fig. 1

[0033] [Fig.1] Fig.1 is a sectional view of a microwave component comprising a microruban transmission line, in a plane orthogonal to the propagation axis XX; Fig. 2

[0034] [Fig.2] Fig.2 is a sectional view of a microwave component comprising a coplanar transmission line, in a plane orthogonal to the propagation axis XX;

[0035] Fig. 3

[0036] [Fig.3] The [Fig.3] is a sectional view of a SIW type microwave component, in a plane orthogonal to the propagation axis XX; Fig. 4

[0037] [Fig.4] Fig.4 is a sectional view of a microwave component of the type AFSIW, in a plane orthogonal to the propagation axis XX; Fig. 5

[0038] [Fig.5] Fig.5 is a sectional view of a microwave combiner component / isolated power divider according to an embodiment of the invention, in a plane orthogonal to the propagation axis XX; Fig. 6

[0039] [Fig.6] [Fig.6] presents respectively: (a) a top view of the second upper conductive surface of the microwave component of [Fig.5], (b) a top view of the second lower conductive surface, and (c) a top view of the first upper conductive surface; Fig. 7A

[0040] [Fig.7A] Fig.7A represents the amplitude of the electric field in the microwave component operating in a normal operating configuration, with the signal applied to port 1 and the output signal at ports 2 and 3; Fig. 7B

[0041] [Fig.7B] Fig.7B represents the amplitude of the electric field in the microwave component operating in a situation in which a part representing approximately 50% of the signal entering port 2 is taken at the junction and injected into the absorption zone made in the lower substrate layer, port 3 is thus isolated and protected; Fig. 7C

[0042] [Fig.7C] Fig.7C represents the amplitude of the electric field in the microwave component operating in a situation in which a part representing approximately 50% of the signal entering port 3 is taken at the junction and injected into the absorption zone made in the lower substrate layer, port 2 is thus protected; Fig. 7D

[0043] [Fig.7D] Fig.7D represents a view of the amplitude of the electric field in the absorption zone made in the lower substrate layer from the lower face of the microwave component; Fig. 8

[0044] [Fig.8] Fig.8 is a sectional view of a power microwave coupler according to another embodiment of the invention, in a plane orthogonal to the propagation axis XX; Fig. 9

[0045] [Fig.9] [Fig.9] presents respectively: (a) a top view from the surface (b) a top view from the top surface of the upper conductive layer of the upper dielectric layer of the coupler of [Fig.8], (c) a top view from the top surface of the lower conductive layer of the upper dielectric layer of the coupler of [Fig.8], and (c) a top view from the top surface of the upper conductive layer of the lower dielectric layer of the microwave component of [Fig.8]; Fig.1OA

[0046] [Fig.1OA] The [Fig.1OA] represents the amplitude of the electric field in the power coupler of the [Fig.8] operating in a normal operating configuration, with the signal applied to port 1 and the output signal at ports 2 and 3; Fig. 1OB

[0047] [Fig.1OB] Fig.1OB represents the amplitude of the electric field in the microwave component operating in a situation in which a part representing approximately 50% of the signal from port 3 is taken at port 4 and injected into the absorption zone made in the lower substrate layer, port 2 is thus isolated and protected; Fig. 1OC

[0048] [Fig.1OC] Fig.1OC represents the amplitude of the electric field in the microwave component operating in a situation in which a part representing approximately 50% of the signal from port 2 is taken at port 4 and injected into the absorption zone made in the lower substrate layer, port 3 is thus isolated and protected; Fig. lOD

[0049] [Fig.1OD] The [Fig.1OD] represents a view of the amplitude of the electric field in the absorption zone made in the lower substrate layer from the lower face of the microwave component; Fig. II

[0050] [Fig. 11] The [Fig. 11] is a sectional view of a microwave component made using hollow SIW technology integrated according to an embodiment of the invention, in a plane orthogonal to the propagation axis XX; Fig. 12

[0051] [Fig. 12] The [Fig. 12] represents a perspective and top view of a Y-shaped cavity in a hollow SIW microwave component with an absorption zone integrated into the support substrate according to an embodiment of the invention; Fig. 13A

[0052] [Fig.13A] The [Fig.13A] represents the amplitude of the electric field in the microwave component of the [Fig. 12] operating in a normal use configuration, with the signal applied to port 1 and the output signal at ports 2 and 3; Fig. 13B

[0053] [Fig.13B] Fig.13B represents the amplitude of the electric field in the microwave component operating in a situation in which part of the signal energy from port 3 is taken at the slot and injected into the absorption zone made in the lower substrate layer, thus protecting port 2; Fig. 13C

[0054] [Fig.13C] Fig.13C represents the amplitude of the electric field in the microwave component operating in a situation in which part of the signal energy from port 2 is taken at the junction and injected into the absorption zone made in the lower substrate layer, port 3 is thus protected; Fig. 14

[0055] [Fig. 14] The [Fig. 14] represents a top perspective view of a Y-shaped cavity of a hollow SIW microwave component with an absorption zone integrated into the support substrate according to a variant of the [Fig. 12] and an enlarged view of the central region of the waveguide; Fig. 15A

[0056] [Fig. 15A] Fig. 15A represents the amplitude of the electric field in the microwave component of Fig. 14 operating in a configuration normal use, with the signal applied to port 1 and the outgoing signal at ports 2 and 3; Fig. 15B

[0057] [Fig.15B] Fig.15B represents the amplitude of the electric field in the microwave component operating in a situation in which the signal comes from port 3 and part of the energy of the signal from port 3 is taken at the central area via the slot and injected into the absorption area made in the support substrate layer, port 2 is thus isolated and protected; Fig. 15C

[0058] [Fig.15C] Fig.15C represents the amplitude of the electric field in the microwave component operating in a situation in which the signal comes from port 2 and part of the energy of the signal from port 2 is taken at the central area via the slot and injected into the absorption area made in the lower substrate layer, port 3 is thus isolated and protected. Fig. 16A

[0059] [Fig. 16A] Fig. 16A is a top perspective view of a channel-shaped cavity of a hollow SIW microwave component without the top layers, incorporating an absorption zone in the support substrate according to another embodiment, the end of the channel forming a feed element opening into an absorption zone integrated in the dielectric support substrate of the component; Fig. 16B

[0060] [Fig.lôB] The [Fig.lôB] represents an enlarged top view of the impedance and supply matching zone between the cavity and the absorption zone of the [Fig.l6A]; Fig. 17

[0061] [Fig. 17] The [Fig. 17] is a representation of the amplitude of the electric field in the power element and the absorption zone of the [Fig.10A] when a signal from a port 1 is injected into the absorption zone. Description of the implementation methods

[0062] The present invention relates to a microwave component comprising a waveguide including an electromagnetic wave propagation zone, the zone extending along a propagation axis in at least one dielectric material to propagate a signal between two ports.

[0063] In the context of the present invention, the microwave component or microwave transmission line refers to any component requiring the implementation of a radio frequency load. The microwave component of the present invention may be for example, a coupler, a filter, an antenna, a divider, a combiner, or even an isolator.

[0064] For the purposes of this disclosure, the term "radio frequency load" or "termination load" refers to elements used in a microwave transmission component to absorb energy and prevent RF signals from reflecting back from an open or unused port. Ports are typically terminated with a load whose characteristic impedance is the same as that of the transmission line. Any multi-port RF system, where not all ports are in use, must be terminated so that any signal incident on those ports is absorbed. If a port is not terminated, signals can reflect back into the system, which can introduce distortion and other undesirable effects. Loads are used in couplers, hybrids, isolators, test equipment, and in systems where a port must be terminated. There are three main types of RF terminations: coaxial, waveguide, and chip.In this disclosure, the charges are used to terminate the waveguide ports.

[0065] Within the scope of the present invention, the microwave component can be made using planar technology for any type of planar transmission line and covers in particular microstrip components and coplanar components illustrated in Figures 1 and 2. The components can also be made using stripline technology.

[0066] In the context of the present invention, the microwave component can be implemented using substrate integrated waveguide (SIW) technology. In the following description, such components will be referred to as "SIW components".

[0067] Within the scope of the present invention, the microwave component can be implemented using hollow waveguide technology integrated into the substrate. In the following description, such components will be referred to as hollow SIW.

[0068] According to embodiments of the invention, the microwave component further comprises: - a support substrate made of a suitable dielectric material to ensure the mechanical rigidity of said component, the support substrate having an electrically conductive upper surface and an electrically conductive lower surface covering one upper and one lower face of the support substrate; - an absorption zone extending into the support substrate to guide the propagation of electromagnetic waves from the waveguide into the substrate in order to absorb or attenuate the energy of the waves; and - a power element positioned at the entrance of said absorption zone and configured to draw at least a fraction of the electromagnetic field from of said propagation zone at least one waveguide and to inject it into said absorption zone.

[0069] Thus, thanks to the direct integration of this absorption zone into the substrate, it is no longer necessary to manually add the RF load to the outside or inside the component structure and to manually shield the structure. Such a component can be adapted for mass production and helps to limit production costs. Furthermore, integrating the load into the substrate eliminates the need for a mounting system to attach the load to the component structure, thereby reducing the size of the structure. The absence of interfaces also helps to limit the risks of loss of efficiency and electromagnetic compatibility due to radio frequency leakage.

[0070] According to another technical advantage, the integration of the absorption zone into the substrate thus makes it possible to exploit the substrate which represents a large part of the printed circuits.

[0071] An example of a first embodiment of a microwave component 40 according to the invention is illustrated in [Fig.5].

[0072] The microwave component 40 is here of the type with a guide integrated into the substrate SIW.

[0073] The component 40 includes a waveguide 42 suitable for guiding an electromagnetic wave along at least one propagation axis, the electromagnetic wave having a predetermined wavelength, a support substrate 44 made of dielectric material suitable for ensuring the mechanical rigidity of the component, an absorption zone 47 extending into the support substrate to guide the propagation of electromagnetic waves from the waveguide into the substrate in order to absorb the energy of the waves or to attenuate the energy of the waves, and a power element 49.1, 49.2 positioned at the entrance of the absorption zone and configured to take at least a fraction of the electromagnetic wave from the propagation zone and to inject it into the absorption zone.

[0074] The support substrate comprises a first layer 44 of dielectric material extending in an XY plane. The first layer 44 has a first electrically conductive upper surface 44.1 and a first electrically conductive lower surface 44.2.

[0075] The waveguide 42 comprises a second layer of dielectric material 41 in which a propagation zone 48 is defined. The second layer of dielectric material 41 extends in the XY plane. The second layer of dielectric material has a second electrically conductive upper surface 41.1 and a second electrically conductive lower surface 41.2.

[0076] The first layer 44 and the second layer 41 are arranged at a distance from each other, on either side of the second lower electrically conductive surface 41.2 and the first electrically conductive upper surface 44.1 which are in contact.

[0077] Thus, the first layer 44 and the second layer 41 form a stack.

[0078] Electrically conductive surfaces are coatings made of a metallic material, for example copper.

[0079] The first and second layers are made of a dielectric material, for example an epoxy resin.

[0080] The propagation zone 48 corresponds to a zone of the waveguide in which the electromagnetic wave is confined during its propagation in the waveguide 42.

[0081] The waveguide 42 comprises a plurality of through-holes metallized 43 extending along a vertical axis ZZ orthogonal to the XY plane, to electrically connect the second lower electrically conductive surface 41.2 and the second upper electrically conductive surface 41.1 through the second layer 4L. Each metallized hole thus forms a via between the second upper conductive surface 41.1 and the second lower conductive surface 41.2.

[0082] The vias are arranged along a propagation axis, in two separate rows, at a distance from each other.

[0083] The distance between two successive vias of the same row is less than the smallest wavelength of the electromagnetic waves intended to propagate in the waveguide, for example less than or equal to one fifth of the smallest wavelength of the waves intended to propagate in the waveguide.

[0084] The propagation zone 48 is thus delimited, according to the thickness, by the second upper conductive surface 41.1, the second lower conductive surface 41.2, and according to the width, by the two rows of vias arranged on either side of a propagation axis.

[0085] The pattern formed by the vias defines the RF function performed by the microwave component.

[0086] Figure 6 illustrates an example of a waveguide propagation zone configured to perform the combiner / splitter function. View (a) is a top view of the second upper conductive surface 41.1 of the microwave component. The plated-through holes are arranged to form a T-shaped propagation zone. More specifically, the vias are arranged to form a first propagation zone 48.1 extending between port 1 and the combining zone 48.4 along a transverse propagation axis YY, a second propagation zone 48.2 extending between port 2 and the combining zone 48.4 along a longitudinal propagation axis XX, and a third propagation zone 48.3 extending between port 3 and the combining zone 48.4 along the longitudinal propagation axis XX.

[0087] The absorption zone 47 is defined in the support substrate and corresponds to a zone in which the electromagnetic wave is absorbed or attenuated during its propagation. The absorption zone is delimited, according to its thickness, by the first upper electrically conductive surface 44.1 and the first lower electrically conductive surface 44.2, and according to its width, by two spaced lateral boundaries 46.

[0088] According to one embodiment, the spaced lateral boundaries 46 of the absorption zone are formed by a plurality of metallized through holes which extend along a vertical axis ZZ orthogonal to the XY plane, through the support substrate 44 to electrically connect the first upper electrically conductive surface 44.1 and the first lower electrically conductive surface 44.2.

[0089] The metallized holes 46 are arranged along a propagation axis, in two separate rows, spaced apart from each other.

[0090] The distance between two successive plated holes in the same row is less than the shortest wavelength of the electromagnetic waves intended to propagate in the support substrate. Each plated hole here, for example, has a cylindrical shape. According to an alternative, it may have a rectangular shape. The plated holes locally modify the boundary conditions in the substrate 44 that constrain wave propagation in the support substrate 44.

[0091] The pattern of the absorption zone can be adapted so that the length of the absorption zone is sufficient to absorb the electromagnetic wave. In view (c) of [Fig. 6], which is a top view of the first upper conductive surface 44.1 of the microwave component, the pattern formed by the metallized holes defines a meander in which the electromagnetic wave will be absorbed or attenuated progressively during its propagation.

[0092] With reference to [Fig.5], the feed element comprises a first slot 49.1 made in the second lower conductive surface 41.2 and a second slot 49.2 made in the first upper conductive surface 44.1, the two slots being aligned and arranged opposite the combining area 48.4 in order to be able to take at least a fraction of the electromagnetic wave from the electromagnetic waveguide.

[0093] Preferably, the dimension of the first slot 49.1 is substantially smaller than that of the second slot 49.2, or vice versa, to ensure alignment between the first and second slots and thus avoid a situation where misalignment between the two slots leads to obstruction of one of them. The two slots are positioned opposite the entrance of the absorption zone 47, as shown in view (c) of [Fig. 6]. The function of the two slots is to to take at least a fraction of the electromagnetic wave coming from the propagation zone 48 and to inject it into the absorption zone 47.

[0094] The operation of the microwave component of combiner 40 of [Fig.5] will now be described, with reference to Figures 7A-7D which represent the amplitude of the electric field in the microwave component.

[0095] Figure 7A shows normal operation of the microwave component. The signal is injected into port 1 of the combiner / splitter component. The signal propagates through the first propagation zone to the central zone and then splits into two signals which propagate respectively through the second propagation zone to exit via port 2 and through the third propagation zone to exit via port 3.

[0096] Figure 7B represents the amplitude of the electric field in the microwave component operating in a situation where a portion of the signal entering port 2 is taken from the central area by the coupling element, namely slots 49.1, 49.2, and injected into the absorption zone formed in the lower substrate layer. Thus, the leakage signal is strongly canceled in the central area, and port 3 is thereby isolated and protected.

[0097] Figure 7C represents the amplitude of the electric field in the microwave component operating in a situation where a portion of the signal entering port 3 is taken from the central area by the power supply element and injected into the absorption zone in the lower substrate layer. Thus, the leakage signal is strongly canceled in the central area, and port 2 is thereby isolated and protected.

[0098] Figure 7D shows a view of the electric field amplitude in the absorption zone in the lower substrate layer from the underside of the microwave component. It can be seen that the field amplitude gradually decreases during wave propagation through the absorption zone until it is completely canceled out.

[0099] Figure 8 represents a variant of the embodiment shown in Figure 5. The microwave component of Figure 8 differs from that of Figure 5 in that the via pattern enables a coupling function. The power supply element further includes an impedance matching element 55 positioned at the input of the absorption region.

[0100] The microwave component 50 is here of the SIW substrate-integrated waveguide type.

[0101] The component 50 comprises a waveguide 52 adapted to guide an electromagnetic wave along at least one propagation axis, a support substrate 54 made of a suitable dielectric material to ensure the mechanical rigidity of the component, and an absorption zone 57 extending into the support substrate to guide the propagation of electromagnetic waves from the waveguide into the substrate in order to absorb or attenuate wave energy, and a feed element 59.1, 59.2, 55 positioned at the entrance of the absorption zone and configured to take at least a fraction of the electromagnetic wave from the propagation zone and inject it into the absorption zone.

[0102] The support substrate comprises a first layer 54 of dielectric material extending in an XY plane. The first layer 54 has a first electrically conductive upper surface 54.1 and a first electrically conductive lower surface 54.2.

[0103] The waveguide 52 includes a second layer of dielectric material 51 in which a propagation zone 58 is defined. The second layer of dielectric material 51 extends in the XY plane. The second layer of dielectric material has a second electrically conductive upper surface 51.1 and a second electrically conductive lower surface 51.2.

[0104] The first layer 54 and the second layer 51 are arranged at a distance from each other, on either side of the second lower electrically conductive surface 51.2 and the first upper electrically conductive surface 54.1 which are in contact.

[0105] Thus, the first layer 54 and the second layer 51 form a stack.

[0106] The propagation zone 58 corresponds to a zone of the waveguide in which is confined the electromagnetic wave during its propagation in the waveguide 42.

[0107] The waveguide 52 comprises a plurality of through-holes metallized 53 extending along a vertical axis ZZ orthogonal to the XY plane, to electrically connect the second lower electrically conductive surface 51.2 and the second upper electrically conductive surface 51.1 through the second layer 51. Each metallized hole thus forms a via between the second upper conductive surface 51.1 and the second lower conductive surface 51.2.

[0108] The propagation zone 58 is thus delimited, according to the thickness, by the second upper conductive surface 51.1, the second lower conductive surface 51.2, and according to the width, by the two rows of vias arranged on either side of a propagation axis.

[0109] Figure 9 illustrates an example of a waveguide propagation zone configured to perform the coupler function. View (a) is a top view of the second upper conductive surface 51.1 of the microwave component. The component has a first propagation zone 58.1 extending between port 1 and port 2 and a second propagation zone 58.2 extending between port 4 and port 3. The two propagation zones are thus formed by three substantially parallel rows of vias. The middle row has a central zone devoid of vias, allowing coupling to be established between the first and second propagation zones.

[0110] The absorption zone 57 is defined in the support substrate and corresponds to a zone in which the electromagnetic wave is absorbed or attenuated during its propagation. The absorption zone is delimited, according to its thickness, by the first upper electrically conductive surface 54.1 and the first lower electrically conductive surface 54.2, and according to its width, by two spaced lateral boundaries 56.

[0111] According to one embodiment, the spaced lateral boundaries 56 of the absorption zone are formed by a plurality of metallized through holes which extend along a vertical axis ZZ orthogonal to the XY plane, through the support substrate 54 to electrically connect the first upper electrically conductive surface 54.1 and the first lower electrically conductive surface 54.2.

[0112] The metallized holes 56 are arranged along a propagation axis, in two separate rows, spaced apart from each other.

[0113] In view (c) of [Fig. 9], which is a top view of the first upper conductive surface 54.1 of the microwave component, the plated holes form a "C" pattern in which the electromagnetic wave will be progressively absorbed or attenuated during its propagation. The absorption area can be of different shapes depending on the available volume in the support substrate.

[0114] The feed element comprises a first slot 59.1 made in the second lower conductive surface 51.2 and a second slot 59.2 made in the first upper conductive surface 54.1, the two slots being aligned and arranged opposite the port 4 so as to be able to take at least a fraction of electromagnetic background from the electromagnetic waveguide 52. In other words, the port 4 which is an unused port is connected to the absorption area which is located in the support substrate 54.

[0115] The two slits have the function of collecting here all the energy carried by the electromagnetic wave coming from the propagation zone 58 and injecting it into the absorption zone 57.

[0116] According to one embodiment, the power supply element further comprises an impedance matching element 55 in the form of a set of metallized steps formed in the support substrate at the entrance to the absorption zone. The slots and the metallized steps may be opposite each other.

[0117] The operation of the microwave component of coupler 50 of [Fig.8] will now be described, with reference to Figures 10A-10D which represent the amplitude of the electric field in the microwave component.

[0118] Figure 10A shows normal operation of the microwave component. The signal is injected into port 1 of the combiner / splitter component. The signal propagates in the first propagation zone between port 1 and port 2 and in the second propagation zone between port 1 and port 3.

[0119] Figure 10B represents the amplitude of the electric field in the microwave component operating in a situation where a representative portion of 50% of the signal entering port 3 is taken at port 4 by the power supply element and injected into the absorption zone in the lower substrate layer. Thus, the leakage signal is strongly canceled at the coupling zone, and port 2 is thereby isolated and protected.

[0120] Figure [1OC] represents the amplitude of the electric field in the microwave component operating in a situation where a representative portion of 50% of the signal entering port 2 is taken at port 4 by the power supply element and injected into the absorption zone in the lower substrate layer. Thus, the leakage signal is strongly canceled at the coupling zone, and port 3 is thereby isolated and protected.

[0121] Fig. 1OD shows a view of the electric field amplitude in the C-shaped absorption zone produced in the lower substrate layer from the underside of the microwave component. It can be seen that the field amplitude gradually decreases during wave propagation through the absorption zone until it is completely canceled out.

[0122] Fig. 11 represents a second embodiment of a component 60 according to the invention.

[0123] The microwave component 60 can be, for example, a filter, an antenna, a coupler, a combiner, a divider or an isolator.

[0124] The microwave component 60 is of the hollow waveguide type integrated into the substrate or hollow SIW.

[0125] The component 60 includes a waveguide 62 suitable for guiding an electromagnetic wave along at least one propagation axis, a support substrate 64 made of dielectric material suitable for ensuring the mechanical rigidity of the component, an absorption zone 67 extending into the support substrate to guide the propagation of electromagnetic waves from the waveguide into the substrate in order to absorb the energy of the waves or to attenuate the energy of the waves, and a power element 69 positioned at the entrance of the absorption zone and configured to take at least a portion of the electromagnetic wave from the propagation zone and to inject it into the absorption zone.

[0126] The support substrate comprises a first layer 64 of dielectric material extending in an XY plane. The first layer 64 has a first surface upper electrically conductive surface 64.1 and a first lower electrically conductive surface 64.2.

[0127] The waveguide 62 includes a second layer of dielectric material 61. The second layer of dielectric material 61 extends in the XY plane. The second layer of dielectric material has a second electrically conductive upper surface 61.1 and a second electrically conductive lower surface 61.2.

[0128] The first layer 64 and the second layer 61 are arranged at a distance from each other, on either side of the second lower electrically conductive surface 61.2 and the first upper electrically conductive surface 64.1 which are in contact.

[0129] Thus, the first layer 64 and the second layer 61 form a stack.

[0130] The propagation zone 68 corresponds to a zone of the waveguide in which is confined the electromagnetic wave during its propagation in the waveguide 62.

[0131] The waveguide 62 comprises an internal cavity 63 formed in the support substrate. The side walls 68.1, 68.2 and the lower wall 68.3 of said cavity are metallized. The internal cavity is delimited by the second lower electrically conductive surface 61.2 and the metallized walls of the cavity.

[0132] The propagation zone 68 is thus delimited, according to the thickness, by the second lower conductive surface 61.2 and the lower metallized wall of the cavity, according to the width, by the two metallized lateral walls of the cavity.

[0133] The internal cavity 63 can be filled with a fluid having a dielectric constant that may differ from the dielectric constant of the substrate. The fluid is, for example, air or a vacuum. Alternatively, if the internal cavity 63 defines a sealed volume, it is filled with nitrogen or is empty of fluid.

[0134] The absorption zone 67 is defined in the support substrate and corresponds to a zone in which the electromagnetic wave is absorbed or attenuated during its propagation. The absorption zone is delimited, according to its thickness, by the first upper electrically conductive surface 64.1 and the first lower electrically conductive surface 64.2, and according to its width, by two spaced lateral boundaries 66.

[0135] According to one embodiment, the spaced lateral boundaries 66 of the absorption zone are formed by a plurality of metallized through holes which extend along a vertical axis ZZ orthogonal to the XY plane, through the support substrate 64 to electrically connect the first upper electrically conductive surface 64.1 and the first lower electrically conductive surface 64.2. The metallized holes 66 are arranged along a propagation axis, in two separate rows, spaced apart from each other.

[0136] According to the example illustrated in [Fig. 11], the feed element here comprises a slot 69 made in the lower wall 68.3 of the cavity 68 to take a portion of the electromagnetic wave from the waveguide 62 and inject it into the absorption zone 67. According to another embodiment, the slot 69 can be made in one of the side walls 68.1, 68.2 of the cavity 68. The number of slots is not limiting.

[0137] [Fig.12] illustrates an example of an embodiment of [Fig.11].

[0138] The microwave component 80 can be a combiner or divider.

[0139] The microwave component 80 is of the hollow waveguide type integrated into the substrate or hollow SIW.

[0140] The component 80 includes a waveguide 82 suitable for guiding an electromagnetic wave along at least one propagation axis and a support substrate made of suitable dielectric material to ensure the mechanical rigidity of the component, an absorption zone 87 extending in the support substrate to guide the propagation of electromagnetic waves from the waveguide into the substrate in order to absorb the energy of the waves or to attenuate the energy of the waves, and a power element 89 positioned at the entrance of the absorption zone and configured to take at least a fraction of the electromagnetic wave from the propagation zone and to inject it into the absorption zone.

[0141] The waveguide 82 here includes an internal cavity 83 in the shape of a "Y". It has a first propagation zone 88.1 which extends between port 1 and a central zone 88.4, a second propagation zone 88.2 which extends between the central zone 88.4 and port 2 and a third propagation zone 88.3 which extends between the central zone 88.4 and port 3.

[0142] The absorption zone 87 is defined in the support substrate and corresponds to a zone in which the electromagnetic wave is absorbed or attenuated during its propagation.

[0143] Figure 12 shows a top view of the cavity located beneath the first upper conductive surface of the microwave component, showing a view of the Y-shaped cavity and the support substrate 84. The absorption zone 87 comprises a plurality of metallized holes 86 forming a meander in which the electromagnetic wave will be absorbed or attenuated progressively during its propagation. The absorption zone forms a meander to reduce its dimensions. It may be noted that here, the absorption zone is larger than in previous examples to accommodate the higher signal power.

[0144] The feed element includes a slot 89 formed in the lower wall of the cavity 83 to take a fraction of the electromagnetic wave from the waveguide and inject it into the absorption zone. The slot 89 is located here at the central junction zone 88.4 of the Y-shaped waveguide.

[0145] The operation of the microwave component 80 of [Fig. 12] will now be described, with reference to Figures 13A-13C which represents the amplitude of the electric field in the microwave component.

[0146] Figure 13A represents the amplitude of the electric field in the microwave component of Figure 12 operating in a normal operating configuration. The signal is injected into port 1 and exits at ports 2 and 3.

[0147] Fig. 13B represents the amplitude of the electric field in the microwave component operating in a situation in which part of the signal energy from port 3 is taken at slot 89 and injected into the absorption zone made in the lower substrate layer, port 2 is thus isolated and protected.

[0148] Fig. 13C represents the amplitude of the electric field in the microwave component operating in a situation in which part of the signal energy from port 2 is taken at slot 89 and injected into the absorption zone made in the lower substrate layer, port 3 is thus isolated and protected.

[0149] Fig. 14 represents a variant of the embodiment example of Fig. 12.

[0150] The microwave component 90 can be a combiner or a divider.

[0151] The microwave component 90 is of the type with a hollow waveguide integrated into the substrate or SIW hollow.

[0152] The component 90 includes a waveguide 92 suitable for guiding an electromagnetic wave along at least one propagation axis and a support substrate made of suitable dielectric material to ensure the mechanical rigidity of the component, an absorption zone 97 extending into the support substrate to guide the propagation of electromagnetic waves from the waveguide into the substrate in order to absorb the energy of the waves or to attenuate the energy of the waves, and a power element 99 positioned at the entrance of the absorption zone and configured to take at least a fraction of the electromagnetic wave from the propagation zone and to inject it into the absorption zone.

[0153] The waveguide 92 includes a metallized internal cavity 93 in the shape of a "Y". It has a first propagation zone 98.1 extending between port 1 and a central zone 98.4, a second propagation zone 98.2 extending between the central zone 98.4 and port 2, and a third propagation zone 98.3 extending between the central zone 98.4 and port 3.

[0154] The absorption zone 97 is defined in the support substrate and corresponds to a zone in which the electromagnetic wave is absorbed or attenuated during its propagation.

[0155] Figure 14 shows a top view of the cavity 93 located below the first upper conductive surface of the microwave component, showing a view of the Y-shaped cavity 93 integrated into the support substrate 94. The absorption zone 97 is defined by the plated holes 96, which here form a ring in which the electromagnetic wave will be absorbed or attenuated progressively during its propagation. In the example shown in Figure 14, the ring is centered substantially on the central junction zone 98.4 of the Y-shaped waveguide. The ring shape advantageously reduces the absorption zone area by a factor of two (2) compared to an S-shaped shape of Figure 14.

[0156] The feed element includes a slot 99 made in the lower bottom wall of the cavity 93 to take a fraction of the electromagnetic wave from the waveguide and inject it into the absorption zone.

[0157] The operation of the microwave component 90 of [Fig. 14] will now be described, with reference to Figures 15A-15C which represents the amplitude of the electric field in the microwave component.

[0158] Figure 15A represents the amplitude of the electric field in the microwave component of Figure 14 operating in a normal operating configuration of a divider. The signal is injected into port 1 and exits at ports 2 and 3.

[0159] Fig. 15B represents the amplitude of the electric field in the microwave component operating in a situation in which the signal comes from port 3 and part of the energy of the signal from port 3 is taken at the slot 99 and injected into the absorption zone made in the lower substrate layer, port 2 is thus isolated and protected.

[0160] Fig. 15C represents the amplitude of the electric field in the microwave component operating in a situation in which the signal comes from port 2 and part of the energy of the signal from port 2 is taken at the slot 99 and injected into the absorption zone made in the lower substrate layer, port 3 is thus isolated and protected.

[0161] Figures 16A and 16B show another embodiment of a hollow SIW electronic component whose waveguide 72 includes a channel integrated into the component's support substrate 74. Figure 16A shows only a top view of the channel 72 located below the first upper conductive surface of the support substrate. The absorption zone 76 is defined by the plated-through holes and forms a "U" pattern in which the electromagnetic wave will be progressively absorbed or attenuated during its propagation.

[0162] In this embodiment, the feed element 79 includes a non-metallized hollow area formed by the extension of one end of the channel which opens into the support substrate 74. This hollow area thus comprises One end interfaces with the end of the waveguide channel, and the other end is a pointed tip that penetrates the absorption zone 76. To achieve impedance matching between the air-filled cavity 73 of the channel and the dielectric absorption zone 76, a series of metallized steps 78 is formed at the channel end. The hollow area or extension of the channel end is not metallized and can take various geometric forms. The boundary between the channel and the inlet of the absorption zone is marked by a row of vias 75.

[0163] In the example shown here, each of the boundaries to define the absorption zone is formed by two rows of metallized holes instead of a single row of metallized holes in order to ensure better electromagnetic shielding of the absorption zone.

[0164] The operation of the termination charge microwave component of [Fig. 10A] will now be described, with reference to [Fig. 17] which represents the amplitude of the electric field in the microwave component.

[0165] Fig. 17 represents a view of the amplitude of the electric field in the U-shaped absorption zone made in the support substrate layer, under the first upper conductive surface of the microwave component.

[0166] The signal from port 1 is injected into the absorption zone 77 via the power supply element 79. It therefore passes through a transition between air and the substrate material. It is observed that the field amplitude gradually decreases during wave propagation in the absorption zone until it is completely canceled out.

[0167] The embodiments described above can be combined in any technically possible combination.

[0168] Thanks to the characteristics described above, the microwave component of this disclosure is simple and allows integration of a load to absorb an electromagnetic wave from the waveguide while being compact and low cost.

Claims

Demands

1. Microwave component (40), said component comprising: - at least one waveguide (42) comprising a propagation zone (48) of an electromagnetic wave, said propagation zone extending along a propagation axis; - a support substrate (44) of dielectric material adapted to ensure the mechanical rigidity of said component; - said support substrate comprising a first layer made of dielectric material having a first upper electrically conductive surface (44.1) and a first lower electrically conductive surface (44.2) covering respectively an upper face and a lower face of said support substrate; - at least one absorption zone (47) extending in the support substrate to guide the propagation of electromagnetic waves from said waveguide in the substrate in order to absorb the energy of the waves or to attenuate the energy of the waves, said absorption zone being delimited by the first upper electrically conductive surface (44.1), the first lower electrically conductive surface (44.2) and two spaced lateral boundaries (46) suitable for preventing the passage of an electromagnetic wave; - a feed element (49.1, 49.2) positioned at the entrance of said absorption zone (47) and configured to take at least a portion of the electromagnetic wave from said propagation zone (48) of said at least one waveguide and to inject it into said absorption zone (47).

2. Component according to claim 1, wherein said lateral boundaries of the absorption zone are formed by a plurality of metallized through holes (46, 56, 66, 86, 96) extending through the support substrate (44, 54, 64) to electrically connect the first upper electrically conductive surface and the first lower electrically conductive surface.

3. Component according to claim 2, wherein the plurality of plated through holes (46, 56, 66, 86, 96) defines a pattern having the shape of a meander.

4. Component according to claim 2, wherein the plurality of plated through holes (46, 56, 66, 86, 96) defines a pattern having the shape of a ring.

5. Component according to any one of claims 1 to 4, wherein the first layer made of dielectric material (44) has a thickness of between 0.2 mm and 10 mm, preferably between 0.5 mm and 6 mm.

6. A component according to any one of claims 1 to 5, wherein said at least one waveguide comprises a second layer of dielectric material (41, 51) having a second electrically conductive upper surface (41.1, 51.1) and a second electrically conductive lower surface (41.2, 51.2), said second electrically conductive lower surface (41.2, 51.2) being in electrical contact with said first electrically conductive upper surface (44.1, 54.1) of said support substrate, the propagation zone (48, 58) being defined in said second layer of dielectric material (41, 51) and bounded by the second electrically conductive upper surface (41.1, 51.1), the second electrically conductive lower surface (41.2, 51.2), and by a plurality of through-holes plated through-holes (43, 53) extending through said second layer of material dielectric.

7. Component according to claim 6, wherein said power element comprises a first slot (49.1, 59.1) made in the second lower conductive surface (41.2, 51.2) and a second slot (49.2, 59.1) made in the first upper conductive surface (44.1, 54.1), the two slots being aligned and arranged opposite the entrance of the absorption zone.

8. Component according to claim 7, wherein the power element comprises a set of metallized steps made in the support substrate, at the interface between the support substrate (54) and the first lower conductive surface (54.2).

9. A component according to any one of claims 1 to 5, wherein said at least one waveguide comprises a second layer of dielectric material (61) having a second electrically conductive upper surface (61.1) and a second electrically conductive lower surface (61.2), said second electrically conductive lower surface (61.2) being in electrical contact with said first electrically conductive upper surface (64.1) of said support substrate, said propagation zone (68) comprises an internal cavity (63) made in the support substrate, the side walls (68.1, 68.2) and the lower wall (68.3) of said cavity being metallized, the propagation zone being delimited by the second lower electrically conductive surface (61.2) and the metallized walls of the cavity (68.1, 68.2, 68.3).

10. Component according to claim 9, wherein the feed element comprises a hollow area (79) made in the support substrate (74), said hollow area being formed from an extension of one end of the internal cavity (73) of the waveguide (72).

11. Component according to claim 10, wherein the hollow area comprises a first end forming an interface with the end of the cavity and a second end in the form of a tip (79) penetrated into the absorption area (77) of the substrate.

12. Component according to claim 11, wherein the end of the cavity located at the interface with the first end of the hollow zone comprises a set of metallized steps (78) to achieve impedance matching between the cavity and the absorption zone.

13. Component according to claim 9, wherein said feed element comprises at least one slot (69, 89, 99) made in one of the walls of the internal cavity (83, 93) of the waveguide.

Images