Composite reconfigurable circularly polarized antenna based on broadband orthogonal phase-shift structure

Abstract

The present invention provides a composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure. The composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure comprises, from top to bottom, a first dielectric substrate, a first basal plane disposed on the upper surface of the first dielectric substrate, a ground layer disposed on the lower surface of the first dielectric substrate, the first basal plane being a ring formed by 2n metal patches intermittently surrounding the ring, where n is a positive integer greater than or equal to 2, adjacent metal patches being bridged with varactor diodes and lumped capacitors in sequence along the center of the ring outward, the metal patches being provided with DC bias points at their vertices extending outward from the center, and a second dielectric substrate, a broadband orthogonal feed network disposed on the lower surface of the second dielectric substrate. The present invention not only generates a circularly polarized radiation pattern, but also allows for continuous adjustment of the resonant frequency.

Description

Technical Field

[0001] The present invention relates to the field of antenna technology, and in particular to a composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure. Background Art

[0002] The design of circularly polarized antennas is of great significance in satellite communications and navigation. Satellite navigation systems typically operate in multiple frequency bands. Using multiple independent antennas to cover different operating bands can increase device size, making integrated RF aperture design crucial. Research on reconfigurable antennas provides an effective technical approach for antenna aperture integration. Therefore, reconfigurable circularly polarized antennas are an ideal choice for wireless RF systems, balancing system performance and RF aperture size.

[0003] It is known from related art that most reconfigurable circularly polarized antennas operate in discrete frequency bands, or even if continuous resonant frequency adjustment is achieved, the polarization mode within the operating frequency band cannot be changed. Summary of the Invention

[0004] The present invention provides a composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure, which is used to solve the defect in the prior art that the frequency reconfiguration and polarization reconfiguration of circularly polarized antennas are difficult to coexist. The circularly polarized antenna can not only generate a circularly polarized radiation pattern, but also continuously adjust the resonant frequency.

[0005] The present invention provides a composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure. The composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure comprises, from top to bottom: a first dielectric substrate, wherein a first base plane is provided on the upper surface of the first dielectric substrate, and a ground layer is provided on the lower surface of the first dielectric substrate. The first base plane is a ring formed by 2n metal patches in an intermittent manner, where n is a positive integer greater than or equal to 2. Adjacent metal patches are sequentially bridged with varactor diodes and lumped capacitors along the center of the ring outward. The metal patches are provided with DC bias points at their vertices along the center outward. A second dielectric substrate is also provided on the lower surface of the second dielectric substrate, and a broadband orthogonal feeding network is provided.

[0006] According to the present invention, a composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase shift structure is provided, characterized in that the broadband orthogonal feeding network includes a two-stage broadband Wilson power divider, a 90° phase shifter and a 180° phase shifter, wherein the 90° phase shifter and the 180° phase shifter share a branch line.

[0007] According to the present invention, a composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase shift structure is provided, characterized in that the broadband orthogonal feeding network includes three branch lines, wherein the 90° phase shifter includes a first branch line and a third branch line, and the 180° phase shifter includes the first branch line and the second branch line.

[0008] According to the present invention, a composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure is provided, characterized in that the first branch line, the second branch line, and the third branch line are respectively provided with a PIN diode.

[0009] According to the present invention, a composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure is provided, characterized in that the first base surface is a ring formed by four rectangular metal patches in an intermittent manner.

[0010] According to the present invention, a composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure is provided, characterized in that the first dielectric substrate and the second dielectric substrate are made of the same material.

[0011] According to the present invention, a composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure is provided, characterized in that the ground layer is a metal layer.

[0012] According to the present invention, a composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure is provided, characterized in that the ground layer is provided with a through hole.

[0013] The composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure provided by the present invention can achieve DC isolation and AC connectivity of each metal patch by bridging a varactor diode and a lumped capacitor between the independent metal patches of the circularly polarized antenna, thereby ensuring that the circularly polarized antenna can not only generate a circularly polarized radiation pattern but also continuously adjust the resonant frequency. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0015] Figure 1 This is one of the structural schematic diagrams of the composite reconfigurable circularly polarized antenna based on the broadband orthogonal phase-shift structure provided by the present invention;

[0016] Figure 2This is one of the structural schematic diagrams of the first base plane in the composite reconfigurable circularly polarized antenna based on the broadband orthogonal phase-shift structure provided by the present invention;

[0017] Figure 3 This is one of the structural schematic diagrams of the ground layer in the composite reconfigurable circularly polarized antenna based on the broadband orthogonal phase-shift structure provided by the present invention;

[0018] Figure 4 This is one of the structural diagrams of the broadband orthogonal feeding network in the composite reconfigurable circularly polarized antenna based on the broadband orthogonal phase-shift structure provided by the present invention;

[0019] Figure 5 This is a reflection coefficient result diagram of the composite reconfigurable circularly polarized antenna based on the broadband orthogonal phase-shift structure provided by the present invention;

[0020] Figure 6 This is a graph showing the axial ratio of the composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure provided by the present invention;

[0021] Figure 7a This is one of the left-hand circularly polarized typical frequency band working mode patterns of the composite reconfigurable circularly polarized antenna based on the broadband orthogonal phase-shift structure provided by the present invention;

[0022] Figure 7b This is the second left-hand circularly polarized typical frequency band working mode pattern of the composite reconfigurable circularly polarized antenna based on the broadband orthogonal phase-shift structure provided by the present invention;

[0023] Figure 7c This is the third left-hand circularly polarized typical frequency band working mode pattern of the composite reconfigurable circularly polarized antenna based on the broadband orthogonal phase-shift structure provided by the present invention;

[0024] Figure 7d This is one of the typical frequency band working mode patterns of the right-hand circular polarization of the composite reconfigurable circular polarization antenna based on the broadband orthogonal phase shift structure provided by the present invention;

[0025] Figure 7e This is the second right-hand circularly polarized typical frequency band working mode pattern of the composite reconfigurable circularly polarized antenna based on the broadband orthogonal phase-shift structure provided by the present invention;

[0026] Figure 7f This is the third typical frequency band working mode pattern of the right-hand circular polarization of the composite reconfigurable circular polarization antenna based on the broadband orthogonal phase shift structure provided by the present invention;

[0027] Figure 8 This is a diagram showing the output phase difference and amplitude difference of the broadband orthogonal feeding network provided by the present invention. DETAILED DESCRIPTION

[0028] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0029] Reconfigurable antennas offer an effective approach to antenna aperture synthesis. For wireless RF systems, reconfigurable circularly polarized antennas are an ideal choice for balancing system performance and RF aperture size. However, most reconfigurable circularly polarized antennas operate within discrete frequency bands, or even with continuous resonant frequency adjustment, cannot change the polarization within the operating frequency band.

[0030] The composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure provided by the present invention is based on 2n independent radiators (also known as metal patches). By loading varactor diodes on the cross resonant slots between the 2n radiators, it can not only ensure that the antenna produces a circularly polarized radiation pattern, but also ensure continuous adjustment of the resonant frequency.

[0031] The present invention will illustrate the structure of the composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure provided by the present invention in conjunction with the following embodiments.

[0032] Figure 1 This is one of the structural schematic diagrams of the composite reconfigurable circularly polarized antenna based on the broadband orthogonal phase-shift structure provided by the present invention.

[0033] In an exemplary embodiment of the present invention, Figure 1 As shown, the composite reconfigurable circularly polarized antenna 100 based on a broadband orthogonal phase-shift structure may include, from top to bottom, a first dielectric substrate 102 and a second dielectric substrate 104. Each component will be described below.

[0034] In one example, a first base surface 101 is provided on the upper surface of the first dielectric substrate 102, and a ground layer 103 is provided on the lower surface of the first dielectric substrate 102. It should be noted that the first base surface 101 is a ring formed by 2n metal patches in an intermittent manner, where n is a positive integer greater than or equal to 2. Adjacent metal patches are sequentially bridged with varactor diodes and lumped capacitors along the center of the ring outward, and DC bias points are provided at the vertices of the metal patches along the center outward. In application, each metal patch can serve as an independent radiator of the composite reconfigurable circularly polarized antenna 100 based on a broadband orthogonal phase-shift structure to achieve good isolation of the DC potential of the composite reconfigurable circularly polarized antenna 100 based on a broadband orthogonal phase-shift structure. Furthermore, by bridging the gaps between adjacent metal patches with varactor diodes and loading lumped capacitors outside the gaps between independent metal patches, AC communication is achieved.

[0035] In another example, a broadband orthogonal feed network 105 is provided on the lower surface of the second dielectric substrate 104. The broadband orthogonal feed network 105 can be a metal surface. This embodiment achieves good DC potential isolation without affecting the overall radiation performance of the composite reconfigurable circularly polarized antenna 100 based on the broadband orthogonal phase-shift structure.

[0036] In one example, the first dielectric substrate 102 and the second dielectric substrate 104 can be made of the same material. For example, the first dielectric substrate 102 and the second dielectric substrate 104 can be made of Rogers 5880™ material, which has a dielectric constant of 2.2 and a dielectric loss of 0.0009. In one example, the thickness of the first dielectric substrate 102 can be 1.575 mm, and the thickness of the second dielectric substrate 104 can be 0.787 mm.

[0037] The composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure provided by the present invention can achieve DC isolation and AC connectivity of each metal patch by bridging a varactor diode and a lumped capacitor between the independent metal patches of the antenna, thereby ensuring that the circularly polarized antenna can not only generate a circularly polarized radiation pattern but also continuously adjust the resonant frequency.

[0038] To further introduce the structure of a composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure, the present invention will illustrate the structures of the first base plane 101, the ground layer 103, and the broadband orthogonal feeding network 105 in the composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure in combination with the following embodiments.

[0039] Figure 2 This is one of the structural schematic diagrams of the first base plane in the composite reconfigurable circularly polarized antenna based on the broadband orthogonal phase-shift structure provided by the present invention.

[0040] In an exemplary embodiment of the present invention, Figure 2 As shown, the first basal surface 101 is a ring formed by 2n metal patches 1011 arranged in a discontinuous manner. In this embodiment, the first basal surface 101 is formed by four metal patches 1011 arranged in a discontinuous manner. It is understood that the metal patches 1011 arranged in a discontinuous manner to form the first basal surface 101 can form slots 1012 on the first basal surface 101. The presence of the slots 1012 ensures good DC potential isolation of the composite reconfigurable circularly polarized antenna 100 based on a broadband orthogonal phase-shift structure. Furthermore, by bridging the slots 1012 between adjacent metal patches 1011 with varactor diodes 1013 and adding lumped capacitors 1014 outside the slots 1012 between independent metal patches 1011, AC connectivity of the composite reconfigurable circularly polarized antenna 100 based on a broadband orthogonal phase-shift structure can be achieved. In this embodiment, four varactor diodes 1013 and eight lumped capacitors can be bridged.

[0041] In one example, a DC bias point 1015 can be provided at a vertex extending outward from the center of each metal patch 1011. For example, in this embodiment, four DC bias points 1015 can be provided, wherein two DC bias points 1015 located at diagonal positions can be used for ground connection, and the other two DC bias points 1015 located at diagonal positions can be used to provide DC bias for the varactor diode 1013. Furthermore, to ensure the normal operation of the composite reconfigurable circularly polarized antenna 100 based on the broadband orthogonal phase-shift structure, a feed point 1016 can be provided on the first base surface 101. In this embodiment, two feed points 1016 can be provided on the first base surface 101, and the composite reconfigurable circularly polarized antenna 100 based on the broadband orthogonal phase-shift structure is fed through the feed points 1016.

[0042] Figure 3 This is one of the structural schematic diagrams of the ground layer in the composite reconfigurable circularly polarized antenna based on the broadband orthogonal phase-shift structure provided by the present invention.

[0043] The following will be combined Figure 3 The structure of the ground layer in the composite reconfigurable circularly polarized antenna based on the broadband orthogonal phase-shift structure provided by the present invention is described.

[0044] In an exemplary embodiment of the present disclosure, Figure 3As shown, in one example, the ground layer 103 can be a metal layer, through which the ground connection of the composite reconfigurable circularly polarized antenna based on the broadband orthogonal phase-shift structure is achieved. The ground layer 103 can include a through hole. The ground connection or voltage access of the DC bias point 1015 in the first base surface 101 is achieved based on the through hole. In one example, the through hole can include a DC bias point through hole 1031, a short-circuit terminal grounding point through hole 1032, and a feed point through hole 1033. In this embodiment, the ground layer 103 is provided with four DC bias point through holes 1031. It can be understood that the DC bias point through holes 1031 correspond to the DC bias points 1015 on the first base surface 101.

[0045] In one example, two diagonally located DC bias points 1015 on the first substrate 101 can be metal-connected to the ground layer 103 via corresponding DC bias point vias 1031 to achieve grounding. The other two diagonally located DC bias points 1015 on the first substrate 101 can be metal-connected to the broadband orthogonal feed network 105 via corresponding DC bias point vias 1031, connected to DC bias points 1056. By applying a voltage to the DC bias points 1056 on the broadband orthogonal feed network 105, a bias voltage at the DC bias points 1015 is connected, thereby providing a DC bias, for example, a 0-20V voltage, to the varactor diode 1013.

[0046] Continuing with the above embodiment as an example, the ground layer 103 is further provided with a short-circuit terminal grounding point through-hole 1032. The phase-shifting branch in the broadband orthogonal feeding network 105 can be grounded through the short-circuit terminal grounding point through-hole 1032, thereby introducing a short-circuit stub line into the broadband orthogonal feeding network 105 to expand the operating bandwidth of the broadband orthogonal feeding network 105.

[0047] Figure 4 This is one of the structural schematic diagrams of the broadband orthogonal feeding network in the composite reconfigurable circularly polarized antenna based on the broadband orthogonal phase-shift structure provided by the present invention.

[0048] In an exemplary embodiment of the present disclosure, to achieve circular polarization operation, a composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase shift structure needs to be fed. In this embodiment, a broadband orthogonal feeding network 105 is provided on the lower surface of the second dielectric substrate 104. The broadband orthogonal feeding network 105 can be a metal surface and consists of a two-stage broadband Wilkinson power splitter, a 90° phase shifter, and a 180° phase shifter. The 90° and 180° phase shifters share a common stub line.

[0049] like Figure 4As shown, the broadband orthogonal feed network 105 includes three branch lines, namely a first branch line 1051, a second branch line 1052, and a third branch line 1053. The 90° phase shifter includes the first branch line 1051 and the third branch line 1053, and the 180° phase shifter includes the first branch line 1051 and the second branch line 1052. The introduction of the 90° phase shifter and the 180° phase shifter enables the first branch line 1051 and the third branch line 1053, and the second branch line 1052 and the third branch line 1053 to output orthogonal phases.

[0050] In another embodiment, to achieve broadband phase-shifting, a pin diode 1054 (only one pin diode is shown in the figure) can be provided on each of the first branch line 1051, the second branch line 1052, and the third branch line 1053 to introduce short-circuited and open-circuited branches into the phase-shifting branches, thereby expanding the operating bandwidth of the orthogonal phase-shifting network and compensating for the loss differences caused by the different lengths of the phase shifter branches. Furthermore, the branches of the introduced short-circuited and open-circuited terminals have better phase dispersion characteristics, and the slope of the phase change relative to the frequency can be controlled by adjusting the size of the short-circuited and open-circuited branches. The short-circuited terminals are connected to the ground layer 103 via through holes to achieve metal interconnection. At the same time, in order to achieve switching between the two output modes of +90° and -90°, PIN diodes 1054 are loaded on the first branch line 1051 and the second branch line 1052 to be switched in the broadband orthogonal feeding network 105. In order to maintain the amplitude and phase balance of the two branches of the phase shifter, two PIN diodes 1054 are simultaneously loaded on the non-switchable third branch line 1053 to control the amplitude difference between the two branches. In the working state, the third branch line 1053 is always in the on state.

[0051] After simulation verification, the four metal patches of the composite reconfigurable circularly polarized antenna based on the broadband orthogonal phase-shift structure proposed in the present invention realize DC isolation and AC connection, and the DC potential at both ends of the varactor diode is different. The composite reconfigurable circularly polarized antenna based on the broadband orthogonal phase-shift structure can achieve narrowband continuous adjustment in the 2-2.7GHz frequency band, and can switch between left-hand circular polarization and right-hand circular polarization working states. Its axial ratio is no more than 3dB, and the reflection coefficient at the resonant frequency is no more than -10dB. At the same time, the broadband orthogonal feeding network 105 with three branches can achieve a phase difference of 90°±5° between the two output ports and an amplitude difference of no more than 0.5dB within the range of 63% of the relative bandwidth.

[0052] In another embodiment, the broadband orthogonal feed network 105 may further include multiple short-circuit terminal grounding points 1055 and multiple DC bias points 1056. The short-circuit terminal grounding points 1055 correspond to the short-circuit terminal grounding point through-holes 1032 provided on the ground layer 103. The phase-shifting branches in the broadband orthogonal feed network 105 can be grounded via the short-circuit terminal grounding point through-holes 1032, thereby introducing short-circuit terminals into the broadband orthogonal feed network 105 to expand the operating bandwidth of the broadband orthogonal feed network 105. Some DC bias points 1056 in the broadband orthogonal feed network 105 correspond to the DC bias points 1015 on the first basal plane 101. By applying a bias voltage to the bias points 1056, a DC bias is applied to the varactor diodes 1013 on the first basal plane 101. Another portion of the DC bias points 1056 is used to apply a DC voltage to ensure the normal operation of the composite reconfigurable circularly polarized antenna based on the broadband orthogonal phase-shifting structure.

[0053] In order to further illustrate the composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure provided by the present invention, the following embodiments will be used for illustration.

[0054] Continuing with the example of the composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure with four metal patches described above, in this embodiment, the composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure includes four independent rectangular radiators (also known as metal patches), four DC bias points, eight lumped capacitors, and four varactor diodes.

[0055] In this embodiment, two DC bias points are connected to the ground plane through metal vias (also known as through-holes) for grounding. The other two DC bias points are metal-connected to the corresponding DC bias points on the broadband orthogonal feed network, and a 0-20V voltage is connected to the DC bias points.

[0056] Furthermore, the center operating frequency of the broadband orthogonal feed network's secondary broadband Wilkinson power divider is 2.3 GHz, and the isolation resistors have values ​​of 85 Ω and 250 Ω, respectively. The first branch (including the first branch line) of the broadband orthogonal feed network has a transmission line characteristic impedance of 50 Ω and a length of 2λg (λg is the wavelength corresponding to the center operating frequency). The length of the first branch is 3λg, the characteristic impedance of the short-circuit and open-circuit terminals is 63 Ω, and the characteristic impedance of the microstrip line connecting the pair of short-circuit and open-circuit terminals is 81 Ω. The length of the third branch (including the third branch line) is 2.5λg, the characteristic impedance of the short-circuit and open-circuit terminals is 126 Ω, and the characteristic impedance of the microstrip line connecting the pair of short-circuit and open-circuit terminals is 62 Ω.

[0057] Furthermore, a 2V voltage is connected to two DC bias points of the broadband orthogonal feeding network (for ease of explanation, respectively referred to as DC bias point 6 and DC bias point 8), a 0V voltage is connected to another DC bias point (referred to as DC bias point 5), and a 4V voltage is connected to another DC bias point (referred to as DC bias point 7). The first branch of the broadband orthogonal feeding network is connected to the third branch, and the antenna operates in a left-hand circular polarization state. In another example, a 2V voltage is connected to the DC bias point 5, a 4V voltage is connected to the DC bias point 7 and the DC bias point 8, and a 0V voltage is connected to the DC bias point 6. The second branch (including the second branch line) of the broadband orthogonal feeding network is connected to the third branch, and the antenna operates in a right-hand circular polarization state. Wherein, Figure 5 and Figure 8 This is a diagram of experimental results of the composite reconfigurable circularly polarized antenna based on the broadband orthogonal phase-shift structure of this embodiment.

[0058] Figure 5 This is a reflection coefficient result diagram of the composite reconfigurable circularly polarized antenna based on the broadband orthogonal phase-shift structure provided by the present invention.

[0059] like Figure 5 As shown in the figure, by changing the bias voltage of the composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure, the capacitance of the varactor diode changes. When the varactor diode capacitance is 0.3pF, 0.6pF, 0.9pF, 1.2pF, and 1.5pF, the center resonant frequencies in the left-hand circularly polarized state are 2.58GHz, 2.49GHz, 2.35GHz, 2.21GHz, and 2.05GHz, respectively. In the right-hand circularly polarized state, the center resonant frequencies are 2.08GHz, 2.20GHz, 2.35GHz, 2.45GHz, and 2.6GHz, respectively. As can be seen from the figure, in both polarization states, the center resonant frequency is within the range of 2-2.7GHz, and the reflection coefficient of the composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure is no higher than -10dB.

[0060] Figure 6 This is a graph showing the axial ratio results of the composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure provided by the present invention.

[0061] according to Figure 6 It can be seen that within the five typical frequency bands shown in the figure, the antenna axial ratio is less than 3dB in both left-hand circular polarization and right-hand circular polarization working states.

[0062] like Figures 7a to 7f As shown, Figures 7a to 7c These are the left-hand circular polarization radiation patterns at three typical frequencies: 2.58 GHz, 2.35 GHz, and 2.05 GHz. Figures 7d to 7fThe diagram shows the right-hand circularly polarized radiation patterns at three typical operating frequencies: 2.6 GHz, 2.35 GHz, and 2.08 GHz. As shown in the figure, the maximum radiation pattern and maximum gain direction of the circularly polarized radiation pattern remain the same within the 2-2.7 GHz range, but two different rotation directions can be generated. This shows that the composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure provided in this embodiment can switch between left-hand and right-hand circular polarization within the continuous frequency band of 2-2.7 GHz.

[0063] Figure 8 This is a diagram showing the output phase difference and amplitude difference of the broadband orthogonal feeding network provided by the present invention.

[0064] according to Figure 8 It can be seen that in the 1.6GHz-3.1GHz frequency band, in the left-hand circular polarization working mode, the absolute value of the amplitude difference between output port 1 and output port 2 is less than 0.25dB, and the phase difference is in the range of 85.1°-94.3°; in the right-hand circular polarization working mode, the amplitude difference between output port 1 and output port 2 is less than 0.5dB, and the phase difference is in the range of 85.5°-94.9°.

[0065] Based on the same inventive concept, the present invention also provides a method for applying a DC bias voltage to a planar patch antenna loaded with an even number of varactor diodes. Specifically, the present invention also provides a method for applying a bias voltage to the aforementioned composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure.

[0066] The present invention will illustrate the process of the bias voltage application method of the composite reconfigurable circularly polarized antenna based on the broadband orthogonal phase-shift structure in conjunction with the following embodiments.

[0067] In an exemplary embodiment of the present invention, a DC bias voltage can be provided to 2n varactor diodes, and an entire metal surface can be divided into 2n radiators (also known as metal patches) to ensure that the divided radiators are independent of each other. Wherein, n is a positive integer greater than or equal to 2, and the divided radiators are numbered consecutively in a clockwise direction. In order to ensure the integrity of the radiation current between the 2n radiators and not affect the overall radiation performance of the original antenna, a lumped capacitor is loaded outside the gap between the 2n independent radiators for AC connection. At this time, all radiators achieve DC isolation and AC connectivity. Furthermore, an equal number of DC bias points are loaded at the vertices of the 2n DC-isolated radiators, and the radiator numbered 2k-1 is grounded, and the radiator numbered 2k is connected to an equipotential DC bias voltage, where k = 1, 2, ..., n.

[0068] According to the above description, the composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure provided by the present invention can achieve DC isolation and AC connectivity of each metal patch by bridging a varactor diode and a lumped capacitor between the independent metal patches of the circularly polarized antenna, thereby ensuring that the circularly polarized antenna can not only generate a circularly polarized radiation pattern, but also continuously adjust the resonant frequency.

[0069] It should be further understood that, although operations are described in a particular order in the accompanying drawings in the embodiments of the present invention, this should not be construed as requiring that the operations be performed in the particular order shown or in a serial order, or that all of the operations shown be performed to obtain the desired results. In certain circumstances, multitasking and parallel processing may be advantageous.

[0070] Other embodiments of the present invention will readily occur to those skilled in the art after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the invention being indicated by the following claims.

[0071] It should be understood that the present invention is not limited to the exact construction described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure, characterized in that: The composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure includes, from top to bottom: A first dielectric substrate, wherein the upper surface of the first dielectric substrate is provided with a first base surface, and the lower surface of the first dielectric substrate is provided with a ground layer, wherein the first base surface is a ring formed by 2n metal patches in an intermittent manner, n is a positive integer greater than or equal to 2, and adjacent metal patches are sequentially bridged with varactor diodes and lumped capacitors along the center of the ring outward, and the metal patches are provided with DC bias points at the vertices along the center outward, and a second dielectric substrate, wherein the lower surface of the second dielectric substrate is provided with a broadband orthogonal feeding network, wherein by applying a DC bias point at the broadband orthogonal feeding network, A voltage is applied to achieve access to the bias voltage at the DC bias point, thereby providing a DC bias for the varactor diode, wherein the broadband orthogonal feeding network includes a two-stage broadband Wilson power divider, a 90° phase shifter, and a 180° phase shifter, wherein the 90° phase shifter and the 180° phase shifter share a branch line, and the broadband orthogonal feeding network includes three branch lines, wherein the 90° phase shifter includes a first branch line and a third branch line, and the 180° phase shifter includes the first branch line and the second branch line, and the first branch line, the second branch line, and the third branch line are respectively provided with a PIN diode.

2. The composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure according to claim 1, characterized in that: The first base surface is a ring shaped by four rectangular metal patches that are intermittently surrounded.

3. The composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure according to claim 1, characterized in that: The first dielectric substrate and the second dielectric substrate are made of the same material.

4. The composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure according to claim 1, characterized in that: The ground layer is a metal layer.

5. The composite reconfigurable circularly polarized antenna based on a broadband orthogonal phase-shift structure according to claim 4, characterized in that: The ground layer is provided with a through hole.

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