A full polarisation programmable antenna unit

Abstract

A full polarization programmable antenna unit comprises a digital amplitude and phase programmable matching network module and a horn type radiation antenna module; the digital amplitude and phase programmable matching network module comprises a T-type power divider, a 90-degree directional coupler, an FPGA control module and two 360-degree digital phase shifters; the amplitude adjustable through power divider, 360-degree phase shifter and 90-degree directional coupler are cascaded with each other, and programmable regulation and control are realized by the FPGA control module. The amplitude and phase modulation of two polarization components of the antenna unit can be realized through the digital amplitude and phase programmable matching network module. Specifically, the programmable matching network module for feeding is connected with the antenna radiator through a radio frequency coaxial line, which greatly improves the full polarization programmable capability. In a complex and changeable electromagnetic environment, polarization loss can be reduced and polarization interference capability can be improved through variable polarization, and the full polarization programmable antenna unit can also be applied to polarization imaging and other application scenarios in combination with related algorithms for polarization information recognition.

Description

Technical Field

[0001] This utility model belongs to the field of wireless communication technology, and mainly relates to a fully polarized programmable antenna unit. Background Technology

[0002] Antenna polarization is a crucial parameter describing the direction of the electric field radiated or received electromagnetic waves. The matching between antenna polarization and electromagnetic wave polarization directly affects the signal transmission quality of a communication system. Therefore, traditional passive antennas are often designed with polarization modes adapted to the characteristics of the application scenario. However, with the advent of the information age, traditional antenna designs with fixed transmitting or receiving polarizations are struggling to meet the increasingly complex and demanding electromagnetic operating environments. To adapt to changing application scenarios and achieve higher data transmission rates, polarization-adjustable antennas that can dynamically switch polarization states have gradually become one of the research hotspots in the antenna field.

[0003] Currently, polarimetric tunable antennas hold significant research value in applications such as wireless communication, radar ranging and imaging, and navigation countermeasures. In wireless communication, within the same frequency band, polarimetric tunable antennas can establish different polarization channels by dynamically adjusting the polarization, thereby achieving polarization reuse, improving spectrum utilization, and increasing the maximum signal transmission rate. In radar ranging, polarimetric tunable antennas can effectively suppress multipath fading caused by reflection and scattering by matching the receiver to the optimal polarization direction of the signal, improving signal reception quality. For radar imaging, the amplitude and phase information of the target echo in the polarization domain can reflect the shape, attitude, and motion of the target object to a certain extent, which is beneficial to improving imaging accuracy. In navigation countermeasures, in addition to the spatial, energy, and frequency domains, polarimetric tunable antennas can interfere with navigation equipment equipped with multi-element adaptive nulling antennas from a polarization domain perspective by changing different polarizations. The addition of polarization domain interference, in addition to traditional spatial and temporal domain interference methods, can further enhance the interference effect.

[0004] To meet the needs of these different scenarios, experts and scholars both domestically and internationally have conducted extensive research on polarization-reconfigurable antennas. Some methods achieve control of several polarization modes through mechanical adjustment. However, due to the difficulty in resolving mechanical errors and poor real-time performance caused by mechanical control, electrically tunable polarization antennas have gradually become a more mainstream research direction. Compared to mechanically tunable antennas, electrically tunable polarization antennas have significant advantages such as shorter polarization response time and more flexible circuit design. They utilize electrical switches to interconnect adjacent radiating patch elements, and control the switches to change the path of the surface current to radiate different polarization waves. These designs typically require a large number of PIN diodes to achieve more polarization state switching, which may lead to increased insertion loss and more complex DC bias feed networks, hindering further expansion of polarization tunability. Therefore, the limited range of electrically tunable polarization greatly restricts the widespread application of electrically tunable polarization antennas. Utility Model Content

[0005] To overcome the aforementioned shortcomings, this invention provides a fully polarized programmable antenna unit, including 0-180 degree linear polarization, left and right circular polarization, and left and right elliptical polarization with arbitrary axis ratios and tilt angles. While ensuring agile polarization response, it further expands the adjustable polarization range. Furthermore, FPGA-based digital control effectively realizes polarization programmability, providing a relatively complete hardware platform for the introduction of polarization control algorithms. Combined with the current application requirements for polarization control capabilities in radar, communication, and electronic countermeasures fields, this invention has considerable application prospects.

[0006] The technical solution adopted by this utility model to solve its technical problem is as follows:

[0007] A fully polarizable programmable antenna unit includes a digital amplitude and phase programmable matching network module and a horn-shaped radiating antenna module;

[0008] The digital amplitude-phase programmable matching network module includes: a T-type power divider, a 90-degree directional coupler, an FPGA control module, and two 360-degree digital phase shifters;

[0009] The input terminal of the T-type power divider is connected to the radio frequency coaxial line, one output terminal of the T-type power divider is connected to one input terminal of the 90-degree directional coupler, the other output terminal of the T-type power divider is connected to the input terminal of the first 360-degree digital phase shifter, and the output terminal of the first 360-degree digital phase shifter is connected to the other input terminal of the 90-degree directional coupler.

[0010] One output of the 90-degree directional coupler is connected to the second 360-degree digital phase shifter. The other output of the 90-degree directional coupler and the output of the second 360-degree digital phase shifter are the two outputs of the digital amplitude-phase programmable matching network, which are respectively connected to the two feed ports of the horn-type radiating antenna module through radio frequency coaxial adapters.

[0011] The 16-bit control pins of the FPGA control module are connected to the first 360-degree digital phase shifter and the second 360-degree digital phase shifter via DuPont lines, and the phase shift range of the 360-degree phase shifter is controlled by high and low levels.

[0012] The horn-shaped radiating antenna module adopts a narrowband horn antenna or a broadband double-ridge horn antenna.

[0013] The output of the amplitude-phase programmable matching network module is connected to the horn-shaped radiating antenna module via an RF coaxial adapter.

[0014] A fully polarized programmable antenna is formed by a periodic array arrangement of multiple fully polarized programmable antenna elements.

[0015] Due to the adoption of the technical solution described above, this utility model has the following advantages:

[0016] This invention provides a fully polarization-programmable antenna unit. The digital amplitude-phase programmable matching network, through the cascading of digital phase shifters and RF devices and FPGA control circuitry, can achieve full-range modulation of the amplitude and phase difference of two output signals simply by controlling the phase shifter's phase modulation. Compared to the traditional method of adjusting the amplitude ratio using active amplifiers and attenuators, this method can reduce the combined power loss by up to 3dB, which is a significant technical advantage for overall system performance, especially for reducing transmit power consumption. Secondly, in the current field of polarization-tunable antennas, this invention extends the polarization control range to agile control across the entire polarization range, greatly improving the polarization reconfigurability of existing antennas. Furthermore, the FPGA-based digital control effectively realizes polarization programmability, providing a relatively complete hardware platform for the introduction of polarization control algorithms. It can be flexibly applied to polarization imaging, polarization interference, and other application scenarios, meeting a wide range of application needs. Attached Figure Description

[0017] Figure 1 This is a unit architecture diagram of an antenna according to the present invention;

[0018] Figure 2 A schematic diagram of a digital amplitude-phase programmable matching network module;

[0019] Figure 3 This is a schematic diagram of a horn-shaped radiating antenna module;

[0020] Figure 4 The amplitude curves of S21 and S31 of the digital amplitude-phase programmable matching network module of this utility model at 1.5GHz;

[0021] Figure 5The phase difference curves of S21 and S31 at 1.5GHz for the digital amplitude-phase programmable matching network module of this utility model;

[0022] Figure 6 The reflection coefficient of the antenna element of this utility model;

[0023] Figure 7 This is a three-dimensional radiation pattern of the antenna element in an embodiment of the present invention;

[0024] Figure 8 Two-dimensional surface current diagram of antenna element when linear polarization is 90 degrees;

[0025] Figure 9 For left-hand circular polarization, the two-dimensional surface current diagram of the antenna element;

[0026] Figure 10 For right-hand circular polarization, the two-dimensional surface current diagram of the antenna element;

[0027] Figure 11 Two-dimensional surface current diagram of an antenna element with a left-handed elliptic polarization, an X-axis angle of 43 degrees and an axial ratio of 3;

[0028] Figure 12 The far-field two-dimensional radiation pattern of the E-plane element in the left-hand circularly polarized state;

[0029] Figure 13 The far-field two-dimensional radiation pattern of the H-plane element in the left-hand circularly polarized state;

[0030] Figure 14 The far-field two-dimensional radiation pattern of the cross-polarized E-plane unit under left-hand circular polarization;

[0031] Figure 15 This is a two-dimensional far-field radiation pattern of a cross-polarized H-plane element in a left-handed circularly polarized state. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0033] Reference Figure 1 and Figure 2A fully polarizable programmable antenna unit is disclosed. The antenna adopts a modular design, including a digital amplitude and phase programmable matching network module 101 and a horn-shaped radiating antenna module 102. The output terminal of the amplitude and phase programmable matching network module 101 is connected to the horn-shaped radiating antenna module 102 via an RF coaxial interface.

[0034] The input of the digital amplitude-phase programmable matching network module 101 is connected to the RF coaxial line. When the RF signal excites the digital amplitude-phase programmable matching network module 101, it enables eight-bit (256 selectable modes) digital control of the amplitude of the two RF output signals with arbitrary amplitude distribution ratios from 0:1 to 1:0, and eight-bit (256 selectable modes) digital control of the phase difference from 0 to 360 degrees. The two output ports of the digital amplitude-phase programmable matching network module are respectively connected to the radiation structure, exciting two mutually orthogonal polarization components, thereby achieving fully adjustable polarization with arbitrary linear polarization angles from 0 to 180 degrees, left-hand or right-hand circular polarization, and left-hand or right-hand elliptical polarization with arbitrary axis ratios and tilt angles.

[0035] The digital amplitude-phase programmable matching network module 101 includes: a T-type power divider 1015, a 90-degree directional coupler 1014, an FPGA control module 1013, and two 360-degree digital phase shifters 1012-1 and 1012-2. The power divider 1015, the 360-degree phase shifters 1012-1 and 1012-2, and the 90-degree directional coupler 1014 are cascaded together, and the FPGA control module 1013 enables programmable control.

[0036] In this embodiment, the input terminal of the T-type power divider 1015 is connected to an RF signal source, one output terminal of the T-type power divider 1015 is connected to one input terminal of the 90-degree directional coupler 1014, the other output terminal of the T-type power divider 1015 is connected to the input terminal of the first 360-degree digital phase shifter 1012-1, and the output terminal of the first 360-degree digital phase shifter 1012-1 is connected to the other input terminal of the 90-degree directional coupler 1014.

[0037] In this embodiment, the 90-degree directional coupler 1014 is used to superimpose two signal vectors with a phase difference, and outputs signals with the same phase and amplitude distribution ratio within the range of 0:1 to 1:0 at the two output terminals of the 90-degree directional coupler 1014. One output terminal of the 90-degree directional coupler 1014 is connected to the second 360-degree digital phase shifter 1012-2, and the other output terminal of the 90-degree directional coupler 1014 and the output terminal of the second 360-degree digital phase shifter 1012-2 are the two output terminals of the digital amplitude-phase programmable matching network 101, which are respectively connected to the two feed ports of the horn-type radiating antenna module 102 through RF coaxial adapters.

[0038] In this embodiment, the 16-bit control pins of the FPGA control module 1013 are connected to the first 360-degree digital phase shifter 1012-1 and the second 360-degree digital phase shifter 1012-2 via DuPont lines, respectively, and the phase shift range of the 360-degree phase shifter is controlled by high and low level signals. 00000000 to 11111111 correspond to 0 to 360 degrees, respectively, with a phase accuracy of 1.4 degrees.

[0039] In this embodiment, the 360-degree digital phase shifter (1012-1; 1012-2) is a cascade of an 8-bit digital phase shifter chip PE44820B-X and a compensation amplifier.

[0040] The horn-shaped radiating antenna module 102 is connected to the output of the digital amplitude-phase programmable matching network module 101. The horn-shaped radiating antenna module 102 is used to radiate the amplitude-phase modulated radio frequency signal in free space. Finally, through vector synthesis of polarization components, the antenna element can achieve full polarization adjustment of arbitrary linear polarization angle from 0 to 180 degrees, left-hand or right-hand circular polarization, and left-hand or right-hand elliptical polarization with arbitrary axis ratio.

[0041] In this embodiment, the digital amplitude-phase programmable matching network module 101 and the horn-type radiating antenna module 102 are connected via an RF coaxial adapter.

[0042] In this embodiment, the horn-shaped radiating antenna module 102 may be implemented in various forms, including but not limited to a narrowband dual-polarized horn antenna or a broadband dual-polarized horn antenna.

[0043] A fully polarized programmable antenna is formed by a periodic array arrangement of multiple fully polarized programmable antenna elements.

[0044] Reference Figure 4In the specific design process of the FPGA-based amplitude-phase programmable matching network module 101, in order to achieve simulation verification, the ideal performance indicators of the T-type power divider 1015, the 90-degree directional coupler 1014, the FPGA control module 1013, and the two 360-degree digital phase shifters 1012-1 and 1012-2 are written into the MATLAB program as input data. The MATLAB software is used to perform mathematical modeling to obtain the amplitude and phase data of the two output signals of the amplitude-phase programmable matching network, that is, the amplitude and phase difference characteristics of the network S21 and S31. In order to simplify the simulation calculation, considering that the cascading between each RF device is ideally matched and lossless, the amplitude and phase data of the two output signals of the amplitude-phase programmable matching network module 101 are obtained at the 1.5GHz frequency point. Specifically, as the first 360-degree digital phase shifter 1012-1 continues to adjust the phase, the horizontal axis changes from π / 2 to 3π / 2, and the amplitudes of S21 and S31 change accordingly. As can be seen from the vertical axis, |S21|:|S31| changes from 1:0 to 0:1, thus verifying the full amplitude adjustable performance of the digital amplitude and phase programmable matching network.

[0045] Reference Figure 5 The phase difference between S21 and S31 changes with the phase adjustment of the second 360-degree digital phase shifter 1012-2, and the phase difference can be adjusted from 0 to 2π, thereby verifying the full-phase adjustable performance of the digital amplitude-phase programmable matching network. According to electromagnetic theory, any electromagnetic wave in space can be synthesized from a pair of orthogonal linearly polarized waves with different amplitude ratios and phase differences. When the radiation structure is an orthogonal dual-polarized horn antenna 102, the amplitude-phase modulation performance of the digital amplitude-phase programmable matching network module 101 in this embodiment is sufficient to meet the feeding requirements of the fully polarized programmable antenna.

[0046] Reference Figure 6-15 The amplitude and phase data calculated by MATLAB were imported into the CST three-dimensional electromagnetic simulation software and used as the excitation characteristic parameters of the back-end RF excitation source of the dual-polarized horn antenna 102 for MATLAB-CST joint simulation.

[0047] Figure 6 To simulate the reflection coefficient of the fully polarized programmable antenna element, taking 90-degree linear polarization as an example, the simulation yields the amplitude of the antenna element's reflection coefficient. It can be observed that within the range of 1.4 to 2 GHz, S11 fluctuates between 0.07 and 0.17, which is between -15 dB and -23 dB. This indicates that the matching state is good.

[0048] Reference Figure 7 At this point, the radiation direction of the antenna element is perpendicular to the horn aperture plane, demonstrating the radiation pattern characteristics of this embodiment. (Refer to...) Figure 8-11The direction of surface current indicates the change in polarization state, verifying the adjustable polarization function of this embodiment. Taking left-handed circular polarization as an example, it can be seen that... Figure 12 , 13 The E-plane and H-plane two-dimensional radiation patterns are shown in the left-hand circularly polarized state. The main lobe gain reaches 14.3 dBi at 1.5 GHz, and both the sidelobe horizontal and main lobe gains are below -20 dB. Figure 14 and Figure 15 As can be seen, compared with the main polarization, the cross-polarization / main polarization is less than -11dB, and the polarization purity is sufficient to meet the antenna design requirements, successfully verifying the feasibility of the fully polarized programmable unit design method.

[0049] During the design process, the beam parameters, operating frequency, and polarization of the antenna elements are first analyzed. Based on the required frequency and polarization, a digital amplitude-phase programmable matching network module and a horn-type radiating antenna module are designed and integrated.

[0050] This invention discloses a fully polarized programmable antenna unit that can achieve amplitude and phase modulation of the two polarization components of the antenna unit through a digital amplitude and phase programmable matching network module. Specifically, the programmable matching network module used for power supply is connected to the antenna radiator through an RF coaxial cable, which greatly improves the fully polarized programmability. It can reduce polarization loss and improve polarization interference capability by changing polarization in complex and variable electromagnetic environments. It can also be combined with relevant algorithms for polarization information recognition and applied to polarization imaging and other application scenarios.

[0051] The parts not detailed above are existing technologies and therefore have not been described in detail.

Claims

1. A fully polarizable programmable antenna element, characterized in that: It includes a digital amplitude and phase programmable matching network module (101) and a horn-shaped radiating antenna module (102); The digital amplitude-phase programmable matching network module (101) includes: a T-type power divider (1015), a 90-degree directional coupler (1014), an FPGA control module (1013), a first two 360-degree digital phase shifters (1012-1), and a second two 360-degree digital phase shifters (1012-2). The input terminal of the T-type power divider (1015) is connected to an RF signal source. One output terminal of the T-type power divider (1015) is connected to one input terminal of a 90-degree directional coupler (1014). The other output terminal of the T-type power divider (1015) is connected to the input terminal of a first 360-degree digital phase shifter (1012-1). The output terminal of the first 360-degree digital phase shifter (1012-1) is connected to the other input terminal of the 90-degree directional coupler (1014). One output terminal of the 90-degree directional coupler (1014) is connected to the second 360-degree digital phase shifter (1012-2). The other output terminal of the 90-degree directional coupler (1014) and the output terminal of the second 360-degree digital phase shifter (1012-2) are the two output terminals of the digital amplitude-phase programmable matching network module (101), which are respectively connected to the two feed ports of the horn-type radiating antenna module (102) through radio frequency coaxial adapters. The 16-bit control pins of the FPGA control module (1013) are connected to the first 360-degree digital phase shifter (1012-1) and the second 360-degree digital phase shifter (1012-2) via DuPont lines, and the phase shift range of the first 360-degree digital phase shifter (1012-1) and the second 360-degree digital phase shifter (1012-2) is controlled by high and low level.

2. The fully polarizable programmable antenna element according to claim 1, characterized in that: The horn-shaped radiating antenna module (102) adopts a narrowband dual-polarized horn antenna or a broadband dual-polarized horn antenna.

3. The fully polarizable programmable antenna element according to claim 1, characterized in that: The output of the amplitude-phase programmable matching network module (101) is connected to the horn-shaped radiating antenna module (102) via an RF coaxial adapter.

4. A fully polarizable programmable antenna, characterized in that: It is formed by a periodic array arrangement of multiple fully polarized programmable antenna elements as described in claim 1, 2 or 3.

Images