Array antenna protection system and method based on energy selection phase shifter

Abstract

The invention discloses an array antenna protection system and method based on energy selection phase shifters. The system comprises an array antenna, a power divider and a plurality of energy selection phase shifters, the input end of each energy selection phase shifter is connected with the antenna unit through an array element feed network, the output end of each energy selection phase shifter is connected with the power divider, and the output end of the power divider is used for outputting signals outwards and transmitting the signals to a rear-end transceiver; the selectable phase shifter is used for adjusting the phase of a signal of which the power level is greater than a threshold power level, and the power divider is responsible for integrating and cancelling the phase-shifted high-power signals; the energy selection phase shifters are divided into two types of energy selection phase shifters A and energy selection phase shifters B; and the energy selection phase shifters are alternately arranged to be an energy selection phase shifter A and an energy selection phase shifter B. According to the invention, a sensitive transceiver at the rear end of a signal with over-high power can be prevented, and the protection capability can be improved along with the enlargement of the array scale.

Description

Technical Field

[0001] The present invention relates to the field of strong electromagnetic protection, and in particular to an array antenna protection system and method based on an energy selective phase shifter. Background Art

[0002] Array antennas have both high gain and beam reconfiguration characteristics, and beam agility is achieved by controlling the array element feed phase. This feature of rapid beam scanning without physical movement makes it widely used in communication, tracking, telemetry, and control. Phased array antenna systems integrate a large number of highly sensitive precision electronic components, and the manufacturing cost is high. The high gain and high sensitivity of phased array antenna systems make them more vulnerable to damage when facing strong electromagnetic threats such as high-power microwaves. The economic losses caused by the damage of high-value phased array antenna systems under strong electromagnetic attacks are unbearable. Therefore, it is particularly important to implement strong electromagnetic protection measures for phased array antenna systems.

[0003] As a frequency-using device, the phased array antenna system cannot be protected by shielding, filtering or absorption. The current mainstream protection measures are to screen the signal amplitude (the power contained in the signal), including power limiters, energy selective surfaces, energy selective antennas and other energy selective protection measures. These measures can adaptively enter the high isolation protection mode when the power signal is injected to prevent harmful signals from entering the subsequent circuits. These methods mainly limit the amplitude of the signal. Although more semiconductor devices are used in larger-scale arrays, the protection level of the current methods will not increase as the array scale increases. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and to provide an array antenna protection system and method based on an energy selective phase shifter, in which the energy selective phase shifter is responsible for adjusting the phase of signals greater than a threshold power level, and the power divider is responsible for integrating and canceling these phase-shifted high-power signals to prevent excessively high-power signals from entering more sensitive transceiver equipment, and the protection capability can be improved as the array size increases.

[0005] The object of the present invention is achieved through the following technical solutions: an array antenna protection system based on energy selective phase shifters, comprising an array antenna, a power divider and a plurality of energy selective phase shifters;

[0006] The input end of each energy selective phase shifter is connected to the antenna unit through an array element feeding network, and the output end of each energy selective phase shifter is connected to the power distributor. The output end of the power distributor is used to output signals to the outside and transmit them to the back-end transceiver device;

[0007] The energy selective phase shifter is used to adjust the phase of the signal greater than the threshold power level, and the power divider is responsible for integrating and canceling these phase-shifted high-power signals;

[0008] The energy selective phase shifter is divided into two types: energy selective phase shifter A and energy selective phase shifter B; energy selective phase shifter A provides a lagging additional phase shift value in the protection mode, and energy selective phase shifter B provides an advanced phase shift value in the protection mode; and the energy selective phase shifter is alternately set to energy selective phase shifter A and energy selective phase shifter B.

[0009] The power distributor, i.e., the power divider, can also be used as a combiner, so that the output signals of each energy selective phase shifter can be synthesized and integrated and cancelled;

[0010] Preferably, the transceiver device is generally implemented using a transceiver chip, which is used to perform low-noise amplification, down-conversion and filtering on the signal output by the power divider and then convert it into a digital baseband signal through an ADC.

[0011] The array antenna comprises a plurality of antenna units, the number of the antenna units and the energy selective phase shifters are the same and correspond one to one, and each of the energy selective phase shifters is connected to the corresponding antenna unit via an array element feeding network.

[0012] The array element feeding network includes an array element antenna balun structure and an electronic phase shifter connected in sequence. The balun structure is responsible for balancing the array element feeding, and the electronic phase shifter is used to realize the beam electronic scanning capability of the array antenna.

[0013] The energy selective phase shifter A comprises a first capacitor C1, a second capacitor C2, a third capacitor C3, a first inductor L1, a second inductor L2 and a third inductor L3; the first end of the first capacitor C1 serves as the input end of the energy selective phase shifter A, the second end of the capacitor C1 is connected to the first end of the second capacitor C2 through the first inductor L1 and the second inductor L2 in sequence, and the second end of the second capacitor C2 serves as the output end of the energy selective phase shifter A; the first end of the third capacitor C3 is connected between the first inductor L1 and the second inductor L2, and the second end of the third capacitor C3 is grounded through the third inductor L3; two PIN diodes with opposite polarities are connected in parallel to both ends of the first capacitor C1, the second capacitor C2 and the third inductor C3.

[0014] The energy selective phase shifter B comprises a fourth capacitor L4, a fifth capacitor L5, a sixth capacitor L6, a seventh capacitor L7, a fourth capacitor C4 and a fifth capacitor C5;

[0015] The first end of the fourth inductor L4 serves as the input end of the energy selective phase shifter B, the second end of the fourth inductor L4 is connected to the first end of the fifth inductor L5 through the fourth capacitor C4 and the fifth capacitor C5 in sequence, and the second end of the fifth inductor L5 serves as the output end of the energy selective phase shifter B; the first end of the sixth inductor L6 is connected between the fourth capacitor C4 and the fifth capacitor C5, and the second end of the sixth inductor L6 is grounded through the seventh inductor L7; and two PIN diodes with opposite polarities are connected in parallel at both ends of the fourth inductor L4, the fifth inductor L5 and the seventh inductor L7.

[0016] An array antenna protection method based on an energy selective phase shifter comprises the following steps:

[0017] S1. In normal mode, the PIN diodes in the energy selective phase shifter A and the energy selective phase shifter B are not turned on, the PIN diodes are regarded as capacitors, and the energy selective phase shifter A and the energy selective phase shifter B remain transparent, providing no phase shift value and signal attenuation:

[0018] S2. When high-power microwaves irradiate the array antenna protection system, if the high-power RF signal coupled into the system from the array antenna makes the voltage across the PIN diode greater than the conduction threshold, the PIN diodes in the energy selective phase shifter A and the energy selective phase shifter B are adaptively activated to be turned on, so that the energy selective phase shifter A and the energy selective phase shifter B provide additional phase shift values, so that the array antenna protection system enters the adaptive protection mode.

[0019] In step S1, in the normal mode, the PIN diodes in the energy selective phase shifter A and the energy selective phase shifter B are not turned on, the PIN diodes are regarded as capacitors, and the energy selective phase shifter A and the energy selective phase shifter B remain transparent and do not provide any phase shift value and signal attenuation. The principle is as follows:

[0020] A1. In the energy selective phase shifter A, the first capacitor C1, two PIN diodes with opposite polarities connected in parallel at both ends of the first capacitor C1, and the first inductor L1 form a resonant structure, and no additional phase shift is provided on the transmission path; the second capacitor C2, two PIN diodes with opposite polarities connected in parallel at both ends of the second capacitor C2, and the second inductor L2 form a resonant structure, and no additional phase shift is provided on the transmission path; the third inductor L3 and the two PIN diodes with opposite polarities connected in parallel at both ends of the third inductor L3 block the grounding branch, making the branch invisible to the transmission path; therefore, the energy selective phase shifter A remains transparent and does not provide any phase shift value and signal attenuation;

[0021] A2. In the energy selective phase shifter B, the fourth inductor L4, the two PIN diodes with opposite polarities connected in parallel at both ends of the fourth inductor L4, and the fourth capacitor C4 form a resonant structure, and no additional phase shift is provided on the transmission path; the fifth inductor L5, the two PIN diodes with opposite polarities connected in parallel at both ends of the fifth inductor L5, and the fifth capacitor C5 form a resonance, and no additional phase shift is provided on the transmission path; the seventh inductor L7 and the two PIN diodes with opposite polarities connected in parallel at both ends of the seventh inductor L7 block the ground branch, making the branch invisible to the transmission path; therefore, the energy selective phase shifter B remains transparent and does not provide any phase shift value and signal attenuation.

[0022] In step S2, when the array antenna protection system is irradiated with high-power microwaves, if the high-power radio frequency signal coupled into the system from the array antenna makes the voltage across the PIN diode greater than the conduction threshold, the PIN diodes in the energy selective phase shifter A and the energy selective phase shifter B are adaptively activated to be turned on, so that the energy selective phase shifter A and the energy selective phase shifter B provide additional phase shift values, and the principle of the array antenna protection system entering the adaptive protection mode is as follows:

[0023] B1. When the PIN diode in the energy selective phase shifter A is turned on:

[0024] Two PIN diodes with opposite polarities connected in parallel at both ends of the first capacitor C1 short-circuit the first capacitor C1; two PIN diodes with opposite polarities connected in parallel at both ends of the second capacitor C2 short-circuit the second capacitor C2; the third inductor L3 and two PIN diodes with opposite polarities connected in parallel at both ends of the third inductor L3 short-circuit the third inductor;

[0025] At this time, the first inductor L1, the second inductor L2, and the third capacitor C3 form a T-type phase shift network, which plays a phase shift role;

[0026] B2. When the PIN diode of B in the energy selective phase shifter is turned on:

[0027] Two PIN diodes with opposite polarities connected in parallel at both ends of the fourth inductor L4 cause the fourth inductor L4 to be short-circuited;

[0028] Two PIN diodes with opposite polarities connected in parallel at both ends of the fifth inductor L5 cause the fifth inductor L5 to be short-circuited;

[0029] Two PIN diodes with opposite polarities connected in parallel at both ends of the seventh inductor L7 cause the seventh inductor L7 to be short-circuited;

[0030] The fourth capacitor C4, the fifth capacitor C5 and the sixth inductor L6 form a T-type phase shift network, which plays a phase shifting role;

[0031] B3. In order to make the duality between the energy selective phase shifter A and the energy selective phase shifter B, let

[0032]

[0033] Thus, the energy selective phase shifter A and the energy selective phase shifter B have opposite phase shift values ​​in the protection mode;

[0034] B4. Since the energy selective phase shifter A and the energy selective phase shifter B are set alternately, when the signal passing through the energy selective phase shifter A and the signal passing through the energy selective phase shifter B enter the power divider for synthesis, the high-power signal that has been phase-shifted will be integrated and canceled, thereby preventing excessively high-power signals from entering the later-end transceiver equipment.

[0035] The beneficial effects of the present invention are as follows: the present invention uses a selectable phase shifter to adjust the phase of a signal greater than a threshold power level, and a power divider to integrate and cancel these phase-shifted high-power signals, thereby preventing excessively high-power signals from entering more sensitive transceiver equipment, and the protection capability can be improved as the array size increases. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0037] Figure 2 Schematic diagram of the equivalent circuit of the energy selective phase shifter A;

[0038] Figure 3 Schematic diagram of the equivalent circuit of the energy selective phase shifter B;

[0039] Figure 4 An exploded view of a prototype in the embodiment;

[0040] Figure 5 is a schematic diagram of a feeding circuit in an embodiment;

[0041] Figure 6 : is a full-wave simulation result diagram of the voltage standing wave ratio of the antenna subarray in the normal mode in the embodiment;

[0042] Figure 7 This is a full-wave simulation result diagram of the gain pattern that can be achieved by the antenna subarray in the normal mode in the embodiment;

[0043] Figure 8 This is a full-wave simulation result diagram of the gain pattern that can be achieved by the antenna subarray in the protection mode in the embodiment;

[0044] Fig. 9 The full-wave simulation results of the gain pattern that can be achieved by the full array of antennas in the embodiment in the normal mode (a) and the protection mode (b);

[0045] Fig.10 The diagram is a graph showing the measured results of the beam electronic scanning capability of the full antenna array in the embodiment in normal mode. DETAILED DESCRIPTION

[0046] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings, but the protection scope of the present invention is not limited to the following.

[0047] like Figure 1 As shown, an array antenna protection system based on energy selective phase shifters includes an array antenna, a power divider, a transceiver chip and a plurality of energy selective phase shifters;

[0048] Figures 2-3 The equivalent circuit diagram of the energy selective phase shifter is given. The energy selective phase shifter can be divided into two types, A and B, according to the phase shift value provided in the protection mode. The energy selective phase shifter A provides a lagging additional phase shift value in the protection mode, and the energy selective phase shifter B provides an advanced phase shift value in the protection mode.

[0049] The energy selective phase shifter A comprises a first capacitor C1, a second capacitor C2, a third capacitor C3, a first inductor L1, a second inductor L2 and a third inductor L3; the first end of the first capacitor C1 serves as the input end of the energy selective phase shifter A, the second end of the capacitor C1 is connected to the first end of the second capacitor C2 through the first inductor L1 and the second inductor L2 in sequence, and the second end of the second capacitor C2 serves as the output end of the energy selective phase shifter A; the first end of the third capacitor C3 is connected between the first inductor L1 and the second inductor L2, and the second end of the third capacitor C3 is grounded through the third inductor L3; two PIN diodes with opposite polarities are connected in parallel to both ends of the first capacitor C1, the second capacitor C2 and the third inductor C3.

[0050] The energy selective phase shifter B comprises a fourth capacitor L4, a fifth capacitor L5, a sixth capacitor L6, a seventh capacitor L7, a fourth capacitor C4 and a fifth capacitor C5;

[0051] The first end of the fourth inductor L4 serves as the input end of the energy selective phase shifter B, the second end of the fourth inductor L4 is connected to the first end of the fifth inductor L5 through the fourth capacitor C4 and the fifth capacitor C5 in sequence, and the second end of the fifth inductor L5 serves as the output end of the energy selective phase shifter B; the first end of the sixth inductor L6 is connected between the fourth capacitor C4 and the fifth capacitor C5, and the second end of the sixth inductor L6 is grounded through the seventh inductor L7; and two PIN diodes with opposite polarities are connected in parallel at both ends of the fourth inductor L4, the fifth inductor L5 and the seventh inductor L7.

[0052] For energy selective phase shifter A, in protection mode, the PIN diode is turned on, short-circuiting C1, C2, and L3. L1, L2, and C3 play a phase shifting role. Energy selective phase shifter A is symmetrical in structure.

[0053]

[0054] Where x is the normalized impedance, b is the normalized admittance, and Z0 is the characteristic impedance of the system. After derivation, the phase shift value (radians) provided by the energy selective phase shifter A in the protection mode is

[0055]

[0056] In addition, considering that the phase shifter A needs to match the system impedance Z0, there is a constraint condition

[0057]

[0058] Given the protection mode required phase shift value and system impedance, a set of L1, L2, and C3 can be uniquely determined by equations (2) and (3).

[0059] In normal mode, the PIN diode is regarded as a capacitor. The PIN diode, C1 and L1 form a resonant structure to ensure that no additional phase shift is provided on the transmission path. Due to the symmetry of the structure, the PIN diode, C2 and L2 also form a resonant structure. L3 and the PIN diode block the ground branch, making the ground branch invisible to the transmission path.

[0060] For energy selective phase shifter B, in protection mode, the PIN diode is turned on, short-circuiting L4, L5, and L7. C4, C5, and L6 play a phase shifting role. Energy selective phase shifter B is symmetrical in structure.

[0061]

[0062] Where x' is the normalized impedance, b' is the normalized admittance, and Z0 is the characteristic impedance of the system. After derivation, the phase shift value (radians) provided by the energy selective phase shifter A in the protection mode is

[0063]

[0064] Similarly, there are matching constraints, namely

[0065]

[0066] When the protection mode required phase shift value and system impedance are given, a set of C4, C5, and L6 can be uniquely determined by equations (7) and (8).

[0067] In normal mode, the PIN diode is regarded as a capacitor. The PIN diode, L4 and C4 form a resonant structure to ensure that no additional phase shift is provided on the transmission path. Due to the symmetry of the structure, the PIN diode, L5 and C5 also form a resonant structure. For the same PIN diode, the value of L3 is equal to that of L7.

[0068] There is a duality between the selectable phase shifter A and the selectable phase shifter B. After the design of the selectable phase shifter A is completed, let

[0069]

[0070] A selectable phase shifter B with opposite phase shift values ​​in the protection mode is immediately available.

[0071] The energy selective phase shifter has two working states, normal mode and protection mode. In normal mode, the PIN diode is not turned on, forming a resonant structure with the LC element, so that the energy selective phase shifter remains transparent and does not provide any phase shift value and signal attenuation. In protection mode, the PIN short-circuits some peripheral components, allowing the T-type phase shift network to be visible and provide additional phase shift value. The switching process between the two modes is adaptive, does not require any bias circuit and control circuit, and has sufficient response speed to ensure that protection is implemented before the power signal damages the subsequent circuit.

[0072] The selective phase shifter can be implemented in a variety of forms, including but not limited to surface mount technology, printed circuit board technology, hybrid integrated substrate technology and H-cub technology.

[0073] The feed network includes the possible array element antenna balun structure and electronic phase shifter. The balun is responsible for balancing the array element feed, and the electronic phase shifter is used to achieve the beam scanning capability of the array antenna. The optional phase shifter is responsible for adjusting the phase of the signal greater than the threshold power level, and the power divider is responsible for integrating and canceling these phase-shifted high-power signals. Prevent excessively high-power signals from entering sensitive devices such as transceiver chips.

[0074] The array antenna equipped with energy selective phase shifters is endowed with the ability of selective beamforming. The beam of the array antenna will adaptively diverge under the irradiation of high-power microwaves, thereby reducing the total gain of the entire array antenna;

[0075] Energy selective phase shifters are the key to achieving energy selective beamforming. Usually, the total gain of an array antenna is equal to the array element antenna multiplied by the array factor:

[0076] G total (φ,θ)=G e (φ,θ)·AF(φ,θ) (8)

[0077] Where φ is the azimuth angle and θ is the elevation angle. For a two-dimensional uniform planar array, its array factor can be expressed as:

[0078]

[0079] M is the number of array elements in the x direction, N is the number of array elements in the y direction, A k is the complex voltage of the kth antenna element, (x k ,y k ) is the spatial coordinate of the kth array element antenna. The complex voltage can be further written in the form of modulus and phase

[0080]

[0081] Array element feeding phase α k In normal mode, the electronic phase shifter controls the k With φ k Keep the feed structure consistent across all array elements to achieve (φ k ,θ k ) direction is the array antenna beam pointing direction. In the protection mode, the array element feeding phase α k It is in a chaotic state to achieve an array factor without obvious directionality.

[0082] Specifically, for large-scale arrays, the random phase method should be used to implement the protection mode. For those array elements that need to lag the phase, the selectable phase shifter A is used, and for those that need to use the advanced phase, the selectable phase shifter B is used. For small-scale arrays and sub-array structures, the chessboard phase distribution helps to further improve the protection level, which requires that the phase difference between adjacent array elements is maintained at 180°. A feasible way is to use the following phase distribution form

[0083]

[0084] The above formula gives the distribution of the additional phase values ​​provided by the selective phase shifter in the protection mode of the 4×4 array. For those array element phases less than 0, the selective phase shifter A is used, and for those array element phases greater than 0, the selective phase shifter B is used.

[0085] The extra phase provided by the phase shifter in the protection mode will cause AF(φ,θ) to no longer maintain the converged beam and high gain in the normal mode, but to form a divergent beam and low gain array factor to achieve the protection effect. This scheme directly regulates the array factor. When the array scale is expanded, the newly added array elements will also participate in the cancellation instead of increasing the array factor. The final effect is that the protection level of this protection method increases with the increase of the array.

[0086] An array antenna protection method based on an energy selective phase shifter comprises the following steps:

[0087] S1. In normal mode, the PIN diodes in the energy selective phase shifter A and the energy selective phase shifter B are not turned on, the PIN diodes are regarded as capacitors, and the energy selective phase shifter A and the energy selective phase shifter B remain transparent, providing no phase shift value and signal attenuation:

[0088] S2. When high-power microwaves irradiate the array antenna protection system, if the high-power RF signal coupled into the system from the array antenna makes the voltage across the PIN diode greater than the conduction threshold, the PIN diodes in the energy selective phase shifter A and the energy selective phase shifter B are adaptively activated to be turned on, so that the energy selective phase shifter A and the energy selective phase shifter B provide additional phase shift values, so that the array antenna protection system enters the adaptive protection mode.

[0089] In step S1, in the normal mode, the PIN diodes in the energy selective phase shifter A and the energy selective phase shifter B are not turned on, the PIN diodes are regarded as capacitors, and the energy selective phase shifter A and the energy selective phase shifter B remain transparent and do not provide any phase shift value and signal attenuation. The principle is as follows:

[0090] A1. In the energy selective phase shifter A, the first capacitor C1, two PIN diodes with opposite polarities connected in parallel at both ends of the first capacitor C1, and the first inductor L1 form a resonant structure, and no additional phase shift is provided on the transmission path; the second capacitor C2, two PIN diodes with opposite polarities connected in parallel at both ends of the second capacitor C2, and the second inductor L2 form a resonant structure, and no additional phase shift is provided on the transmission path; the third inductor L3 and the two PIN diodes with opposite polarities connected in parallel at both ends of the third inductor L3 block the grounding branch, making the branch invisible to the transmission path; therefore, the energy selective phase shifter A remains transparent and does not provide any phase shift value and signal attenuation;

[0091] A2. In the energy selective phase shifter B, the fourth inductor L4, the two PIN diodes with opposite polarities connected in parallel at both ends of the fourth inductor L4, and the fourth capacitor C4 form a resonant structure, and no additional phase shift is provided on the transmission path; the fifth inductor L5, the two PIN diodes with opposite polarities connected in parallel at both ends of the fifth inductor L5, and the fifth capacitor C5 form a resonance, and no additional phase shift is provided on the transmission path; the seventh inductor L7 and the two PIN diodes with opposite polarities connected in parallel at both ends of the seventh inductor L7 block the ground branch, making the branch invisible to the transmission path; therefore, the energy selective phase shifter B remains transparent and does not provide any phase shift value and signal attenuation.

[0092] In step S2, when the array antenna protection system is irradiated with high-power microwaves, if the high-power radio frequency signal coupled into the system from the array antenna makes the voltage across the PIN diode greater than the conduction threshold, the PIN diodes in the energy selective phase shifter A and the energy selective phase shifter B are adaptively activated to be turned on, so that the energy selective phase shifter A and the energy selective phase shifter B provide additional phase shift values, and the principle of the array antenna protection system entering the adaptive protection mode is as follows:

[0093] B1. When the PIN diode in the energy selective phase shifter A is turned on:

[0094] Two PIN diodes with opposite polarities connected in parallel at both ends of the first capacitor C1 short-circuit the first capacitor C1; two PIN diodes with opposite polarities connected in parallel at both ends of the second capacitor C2 short-circuit the second capacitor C2; the third inductor L3 and two PIN diodes with opposite polarities connected in parallel at both ends of the third inductor L3 short-circuit the third inductor;

[0095] At this time, the first inductor L1, the second inductor L2, and the third capacitor C3 form a T-type phase shift network, which plays a phase shift role;

[0096] B2. When the PIN diode of B in the energy selective phase shifter is turned on:

[0097] Two PIN diodes with opposite polarities connected in parallel at both ends of the fourth inductor L4 cause the fourth inductor L4 to be short-circuited;

[0098] Two PIN diodes with opposite polarities connected in parallel at both ends of the fifth inductor L5 cause the fifth inductor L5 to be short-circuited;

[0099] Two PIN diodes with opposite polarities connected in parallel at both ends of the seventh inductor L7 cause the seventh inductor L7 to be short-circuited;

[0100] The fourth capacitor C4, the fifth capacitor C5 and the sixth inductor L6 form a T-type phase shift network, which plays a phase shifting role;

[0101] B3. In order to make the duality between the energy selective phase shifter A and the energy selective phase shifter B, let

[0102]

[0103] Thus, the energy selective phase shifter A and the energy selective phase shifter B have opposite phase shift values ​​in the protection mode;

[0104] B4. Since the energy selective phase shifter A and the energy selective phase shifter B are set alternately, when the signal passing through the energy selective phase shifter A and the signal passing through the energy selective phase shifter B enter the power divider for synthesis, the high-power signal that has been phase-shifted will be integrated and canceled, thereby preventing excessively high-power signals from entering the later-end transceiver equipment.

[0105] In the embodiment of the present application, in order to further illustrate the protection method, a principle prototype working at 2.3-2.4 GHz is designed. The exploded diagram of the principle prototype is as follows: Figure 4 As shown. The whole contains three metal layers and two dielectric layers. GND is basically covered by metal. There is 2.1mm thick FR-4 (relative dielectric constant is 4.3) between the antenna layer and GND, and 0.8mm thick F4B (relative dielectric constant is 2.2) between the feed layer and GND. The outline size of the multi-layer composite board is 350mm×350mm. This is a 4×4 two-dimensional planar array. The patch antenna array elements are evenly arranged, and their spacing in both dimensions is half the wavelength of the center frequency. The array elements are back-fed and connected to the feed circuit through metallized vias (these vias pass through two layers of substrate).

[0106] The details of the phase shifter section and power divider can be selected as follows Figure 5 As shown in the figure, the selective phase shifter is the first-level network closest to the antenna, which can be divided into two types, A and B, according to different positions. After the selective phase shift, the four array element antennas and the subsequent selective phase shifter are combined into one port through a two-stage Wilkinson power divider network. Such a 2×2 structure is called a subarray. The prototype contains a total of 4 such subarrays.

[0107] The selectable phase shifter A in this embodiment provides a -90° phase shift in the protection mode, while the selectable phase shifter B provides a +90° phase shift in the protection mode. Both phase shifters are implemented by surface mount components. The circuit schematic for the selectable phase shifter A is shown below. The two types of phase shifters A and B are distributed in the array in the form of a chessboard, and any type of selectable phase shifter is always adjacent to the other type of phase shifter in the x or y direction. These phase shifters are connected from the antenna layer to the GND layer through metallized vias through the ground in the. (These vias do not reach the Fr-4 layer).

[0108] The protection performance and beam scanning performance of the original machine were verified through full-wave simulation and actual processing. The full-wave simulation results show that the 2×2 sub-array has good matching in normal mode, and the voltage standing wave ratio VSWR is less than 2 in the full frequency band. Figure 6 shown.

[0109] The subarray has a focused beam in normal mode, providing a maximum gain of 8.8dBi in the main lobe direction, such as Figure 7 In the protection mode, the subarray beam diverges in a 4-leaf clover shape, providing a maximum protection level of 45dB. Figure 8 When considering a larger 4×4 array, the protection level is further improved to 52dB due to the participation of more array elements in the selective beamforming process, as shown below Fig. 9 As shown, the normal mode is Fig. 9 (a) and the protection mode are Fig. 9 This demonstrates the scalability of the protection level.

[0110] The actual test results show that the prototype can perform beam electronic scanning on the H plane. Although the original machine is not specially designed for scanning performance, it can still achieve a scanning angle of 15°. This proves the compatibility of the protection method with beam electronic scanning. The azimuth angle and normalized gain are as follows: Fig.10 As shown, the application of selective beamforming to the array antenna does not affect its beam electronic scanning capability.

Claims

1. An array antenna protection system based on energy selective phase shifter, characterized in that: It includes an array antenna, a power divider, and a plurality of energy selective phase shifters; The input end of each energy selective phase shifter is connected to the antenna unit through an array element feeding network, and the output end of each energy selective phase shifter is connected to the power distributor. The output end of the power distributor is used to output signals to the outside and transmit them to the back-end transceiver device; The energy selective phase shifter is used to adjust the phase of the signal greater than the threshold power level, and the power divider is responsible for integrating and canceling these phase-shifted high-power signals; The energy selective phase shifter is divided into two types: energy selective phase shifter A and energy selective phase shifter B; energy selective phase shifter A provides a lagging additional phase shift value in the protection mode, and energy selective phase shifter B provides an advanced phase shift value in the protection mode; and the energy selective phase shifter is alternately set to energy selective phase shifter A and energy selective phase shifter B.

2. The array antenna protection system based on energy selective phase shifter according to claim 1, characterized in that: The array antenna comprises a plurality of antenna units, the number of the antenna units and the energy selective phase shifters are the same and correspond one to one, and each of the energy selective phase shifters is connected to the corresponding antenna unit via an array element feeding network.

3. The array antenna protection system based on energy selective phase shifter according to claim 2, characterized in that: The array element feeding network includes an array element antenna balun structure and an electronic phase shifter connected in sequence. The balun structure is responsible for balancing the array element feeding, and the electronic phase shifter is used to realize the beam electronic scanning capability of the array antenna.

4. The array antenna protection system based on energy selective phase shifter according to claim 1, characterized in that: The energy selective phase shifter A comprises a first capacitor C1, a second capacitor C2, a third capacitor C3, a first inductor L1, a second inductor L2 and a third inductor L3; the first end of the first capacitor C1 serves as the input end of the energy selective phase shifter A, the second end of the capacitor C1 is connected to the first end of the second capacitor C2 through the first inductor L1 and the second inductor L2 in sequence, and the second end of the second capacitor C2 serves as the output end of the energy selective phase shifter A; the first end of the third capacitor C3 is connected between the first inductor L1 and the second inductor L2, and the second end of the third capacitor C3 is grounded through the third inductor L3; two PIN diodes with opposite polarities are connected in parallel to both ends of the first capacitor C1, the second capacitor C2 and the third inductor C3.

5. The array antenna protection system based on energy selective phase shifter according to claim 1, characterized in that: The energy selective phase shifter B includes a fourth inductor L4, a fifth inductor L5, a sixth inductor L6, a seventh inductor L7, a fourth capacitor C4 and a fifth capacitor C5; the first end of the fourth inductor L4 serves as the input end of the energy selective phase shifter B, the second end of the fourth inductor L4 is connected to the first end of the fifth inductor L5 through the fourth capacitor C4 and the fifth capacitor C5 in sequence, and the second end of the fifth inductor L5 serves as the output end of the energy selective phase shifter B; the first end of the sixth inductor L6 is connected between the fourth capacitor C4 and the fifth capacitor C5, and the second end of the sixth inductor L6 is grounded through the seventh inductor L7; and two PIN diodes with opposite polarities are connected in parallel at both ends of the fourth inductor L4, the fifth inductor L5 and the seventh inductor L7.

6. An array antenna protection method based on an energy selective phase shifter, based on the system according to any one of claims 1 to 5, characterized in that: include: S1. In normal mode, the PIN diodes in the energy selective phase shifter A and the energy selective phase shifter B are not turned on, the PIN diodes are regarded as capacitors, and the energy selective phase shifter A and the energy selective phase shifter B remain transparent, providing no phase shift value and signal attenuation: S2. When high-power microwaves irradiate the array antenna protection system, if the high-power RF signal coupled into the system from the array antenna makes the voltage across the PIN diode greater than the conduction threshold, the PIN diodes in the energy selective phase shifter A and the energy selective phase shifter B are adaptively activated to be turned on, so that the energy selective phase shifter A and the energy selective phase shifter B provide additional phase shift values, so that the array antenna protection system enters the adaptive protection mode.

7. The array antenna protection system based on energy selective phase shifter according to claim 6, characterized in that: In step S1, in the normal mode, the PIN diodes in the energy selective phase shifter A and the energy selective phase shifter B are not turned on, the PIN diodes are regarded as capacitors, and the energy selective phase shifter A and the energy selective phase shifter B remain transparent and do not provide any phase shift value and signal attenuation. The principle is as follows: A1. In the energy selective phase shifter A, the first capacitor C1, two PIN diodes with opposite polarities connected in parallel at both ends of the first capacitor C1, and the first inductor L1 form a resonant structure, and no additional phase shift is provided on the transmission path; the second capacitor C2, two PIN diodes with opposite polarities connected in parallel at both ends of the second capacitor C2, and the second inductor L2 form a resonant structure, and no additional phase shift is provided on the transmission path; the third inductor L3 and the two PIN diodes with opposite polarities connected in parallel at both ends of the third inductor L3 block the grounding branch, making the branch invisible to the transmission path; therefore, the energy selective phase shifter A remains transparent and does not provide any phase shift value and signal attenuation; A2. In the energy selective phase shifter B, the fourth inductor L4, the two PIN diodes with opposite polarities connected in parallel at both ends of the fourth inductor L4, and the fourth capacitor C4 form a resonant structure, and no additional phase shift is provided on the transmission path; the fifth inductor L5, the two PIN diodes with opposite polarities connected in parallel at both ends of the fifth inductor L5, and the fifth capacitor C5 form a resonance, and no additional phase shift is provided on the transmission path; the seventh inductor L7 and the two PIN diodes with opposite polarities connected in parallel at both ends of the seventh inductor L7 block the ground branch, making the branch invisible to the transmission path; therefore, the energy selective phase shifter B remains transparent and does not provide any phase shift value and signal attenuation.

8. The array antenna protection system based on energy selective phase shifter according to claim 6, characterized in that: In step S2, when the array antenna protection system is irradiated with high-power microwaves, if the high-power radio frequency signal coupled into the system from the array antenna makes the voltage across the PIN diode greater than the conduction threshold, the PIN diodes in the energy selective phase shifter A and the energy selective phase shifter B are adaptively activated to be turned on, so that the energy selective phase shifter A and the energy selective phase shifter B provide additional phase shift values, and the principle of the array antenna protection system entering the adaptive protection mode is as follows: B1. When the PIN diode in the energy selective phase shifter A is turned on: Two PIN diodes with opposite polarities connected in parallel at both ends of the first capacitor C1 short-circuit the first capacitor C1; two PIN diodes with opposite polarities connected in parallel at both ends of the second capacitor C2 short-circuit the second capacitor C2; the third inductor L3 and two PIN diodes with opposite polarities connected in parallel at both ends of the third inductor L3 short-circuit the third inductor; At this time, the first inductor L1, the second inductor L2, and the third capacitor C3 form a T-type phase shift network, which plays a phase shift role; B2. When the PIN diode of B in the energy selective phase shifter is turned on: Two PIN diodes with opposite polarities connected in parallel at both ends of the fourth inductor L4 cause the fourth inductor L4 to be short-circuited; Two PIN diodes with opposite polarities connected in parallel at both ends of the fifth inductor L5 cause the fifth inductor L5 to be short-circuited; Two PIN diodes with opposite polarities connected in parallel at both ends of the seventh inductor L7 cause the seventh inductor L7 to be short-circuited; The fourth capacitor C4, the fifth capacitor C5 and the sixth inductor L6 form a T-type phase shift network, which plays a phase shifting role; B3. In order to make the duality between the energy selective phase shifter A and the energy selective phase shifter B, let Thus, in the protection mode, the energy selective phase shifter A and the energy selective phase shifter B have opposite phase shift values; B4. Since the energy selective phase shifter A and the energy selective phase shifter B are set alternately, when the signal passing through the energy selective phase shifter A and the signal passing through the energy selective phase shifter B enter the power divider for synthesis, the high-power signal that has been phase-shifted will be integrated and canceled, thereby preventing excessively high-power signals from entering the later-end transceiver equipment.

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