Heart-shaped directional diagram implementation circuit and method
Through the combination of a multi-stage distribution network and a CNC phase shifter, the problem of insufficient reliability and accuracy in the implementation of the central pattern diagram of the prior art is solved, and a cardiac pattern with low loss, high reliability and high precision is realized, which is suitable for navigation systems.
Patent Information
- Application Number
- CN202411606897.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-12
- Publication Date
- 2025-03-21
AI Technical Summary
In the prior art, the reliability of the modulation device is not high, the accuracy and stability are average, and it cannot meet the requirements of high-precision positioning. At the same time, the design of the center omnidirectional antenna is not conducive to the integration of the mast, and the influence of the lightning rod leads to the waveform distortion of the cardiac direction diagram, affecting navigation performance.
A multi-stage distribution network is used to realize the cardiac pattern, including a six-input output power distribution network, a nine-input output amplitude phase distribution network, a nine-input output amplitude distribution network, and a three-input three-input amplitude phase distribution network. Through the CNC phase shifter periodically, the cardiac pattern is rotated, forming 27 radio frequency signals with different amplitude phases, and output to a uniform ring array antenna.
It realizes a cardiac pattern with low loss, high reliability, and stable amplitude consistency. It is suitable for navigation systems, avoids the influence of lightning rods, and does not need to occupy the high point position. It has the characteristics of high precision and calibration.
Smart Images
Figure CN119674538A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of array antennas, and in particular to a circuit and method for realizing a cardioid directional pattern. Background Art
[0002] TACAN is the abbreviation of tactical air navigation, which is an aerial short-range tactical radio polar coordinate navigation system, and is currently widely used by air forces of various countries. The TACAN function requires a nine-petal heart-shaped pattern, which can be understood in principle as the superposition of a 15Hz heart-shaped pattern and a 135Hz nine-petal pattern.
[0003] Generally, a heart-shaped pattern can be formed by superimposing an omnidirectional antenna with a modulator. The signal emitted by the coordinate center antenna unit is omnidirectional, and the corresponding pattern is circular. After the signal passes through the modulator, the pattern of the signal changes from circular to heart-shaped. When the modulator rotates around the center antenna at a speed of 15 circles per minute, the corresponding pattern also changes periodically, thus generating a 15Hz envelope amplitude modulation. The reliability of the modulators used in current technical means is not high, and the accuracy and stability are average, which can no longer meet the requirements of high-precision positioning. At the same time, the omnidirectional antenna at the center of the circle can only be placed at the highest point of the mast, which is not conducive to the integration of the mast. In addition, due to the influence of the lightning rod at the highest point, the waveform of the heart-shaped pattern is distorted, affecting the navigation performance.
[0004] Currently, there is no public report on a cardioid directional pattern multi-stage distribution network with low loss, high integration, high reliability, and high amplitude and phase consistency. Summary of the invention
[0005] In response to the above-mentioned problems, the present invention provides a circuit and method for realizing a cardioid radiation pattern. The RF input signal is distributed and synthesized through a digitally controlled phase shifter and various levels of distribution networks, and finally 27 RF signals with different amplitudes and phases are formed, which are output to a circular array antenna to realize a cardioid radiation pattern.
[0006] In order to solve the above technical problems, the present invention is achieved through the following technical solutions:
[0007] A cardioid directional pattern realization circuit comprises a one-input six-output power distribution network, two one-input nine-output amplitude and phase distribution networks, a one-input nine-output amplitude distribution network, nine three-input three-output amplitude and phase distribution networks and two digitally controlled phase shifters, wherein the input of the one-input six-output power distribution network is a radio frequency signal, three output ports are respectively connected to the one-input nine-output amplitude distribution network and the two digitally controlled phase shifters, and the other three output ports are connected to matching loads, the output of each digitally controlled phase shifter is connected to a one-input nine-output amplitude and phase distribution network, the input end of each three-input three-output amplitude and phase distribution network is respectively connected to two one-input nine-output amplitude and phase distribution networks and one output end of the one-input nine-output amplitude distribution network, and the output ends are all connected to antenna units.
[0008] Furthermore, the one-input six-output power distribution network includes a first coupler and three one-divided-to-two power dividers. The input signal is energy distributed through the first coupler. The through-port output of the first coupler serves as the output port of the one-input six-output power distribution network, and is connected to the input end of the one-input nine-output amplitude distribution network. The isolation port of the first coupler is connected to a matching load, and the coupling port output of the first coupler is connected to the input of a one-divided-to-two power divider. The output of the one-divided-to-two power divider is respectively connected to the input of another two one-divided-to-two power dividers to obtain four output ports, of which two output ports are respectively connected to two digitally controlled phase shifters, and the other two output ports are connected to matching loads.
[0009] Furthermore, the output power of the through port of the first coupler accounts for 96%, and the output power of the four output ports of the one-to-two power splitter accounts for 1% each.
[0010] Furthermore, the one-input nine-output amplitude-phase distribution network includes four unequal power dividers and four equal power dividers, the output of the digitally controlled phase shifter is connected to the first unequal power divider, the output of the first unequal power divider is respectively connected to the input ends of the second unequal power divider and the first equal power divider, an output port of the second unequal power divider is connected to the input port of the second equal power divider, and the other output port serves as the first output port, two outputs of the second equal power divider serve as the second output port and the third output port, two output ends of the first equal power divider are respectively connected to the third unequal power divider and the fourth unequal power divider, an output port of the third unequal power divider is connected to the input port of the third equal power divider, and the other output port serves as the fourth output port, two outputs of the third equal power divider serve as the fifth output port and the sixth output port, one output port of the fourth unequal power divider is connected to the input port of the fourth equal power divider, and the other output port serves as the seventh output port, and two outputs of the fourth equal power divider serve as the eighth output port and the ninth output port.
[0011] Furthermore, the power ratio of the output ports connected to the first unequal power divider, the second unequal power divider and the first equal power divider is 1:2, the signal amplitudes output by the nine output ports are equal, and the output phase difference of adjacent output ports is 13.33°.
[0012] Furthermore, the structure of the one-input nine-output amplitude distribution network is the same as the structure of the one-input nine-output amplitude and phase distribution network, and the nine outputs of the one-input nine-output amplitude distribution network have equal amplitudes and the same phases.
[0013] Furthermore, the three-input and three-output amplitude and phase distribution network includes a first coupler, a second coupler and a third coupler, the input port and the isolation port of the first coupler are used to connect the input signal, and its through port is connected to the through port of the second coupler, the coupling port of the first coupler is connected to the isolation port of the third coupler, the through port and the coupling port of the second coupler serve as the first output end and the second output end respectively, and its isolation port is connected to the through port of the third coupler, the input port of the third coupler is used to connect the input signal, and the coupling port serves as the third output end.
[0014] Furthermore, if the input signal is input through the input port of the first coupler, the output amplitudes of the first output terminal, the second output terminal and the third output terminal are equal, and the phases decrease by 120°; if the input signal is input through the isolation port of the first coupler, the output amplitudes of the first output terminal, the second output terminal and the third output terminal are equal, and the phases increase by 120°; if the input signal is input through the input port of the third coupler, the output amplitudes of the first output terminal, the second output terminal and the third output terminal are equal, and the phases are the same.
[0015] A cardioid directivity pattern realization method is provided. The SNP files of each distribution network simulation in the cardioid directivity pattern realization circuit are cascaded to obtain the amplitude and phase files of 27 ports, and then the cardioid directivity pattern is obtained through simulation.
[0016] A computer storage medium stores an executable program, and the executable program is executed by a processor to implement the steps of the method for realizing a cardioid-based directional pattern.
[0017] Compared with the prior art methods, the present invention has the following beneficial effects:
[0018] ① The present invention adopts a multi-level distribution network to realize a cardioid pattern, which has the characteristics of low loss, high reliability, and stable amplitude and phase consistency, and can be widely used in navigation systems;
[0019] ② The present invention adopts a multi-level distribution network to realize a heart-shaped directional diagram, which is conducive to the integrated design with the mast platform, will not be blocked by the lightning rod, and does not need to occupy the highest point position;
[0020] ③ The present invention adopts a cascaded digitally controlled phase shifter method, and the heart-shaped radiation pattern is periodically rotated by periodically changing the phase shifter, which has the characteristics of high precision and calibrability. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 FIG. 1 is a diagram of a one-input and six-output power distribution network in a specific implementation manner.
[0022] Figure 2 1 is a diagram of an amplitude-phase distribution network with one input and nine outputs in a specific implementation manner.
[0023] Figure 3 FIG. 1 is a diagram of a one-input and nine-output amplitude distribution network in a specific implementation manner.
[0024] Figure 4 It is a three-input and three-output amplitude and phase distribution network diagram in a specific implementation method.
[0025] Figure 5 It is a multi-level distribution network topology diagram in a specific implementation manner.
[0026] Figure 6 It is a cardioid directional diagram in a specific implementation manner. DETAILED DESCRIPTION
[0027] The present invention will be further described below by way of embodiments in conjunction with the accompanying drawings.
[0028] Combination Figure 1-Figure 5A circuit for realizing a cardioid radiation pattern, comprising a one-input six-output power distribution network A1, a one-input nine-output amplitude-phase distribution network B1-B2, a one-input nine-output amplitude-phase distribution network C1, a three-input three-output amplitude-phase distribution network D1-D9, and a digitally controlled phase shifter P1-P2; a radio frequency signal is input, and the signal is distributed and synthesized through the distribution networks at various levels to finally form the required 27-channel amplitude-phase, which is output to a uniform circular array antenna to realize a cardioid radiation pattern, wherein the one-input six-output power distribution network A1, A1_1 is an input port, A1_2, A1_3, and A1_4 are output ports, and the remaining ports A1_5 to A1_7 are connected to matching loads and do not participate in the next level of cascading; the first one-input nine-output amplitude-phase distribution network B1, B1_1 is an input port, B1_2-B1_10 are output ports, wherein B1_1 and A1_3 are connected to the matching loads and do not participate in the next level of cascading; the first one-input nine-output amplitude-phase distribution network B1, B1_1 is an input port, B1_2-B1_10 are output ports, wherein B1_1 and A1_3 are connected to the matching loads and do not participate in the next level of cascading. connected; the second one-input nine-output amplitude-phase distribution network B2, B2_1 is the input port, B2_2~B2_10 are output ports, wherein B2_1 is connected to A1_4; the one-input nine-output amplitude distribution network C1, C1_1 is the input port, C1_2~C1_10 are output ports, wherein C1_1 is connected to A1_2; the digitally controlled phase shifter P1 is between A1_3 and B1_1, and P2 is between A1_4 and B2_1; the three-input three-output amplitude-phase distribution network D1~D9 shown, taking D1 as an example, D1_1, D1_2, D1_3 are input ports, D1_3, D1_5, D1_6 are output ports, wherein D1_1 is connected to B1_2, wherein D1_2 is connected to C1_2, wherein D1_3 is connected to B2_10, and D1_4, D1_5, D1_6 are connected to the antenna unit.
[0029] Reference Figure 1 , one input six output power distribution network A1, A1_1 is the input port, A1_2, A1_3, A1_4 are output ports. The input signal is distributed through the coupler A11. The through port A11_2 of the coupler A11 corresponds to the output port A1_2 of the distribution network. The isolation port of the coupler A11 is the output port A1_7, which is connected to the matching load. The coupling port A11_3 of the coupler is connected to the input end of a one-to-two power divider A12. The output end of the one-to-two power divider A12 is respectively connected to another one-to-two power divider A12, and the output ports A1_3, A1_4, A1_5, and A1_6 are obtained. In actual use, the power of the input port A1_1 is 1W, the power of the output port A1_2 accounts for 96%, and the power of the output ports A1_3 and A1_4 accounts for 1% each. The remaining ports A1_5 to A1_7 are connected to matching loads and do not participate in the next level of cascading.
[0030] Reference Figure 2, the first one-input and nine-output amplitude and phase distribution network B1, B1_1 is the input port, and B1_2, B1_3, B1_4, B1_5, B1_6, B1_7, B1_8, B1_9, and B1_10 are output ports. The input signal is distributed in power through the first unequal power divider B11, the power of port B11_2 is half of the power of port B11_3, and is redistributed by ports B11_2 and B11_3, respectively, through transmission lines of unequal lengths to the second unequal power divider B12 and the input ports B12_1 and B11_3 of the first equal power divider. One output of the second unequal power divider B12 is used as the output port B1_2, and the other output port is connected to the second equal power divider to obtain output ports B1_3 and B1_4. The two outputs of the first equal power divider are respectively connected to the third unequal power divider B13 and the fourth unequal power divider B14. Like the second unequal power divider B12, one output is connected to the equal power divider to obtain output ports B1_5~B1_10. The output amplitudes of output ports B1_2~B1_10 are equal, and the phase difference between adjacent output ports is 13.33°.
[0031] Reference Figure 3 , similar to the first one-input nine-output amplitude and phase distribution network B1, one-input nine-output amplitude distribution network C1, C1_1 is the input port, C1_2~C1_10 are the output ports. The input signal passes through four unequal power dividers C11~C14 and four equal power dividers C15~C18, and finally the output signals at the output ports C1_2~C1_10 have equal amplitudes and the same phases.
[0032] Reference Figure 4, a three-input three-output amplitude-phase distribution network D1, D1_1, D1_2, D1_3 are input ports, and D1_4, D1_5, D1_6 are output ports. The distribution network is composed of a first coupler D11, a second coupler D12, and a third coupler D13. The through port D11_2 of the first coupler D11 is connected to the input port D12_1 of the second coupler D12, the coupling port D11_4 of the first coupler D11 is connected to the isolation port D13_3 of the third coupler D13, the isolation port D12_3 of the second coupler D12 is connected to the through port D13_2 of the third coupler D13, the input port D11_1 of the first coupler D11, the isolation port D11_3, and the input port D13_1 of the third coupler D13 are used as signal The input ports D1_1, D1_2, and D1_3, the through port D12_2 of the second coupler D12, the coupling port D11_4, and the coupling port of the third coupler D13 serve as the output ports D1_4, D1_5, and D1_6; if the input signal is input from D1_1, the output amplitudes at the output ports D1_4 to D1_6 are equal, and the phases decrease by 120°; if the input signal is input from D1_2, the output amplitudes at the output ports D1_4 to D1_6 are equal, and the phases increase by 120°; if the input signal is input from D1_3, the output amplitudes at the output ports D1_4 to D1_6 are equal, and the phases are the same.
[0033] The one-input nine-output amplitude-phase distribution network B1 and B2 have the same structure, and the three-input three-output amplitude-phase distribution network D1 to D9 have the same structure. The input and output ports of each level of distribution network correspond one to one, and the amplitude and phase required for excitation are formed through distribution and synthesis.
[0034] The following is a further description of the technical effects of the embodiments of the present invention in combination with simulation experiments:
[0035] 1. Simulation conditions and contents
[0036] A cardioid pattern realization method is to use electromagnetic simulation software to perform full-wave simulation on the cardioid pattern realization circuit in this embodiment, cascade the SNP files of each distribution network simulation, obtain the final 27-port amplitude and phase files, and perform theoretical pattern calculation. The pattern result is a cardioid, such as Figure 6 ,The experimental results show that the directional pattern has the ability of 15Hz envelope amplitude modulation.
[0037] The experiment provides a computer storage medium, which stores an executable program. The executable program is executed by a processor to implement the steps of the method for implementing the cardioid pattern.
[0038] In summary, a cardioid pattern realization circuit proposed by the present invention is composed of a one-input six-output power distribution network, a one-input nine-output amplitude-phase distribution network, a one-input nine-output amplitude-phase distribution network, a one-input nine-output amplitude distribution network, a three-input three-output amplitude-phase distribution network, and a digitally controlled phase shifter. The RF signal is input, and the signal is distributed and synthesized through the distribution networks at various levels to finally form the required 27-channel amplitude phase, which is output to the uniform circular array antenna to realize the cardioid pattern. At the same time, the cardioid pattern can be rotated through the periodic change of the digitally controlled phase shifter, and has the ability of 15Hz envelope amplitude modulation, and has the characteristics of low loss, high integration, high reliability, and high amplitude-phase consistency. Therefore, the present invention has certain application value in the field of high-precision navigation.
[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. A circuit for realizing a cardioid pattern, characterized in that: It includes a one-input six-output power distribution network, two one-input nine-output amplitude and phase distribution networks, one-input nine-output amplitude distribution network, nine three-input three-output amplitude and phase distribution networks and two digitally controlled phase shifters. The input of the one-input six-output power distribution network is a radio frequency signal, three output ports are respectively connected to the one-input nine-output amplitude distribution network and the two digitally controlled phase shifters, and the other three output ports are connected to matching loads. The output of each digitally controlled phase shifter is connected to a one-input nine-output amplitude and phase distribution network, and the input end of each three-input three-output amplitude and phase distribution network is respectively connected to two one-input nine-output amplitude and phase distribution networks and one output end of the one-input nine-output amplitude distribution network, and the output ends are all connected to antenna units.
2. A cardioid pattern realization circuit according to claim 1, characterized in that: The one-input six-output power distribution network includes a coupler and three one-to-two power dividers. The input signal is energy-distributed through the coupler. The through-port output of the coupler serves as the output port of the one-input six-output power distribution network and is connected to the input end of the one-input nine-output amplitude distribution network. The isolation port of the coupler is connected to a matching load. The coupling port output of the coupler is connected to the input of a one-to-two power divider. The output of the one-to-two power divider is respectively connected to the inputs of the other two one-to-two power dividers to obtain four output ports, of which two output ports are respectively connected to two digitally controlled phase shifters, and the other two output ports are connected to matching loads.
3. A cardioid pattern realization circuit according to claim 2, characterized in that: The output power of the through port of the coupler accounts for 96%, and the output power of the four output ports of the one-to-two power splitter accounts for 1% each.
4. A cardioid pattern realization circuit according to claim 1, characterized in that: The one-input nine-output amplitude-phase distribution network includes four unequal power dividers and four equal power dividers, the output of the digitally controlled phase shifter is connected to the first unequal power divider, the output of the first unequal power divider is respectively connected to the input ends of the second unequal power divider and the first equal power divider, an output port of the second unequal power divider is connected to the input port of the second equal power divider, and the other output port serves as the first output port, the two outputs of the second equal power divider serve as the second output port and the third output port, the two output ends of the first equal power divider are respectively connected to the third unequal power divider and the fourth unequal power divider, an output port of the third unequal power divider is connected to the input port of the third equal power divider, and the other output port serves as the fourth output port, the two outputs of the third equal power divider serve as the fifth output port and the sixth output port, an output port of the fourth unequal power divider is connected to the input port of the fourth equal power divider, and the other output port serves as the seventh output port, and the two outputs of the fourth equal power divider serve as the eighth output port and the ninth output port.
5. A cardioid pattern realization circuit according to claim 4, characterized in that: The power ratio of the output ports connected to the first unequal power divider, the second unequal power divider and the first equal power divider is 1:2, the signal amplitudes output by the nine output ports are equal, and the output phase difference of adjacent output ports is 13.33°.
6. A cardioid pattern realization circuit according to claim 4, characterized in that: The structure of the one-input nine-output amplitude distribution network is the same as the structure of the one-input nine-output amplitude and phase distribution network. The nine outputs of the one-input nine-output amplitude distribution network have equal amplitudes and the same phases.
7. A cardioid pattern realization circuit according to claim 1, characterized in that: The three-input and three-output amplitude and phase distribution network includes a first coupler, a second coupler and a third coupler. The input port and the isolation port of the first coupler are used to connect the input signal, and its through port is connected to the through port of the second coupler. The coupling port of the first coupler is connected to the isolation port of the third coupler. The through port and the coupling port of the second coupler serve as the first output end and the second output end respectively, and its isolation port is connected to the through port of the third coupler. The input port of the third coupler is used to connect the input signal, and the coupling port serves as the third output end.
8. A cardioid pattern realization circuit according to claim 7, characterized in that: If the input signal is input through the input port of the first coupler, the output amplitudes of the first output terminal, the second output terminal and the third output terminal are equal, and the phases decrease by 120°; if the input signal is input through the isolation port of the first coupler, the output amplitudes of the first output terminal, the second output terminal and the third output terminal are equal, and the phases increase by 120°; if the input signal is input through the input port of the third coupler, the output amplitudes of the first output terminal, the second output terminal and the third output terminal are equal, and the phases are the same.
9. A method for realizing a cardioid pattern, characterized in that: The SNP files of the distribution network simulations in the cardioid directional pattern realization circuit described in any one of claims 1 to 8 are cascaded to obtain the amplitude and phase files of 27 ports, and then the cardioid directional pattern is obtained through simulation.
10. A computer storage medium, characterized in that: The computer storage medium stores an executable program, and the executable program is executed by a processor to implement the steps of the method for realizing a cardioid pattern according to claim 9.