A low-loss switch-select line phase shifter
By optimizing the switch configuration and introducing a low-loss switch-selection linear phase shifter with a switchable compensation network, the insertion loss and circuit complexity problems of traditional phase shifters in multi-phase shifting are solved, realizing a low-loss and highly integrated phase shifter design.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NORTHWEST INST OF NUCLEAR TECH
- Filing Date
- 2026-04-13
- Publication Date
- 2026-07-14
AI Technical Summary
Traditional switching requires cascading multiple single-pole double-throw switches to achieve multi-phase shifts using linear phase shifters, resulting in accumulated insertion losses, reduced power capacity, and increased circuit complexity, making it unsuitable for high-integration and low-loss applications.
A phase shifter consisting of two transmission lines of unequal length is used, combined with single-pole double-throw and single-pole single-throw switches. By selecting different delay lines and controlling the on/off state of the compensation network, the number of single-pole double-throw switches is reduced, thus achieving low-loss phase shifting.
It effectively reduces insertion loss and overall size, making it suitable for microwave transceiver components and possessing significant engineering application value.
Smart Images
Figure CN122394520A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of microwave engineering technology, and specifically relates to a low-loss switch selection linear phase shifter. Background Technology
[0002] Phase shifters are an important component of phased array radars. Phased array antenna elements all contain phase shifters and attenuators. By adjusting the phase shifters and attenuators, the antenna phase and attenuation can be controlled, enabling the synthesis of arbitrary beam directions. In modern phased array systems, the performance requirements for phase shifters are increasingly demanding. They not only need to possess wide bandwidth, low insertion loss, and high phase accuracy, but also minimize circuit size to meet the requirements of high-density integration.
[0003] Traditional switch-selective linear phase shifters typically employ a multi-stage single-pole double-throw (SPDT) switch structure, achieving discrete phase states by switching transmission lines of varying lengths. However, this structure requires cascading multiple SPDT switches to achieve multi-phase shifts, leading to accumulated insertion losses, reduced power capacity, increased circuit complexity and overall size, which is detrimental to applications requiring high integration and low loss.
[0004] The present invention proposes a low-loss switch selection linear phase shifter, which, by optimizing the switch configuration and introducing a switchable compensation network, can reduce the number of single-pole double-throw switches, effectively reduce insertion loss and reduce overall size, and has significant engineering application value. Summary of the Invention
[0005] The purpose of this invention is to provide a low-loss switch-selective linear phase shifter by using a phase shifter composed of two transmission line branches and a single-pole double-throw switch to select different delay lines to achieve phase delay. In one of the branches, the single-pole single-throw switch controls the on / off state of the compensation network to achieve phase delay and reduce the insertion loss of the phase shifter.
[0006] To achieve the above objectives, the technical solution provided by this invention is as follows:
[0007] A low-loss switch-selective linear phase shifter includes two phase-shifting branches composed of two transmission lines of unequal length. A single-pole double-throw switch is designed at the input or output end of the phase-shifting branch. The single-pole double-throw switch is used to select the two phase-shifting branches to achieve two different phase delays. At the input or output end of the second phase-shifting branch, a single-pole single-throw switch is designed to control the on / off state of the compensation network.
[0008] Length of Phase Shift Branch 1 for The length of the second phase-shifting branch for ,in, For positive integers, phase-shifting branch one and phase-shifting branch two For one-to-one correspondence, The wavelength corresponding to the center frequency. The phase constant corresponding to the center frequency. The phase difference between phase-shifting branch one and phase-shifting branch two.
[0009] The single-pole double-throw switch and single-pole single-throw switch can be any type of PIN switch, electromagnetic relay switch, MEMS switch, GaN HEMT switch, etc.
[0010] The single-pole double-throw switch can be designed at the input or output of the two branches of the phase-shifting branch.
[0011] The first scenario is: when the single-pole double-throw switch is at the input end, the single-pole single-throw switch is at the input end of phase-shifting branch two; the second scenario is: when the single-pole double-throw switch is at the output end, the single-pole single-throw switch is at the output end of phase-shifting branch two.
[0012] In the first scenario, the single-pole double-throw switch is at the input terminal, connecting the input terminal to phase-shifting branch one. When the single-pole double-throw switch is off from the input terminal to phase-shifting branch two, the single-pole double-throw switch is on, the compensation network is integrated into phase-shifting branch two, and phase-shifting branch two is effectively open at the output terminal. The output signal is phase-shifted compared to the input signal. This state is called state one; the single-pole double-throw switch is at the input terminal, the single-pole double-throw switch connects the input terminal and phase-shifting branch two, the single-pole double-throw switch disconnects the input terminal and phase-shifting branch one, the single-pole single-throw switch is closed, the compensation network is disconnected from phase-shifting branch two, phase-shifting branch one is effectively open at the output terminal, and the output signal is phase-shifted compared to the input signal. This state is called state two.
[0013] In the second scenario, the single-pole double-throw switch is at the output terminal, and its output terminal is connected to phase-shifting branch one. The output terminal of the single-pole double-throw switch is also disconnected from phase-shifting branch two. When the single-pole double-throw switch is connected, the compensation network is integrated into phase-shifting branch two, which is effectively open at its input terminal. The output signal is phase-shifted compared to the input signal. This state is called state three; the single-pole double-throw switch is at the output terminal, the output terminal of the single-pole double-throw switch is connected to phase-shifting branch two, the output terminal of the single-pole double-throw switch is disconnected from phase-shifting branch one, the single-pole single-throw switch is closed, the compensation network is disconnected from phase-shifting branch two, phase-shifting branch one is equivalently open-circuited at the input terminal, and the output signal is phase-shifted compared to the input signal. This state is called state four.
[0014] The compensation network can be a microstrip short-circuit stub, a microstrip open-circuit stub, a single-stub matching unit, a multi-stub matching unit, an RC circuit, an RLC circuit, etc., and its phase... .
[0015] Specifically, the phase difference is At that time, no compensation network is needed, among which, It is a positive integer.
[0016] By cascading M low-loss switch-selected linear phase shifters, an M-position low-loss switch-selected linear phase shifter can be obtained, which can achieve phase control through multiple switches.
[0017] The M-bit low-loss switch-select linear phase shifter comprises M cascaded low-loss switch-select linear phase shifters, that is, it can contain M... a The first scenario involves a low-loss switch selecting a linear phase shifter, M. b The second scenario involves a low-loss switch selection linear phase shifter, where M... a M b The integers are 0, 1, 2, ..., M, and M a +M b =M; M≥2.
[0018] The M-position low-loss switch-selector linear phase shifter has a phase shifting branch length Li1 of its i-th stage low-loss switch-selector linear phase shifter as follows: The length of phase-shifting branch two, Li2, is ,in, For positive integers, phase-shifting branch one and phase-shifting branch two For one-to-one correspondence, The wavelength corresponding to the center frequency. The phase constant corresponding to the center frequency. The i-th stage low-loss switch selects the phase difference between phase shifting branch one and phase shifting branch two of the linear phase shifter.
[0019] The M-position low-loss switch-selected linear phase shifter, if its i-th stage low-loss switch-selected linear phase shifter is in the first case, the single-pole double-throw switch is at the input end, the single-pole double-throw switch connects the input end and the first phase shifting branch, the single-pole double-throw switch disconnects the input end and the second phase shifting branch, the single-pole single-throw switch is on, the compensation network is connected to the second phase shifting branch, the second phase shifting branch is effectively open at the output end, and the output signal is phase-shifted compared to the input signal. State 1: The single-pole double-throw switch is at the input terminal, connecting the input terminal to phase-shifting branch 2. When the single-pole double-throw switch is off, it disconnects the input terminal from phase-shifting branch 1. The compensation network is disconnected from phase-shifting branch 2, and phase-shifting branch 1 is effectively open at the output terminal. The output signal is phase-shifted compared to the input signal. This is state two.
[0020] The M-position low-loss switch-selector linear phase shifter, if its i-th stage low-loss switch-selector linear phase shifter is the second case, has a single-pole double-throw switch at the output terminal, the output terminal of the single-pole double-throw switch connected to phase shift branch one, the output terminal of the single-pole double-throw switch disconnected from phase shift branch two, the single-pole single-throw switch connected, the compensation network integrated into phase shift branch two, and phase shift branch two is effectively open-circuited at the input terminal, resulting in a phase shift in the output signal compared to the input signal. State 3: The single-pole double-throw switch is at the output terminal. The output terminal of the single-pole double-throw switch is connected to phase-shifting branch 2, and the output terminal of the single-pole double-throw switch is disconnected from phase-shifting branch 1. The single-pole double-throw switch is closed, the compensation network is disconnected from phase-shifting branch 2, and phase-shifting branch 1 is effectively open at the input terminal. The output signal is phase-shifted compared to the input signal. This is state four.
[0021] The M-position low-loss switch-selection linear phase shifter, and the compensation network of its i-th stage low-loss switch-selection linear phase shifter, can be a microstrip short-circuit stub, a microstrip open-circuit stub, a single-stub matching unit, a multi-stub matching unit, an RC circuit, an RLC circuit, etc., and its phase... .
[0022] Compared with the prior art, the present invention has the following beneficial technical effects:
[0023] 1. This invention reduces the number of single-pole double-throw switches by optimizing switch configuration and introducing a switchable compensation network, thereby effectively reducing insertion loss and overall size.
[0024] 2. This invention is applicable to microwave transceiver components and other applications, and has significant engineering application value in fields such as phased array radar and wireless communication. Attached Figure Description
[0025] Figure 1 This is a schematic diagram of a single-pole double-throw switch with the phase shifter at the input end, according to an embodiment of a low-loss switch selection linear phase shifter of the present invention, wherein a) is state one and b) is state two;
[0026] Figure 2 This is a schematic diagram of a single-pole double-throw PIN switch circuit in an embodiment of the present invention;
[0027] Figure 3 This is a schematic diagram of a single-pole single-throw PIN switch circuit in an embodiment of the present invention;
[0028] Figure 4 The figure shows the S-parameter simulation results curves for the first case in the embodiments of the present invention, where a) transmission coefficient S21, b) reflection coefficient S11, c) transmission phase delay, and d) phase difference between state one and state two.
[0029] Figure 5This is a schematic diagram of the phase shifter at the output end of the single-pole double-throw switch in an embodiment of the present invention, where a) is state three and b) is state four;
[0030] Figure 6 The figure shows the S-parameter simulation results curves for the second scenario in this embodiment of the invention, where a) transmission coefficient S21, b) reflection coefficient S11, c) transmission phase delay, and d) phase difference between state three and state four.
[0031] Figure 7 This is a schematic diagram of a conventional switch-selection linear phase shifter in an embodiment of the present invention;
[0032] Figure 8 The figure shows the S-parameter simulation results of the embodiment of the present invention and the conventional switch-selection linear phase shifter, where a) transmission coefficient S21, b) reflection coefficient S11, c) transmission phase delay, and d) phase difference between the present invention and the conventional one.
[0033] Figure 9 This is a schematic diagram of a two-position low-loss switch selection linear phase shifter in an embodiment of the present invention;
[0034] Figure 10 The figure shows the S-parameter simulation results of the two-position low-loss switch selection linear phase shifter in this embodiment of the invention, where a) transmission coefficient S21, b) reflection coefficient S11, c) transmission phase delay, and d) phase difference between the three phase states and the reference branch.
[0035] Figure 11 This is a schematic diagram of the overall structure of the phase shifter with the single-pole double-throw switch at the input end in an embodiment of the present invention. Detailed Implementation
[0036] To make the objectives, advantages, and features of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Those skilled in the art should understand that these embodiments are merely used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.
[0037] like Figure 1 As shown, this embodiment provides a low-loss switch-selection linear phase shifter, including: a phase-shifting branch composed of two transmission lines of unequal length; a single-pole double-throw switch at the input end for selecting the two phase-shifting branches to achieve two unequal phase delays; and a single-pole single-throw switch connected in parallel at the input end of the second phase-shifting branch to control the on / off state of the compensation network.
[0038] Length of Phase Shift Branch 1 Its phase shift ; length of phase-shifting branch two Its phase shift ,in, The phase constant is the one corresponding to the center frequency, and the compensation network consists of short-circuit stubs.
[0039] like Figure 2 As shown, the single-pole double-throw PIN switch controls the on / off state of RF1 and RFCom, and the on / off state of RF2 and RFCom, respectively, through bias voltages V1 and V2. Figure 1 The input terminal is connected to a single-pole double-throw switch RFCom, phase shift branch one is connected to RF1, and phase shift branch two is connected to RF2.
[0040] like Figure 3 As shown, the single-pole single-throw PIN switch controls the conduction of RFin and RFout through the bias voltage V3. Figure 1 The second branch of the China Mobile phase is connected to RFin, and the compensation network is connected to RFout.
[0041] Bias voltage V1 is reverse biased, and the single-pole double-throw switch connects the input terminal to phase-shifting branch one; bias voltage V2 is forward biased, and the single-pole double-throw switch disconnects the input terminal from phase-shifting branch two; bias voltage V3 is forward biased, and the single-pole single-throw switch connects, the compensation network is connected to phase-shifting branch two, and phase-shifting branch two is effectively open-circuited at the output terminal, resulting in a phase shift in the output signal compared to the input signal. This is state one.
[0042] With bias voltage V1 reverse biased, the single-pole double-throw switch shuts off the input terminal and phase-shifting branch one; with bias voltage V2 forward biased, the single-pole double-throw switch connects the input terminal and phase-shifting branch two; with bias voltage V3 reverse biased, the single-pole single-throw switch closes, the compensation network disconnects from phase-shifting branch two, and phase-shifting branch one is effectively open at the output terminal, resulting in phase shifting of the output signal. This is state two.
[0043] like Figure 4 As shown, the S-parameter simulation results curves for the first case are presented. Figure 4 a) is the transmission coefficient S21 for state one and state two; Figure 4 b) represents the reflection coefficient S11 for states one and two. As can be seen from the figure, within the frequency band f0-1.5 to f0+1.5, where f0 is the center frequency, the phase shifter insertion loss is less than 0.57dB, and the return loss is greater than 11dB. Figure 4 c) represents the phase delay between state one and state two. Figure 4 d) represents the phase difference between the two. As can be seen from the figure, the phase of state one lags behind the phase of state two by 90°. By controlling the switch to select the phase shift branch, 0° and 90° phase shifts can be achieved.
[0044] like Figure 5As shown, the phase shifter in the second case of the single-pole double-throw switch at the output end of this embodiment includes a phase shifting branch composed of two transmission lines of unequal length; a single-pole double-throw switch is designed at the output end, which is used to select the two phase shifting branches to achieve two unequal phase delays; at the output end of the second phase shifting branch, a single-pole single-throw switch is connected in parallel to control the on / off state of the compensation network.
[0045] Length of Phase Shift Branch 1 Its phase shift ; length of phase-shifting branch two Its phase shift ,in, This is the phase constant corresponding to the center frequency.
[0046] A single-pole double-throw PIN switch controls the on / off state of RF1 and RFCom, and the on / off state of RF2 and RFCom, respectively, through bias voltages V1 and V2; the output terminal is connected to the single-pole double-throw switch RFCom, phase shift branch one is connected to RF1, and phase shift branch two is connected to RF2.
[0047] A single-pole single-throw PIN switch controls the conduction of RFin and RFout through a bias voltage V3; the second phase-shifting branch is connected to RFin, and the compensation network is connected to RFout.
[0048] The bias voltage V1 is reverse biased, and the output terminal of the single-pole double-throw switch is connected to the first phase-shifting branch; the bias voltage V2 is forward biased, and the output terminal of the single-pole double-throw switch is disconnected from the second phase-shifting branch; the bias voltage V3 is forward biased, the single-pole single-throw switch is connected, the compensation network is connected to the second phase-shifting branch, the second phase-shifting branch is effectively open at the input terminal, and the output signal is phase-shifted compared to the input signal. This is state three.
[0049] The bias voltage V1 is forward biased, and the output terminal of the single-pole double-throw switch is turned off from the first phase-shifting branch; the bias voltage V2 is reverse biased, and the output terminal of the single-pole double-throw switch is connected to the second phase-shifting branch; the bias voltage V3 is reverse biased, the single-pole single-throw switch is closed, the compensation network is disconnected from the second phase-shifting branch, the first phase-shifting branch is effectively open at the input terminal, and the output signal is phase-shifted. This is state four.
[0050] like Figure 6 As shown in the figure, the S-parameter simulation results curves for the second case are presented. Figure 6 a) represents the transmission coefficient S21 for states three and four. Figure 6 b) is the reflection coefficient S11 for states three and four. As can be seen from the figure, in the frequency band of f0-1.5~f0+1.5, f0 is the center frequency, the phase shifter insertion loss is less than 0.57dB, and the return loss is greater than 11dB. Figure 6 c) represents the phase delay for states three and four. Figure 6 d) is the phase difference between the two. It can be seen from the figure that the phase of state 3 lags behind the phase of state 4 by 90°. By controlling the switch to select the phase shift branch, 0° and 90° phase shifts can be achieved.
[0051] like Figure 7 As shown, the conventional switch selection linear phase shifter uses two single-pole double-throw switches, the same as those in the embodiment of this invention.
[0052] like Figure 8 As shown, the S-parameter characteristics of the present invention in state one and the conventional switch selection linear phase shifter when the phase shift branch one is turned on are further compared. Figure 8 a) is the transmission coefficient S21 of the present invention compared to the traditional switch-selective linear phase shifter. Figure 8 b) is the reflection coefficient S11 of the present invention compared to the traditional switch-selective linear phase shifter. Figure 8 c) The phase delay of this invention compared to a conventional switch-select linear phase shifter. Figure 8 d) represents the phase difference between the two. As shown in the figure, within the frequency band f0-1.5 to f0+1.5, where f0 is the center frequency, the insertion loss of this invention is less than 0.37 dB, and the return loss is greater than 18 dB. In contrast, the insertion loss of a traditional switch-selection linear phase shifter is less than 0.45 dB, and the return loss is greater than 22 dB. At the center frequency f0, the insertion loss of this invention is 0.22 dB better than that of a traditional switch-selection linear phase shifter. Furthermore, in terms of phase characteristics, the phase response of this invention is similar to that of a traditional switch-selection linear phase shifter, achieving phase shifting performance comparable to the traditional structure.
[0053] The compensation network in this embodiment can be a microstrip short-circuit stub, a microstrip open-circuit stub, a single-stub matcher, a multi-stub matcher, an RC circuit, an RLC circuit, etc. The compensation network affects the phase shifter bandwidth, insertion loss, return loss, etc.
[0054] like Figure 9 As shown, the two-position low-loss switch selection linear phase shifter, including two cascaded low-loss switch selection linear phase shifters, are both in the first case.
[0055] The first-stage low-loss switch selects the length of the phase shifting branch of the linear phase shifter. Its phase shift The length of phase-shifting branch two Its phase shift The compensation network is a short-circuit stub; the second-stage low-loss switch selects the length of the phase-shifting branch of the linear phase shifter. Its phase shift The length of phase-shifting branch two Its phase shift The compensation network is a microstrip short-circuit stub with a length of ,in, This is the phase constant corresponding to the center frequency.
[0056] Using phase-shifting branch one as the reference branch, reference Figure 1 In this manner, by controlling the first-stage single-pole double-throw switch and single-pole single-throw switch with bias voltage, the first-stage low-loss switch selection linear phase shifter can be shifted by 0° (state one) or 90° (state two); using phase shift branch one as the reference branch, the reference... Figure 1 By controlling the second-stage single-pole double-throw switch and single-pole single-throw switch with bias voltage, the second-stage low-loss switch selection linear phase shifter can be shifted by 0° (state one) or 45° (state two). Therefore, there are four phase states for the two-position low-loss switch selection linear phase shifter: 0° (first-stage state one * second-stage state one), 45° (state one * state two), 90° (state two * state one), and 135° (state two * state two).
[0057] like Figure 10 As shown, by controlling the two-stage low-loss switch to select the linear phase shifter, four states can be achieved: 0°, 45°, 90°, or 135° phase shift. Figure 10 a) Select the transmission coefficient S21 for the four states of the linear phase shifter for the two-position low-loss switch. Figure 10 b) Select the reflection coefficient S11 of the linear phase shifter for the two-position low-loss switch in four states. As can be seen from the figure, in the frequency band of f0-1.5~f0+1.5, f0 is the center frequency, the phase shifter insertion loss is less than 0.7dB, and the return loss is greater than 14dB. Figure 10 c) Select the phase delay for four states of the linear phase shifter for a two-position low-loss switch. Figure 10 d) Select the phase difference between the two low-loss switches and the reference phase 0° for the linear phase shifters at 45°, 90°, and 135°. As can be seen from the figure, the phase shifts of 0°, 45°, 90°, and 135° can be achieved by controlling the switch to select the phase shift branch.
[0058] like Figure 11 As shown, the phase shifter has an input terminal for RF input and an output terminal for RF output; bias voltage V1 is used to control the on / off state of phase shift branch one, bias voltage V2 is used to control the on / off state of phase shift branch two, and bias voltage V3 is used to control the on / off state of the compensation network.
[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present invention.
Claims
1. A low-loss switch-selection linear phase shifter, comprising a phase-shifting branch composed of two transmission lines of unequal length, wherein a single-pole double-throw switch is designed at the input or output end of the second phase-shifting branch, and a single-pole single-throw switch is designed at the input or output end of the third phase-shifting branch, characterized in that: Two phase-shifting branches are selected by a single-pole double-throw switch to achieve two different phase delays; the single-pole single-throw switch controls the on / off state of the compensation network.
2. The low-loss switch-selection linear phase shifter according to claim 1, characterized in that: Length of Phase Shift Branch 1 for ; length of phase-shifting branch two for ,in, For positive integers, phase-shifting branch one and phase-shifting branch two For one-to-one correspondence, The wavelength corresponding to the center frequency. The phase constant corresponding to the center frequency. The phase difference between phase-shifting branch one and phase-shifting branch two.
3. The low-loss switch-selection linear phase shifter according to claim 1, characterized in that: Single-pole double-throw switches and single-pole single-throw switches can be any of the following: PIN switches, electromagnetic relay switches, MEMS switches, or GaN HEMT switches.
4. The low-loss switch-selection linear phase shifter according to claim 1, characterized in that: A single-pole double-throw switch is designed for the input or output terminals of the two branches of a phase-shifting branch; The first scenario is: when the single-pole double-throw switch is at the input terminal, the single-pole single-throw switch is at the input terminal of phase-shifting branch two; The second scenario is: when the single-pole double-throw switch is at the output end, the single-pole single-throw switch is at the output end of phase-shifting branch two.
5. A low-loss switch-selection linear phase shifter according to claim 1 or 4, characterized in that: In the first scenario, the single-pole double-throw switch is at the input terminal, connecting the input terminal to phase-shifting branch one. When the single-pole double-throw switch is off from the input terminal to phase-shifting branch two, the single-pole double-throw switch is on, the compensation network is integrated into phase-shifting branch two, and phase-shifting branch two is effectively open at the output terminal. The output signal is phase-shifted compared to the input signal. This state is called state one; the single-pole double-throw switch is at the input terminal, the single-pole double-throw switch connects the input terminal and phase-shifting branch two, the single-pole double-throw switch disconnects the input terminal and phase-shifting branch one, the single-pole single-throw switch is closed, the compensation network is disconnected from phase-shifting branch two, phase-shifting branch one is effectively open at the output terminal, and the output signal is phase-shifted compared to the input signal. This state is called state two; In the second scenario, the single-pole double-throw switch is at the output terminal, and its output terminal is connected to phase-shifting branch one. The output terminal of the single-pole double-throw switch is also disconnected from phase-shifting branch two. When the single-pole double-throw switch is connected, the compensation network is integrated into phase-shifting branch two, which is effectively open at its input terminal. The output signal is phase-shifted compared to the input signal. This state is called state three; the single-pole double-throw switch is at the output terminal, the output terminal of the single-pole double-throw switch is connected to phase-shifting branch two, the output terminal of the single-pole double-throw switch is disconnected from phase-shifting branch one, the single-pole single-throw switch is closed, the compensation network is disconnected from phase-shifting branch two, phase-shifting branch one is equivalently open-circuited at the input terminal, and the output signal is phase-shifted compared to the input signal. This state is called state four.
6. The low-loss switch-selection linear phase shifter according to claim 1, characterized in that: The compensation network can be any one of the following: microstrip short-circuit stub, microstrip open-circuit stub, single-stub matching unit, multi-stub matching unit, RC circuit, or RLC circuit, and its phase... ; Specifically, the phase difference is At that time, no compensation network is needed, among which, It is a positive integer.
7. The low-loss switch-selection linear phase shifter according to claim 1, characterized in that: By cascading M low-loss switch-selected linear phase shifters, an M-position low-loss switch-selected linear phase shifter is obtained, and phase control is achieved through multiple switches. M-bit low-loss switch selector linear phase shifter, including M a The first scenario involves a low-loss switch selecting a linear phase shifter, M. b The second scenario involves a low-loss switch selection linear phase shifter, where M... a M b The integers are 0, 1, 2, ..., M, and M is a constant. a +M b =M; M≥2.
8. The low-loss switch-selection linear phase shifter according to claim 7, characterized in that: The M-position low-loss switch-selector linear phase shifter has a phase shifting branch length Li1 of its i-th stage low-loss switch-selector linear phase shifter as follows: The length of phase-shifting branch two, Li2, is ,in, For positive integers, phase-shifting branch one and phase-shifting branch two For one-to-one correspondence, The wavelength corresponding to the center frequency. The phase constant corresponding to the center frequency. The i-th stage low-loss switch selects the phase difference between phase shifting branch one and phase shifting branch two of the linear phase shifter.