Temperature compensated digital passive phase shifter
By introducing a temperature control unit into the digital passive phase shifter and adjusting the switching state of the switching unit, the problem of temperature-dependent passive phase shifters is solved, achieving performance stability and low power consumption over a wide temperature range, and improving the reliability and integration of the phased array system.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2021-12-26
- Publication Date
- 2026-04-07
AI Technical Summary
Traditional digital passive phase shifters are greatly affected by temperature, which impacts the performance of phased array systems. Furthermore, existing technologies struggle to compensate for temperature without increasing system insertion loss and control interfaces.
A temperature-compensated digital passive phase shifter was designed. By introducing a temperature control unit, the controlled switching unit is temperature-compensated. The switching state of the switching unit is adjusted by combining digital control signals and temperature control signals to compensate for temperature changes. The design includes a combination of a phase shifter, a controlled switching unit, and a temperature control unit.
It achieves constant phase, amplitude, and matching characteristics within a temperature range of -55 to 125°C, reduces power consumption, and improves integration without increasing system insertion loss or control interface.
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Figure CN114244309B_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of passive phase shifter, in particular to a temperature compensation digital passive phase shifter. BACKGROUND
[0002] As a key component in phased array system, phase shifter plays a decisive role in the performance of phased array system. Since a phased array system is equipped with a large number of phase shifters in the transceiver link, low cost, low power consumption, small size and light weight phase shifters are essential. Traditional phase shifters mostly use compound process, which has high electron mobility and high Q value of passive devices, low insertion loss, but high cost. Using silicon process can greatly reduce the cost, and digital and analog circuits can be integrated on the same die, thereby increasing the integration and reliability of the phased array system. According to the control mode, the phase shifter can be divided into analog phase shifter and digital phase shifter. The former can provide continuous phase shift with low insertion loss; the latter can provide a group of discrete phase shifts, which is not easy to be affected by noise on the control voltage and environmental temperature, and is more widely used. According to the device type, the phase shifter can be divided into active phase shifter and passive phase shifter. The former has a small area; the latter has low power consumption, large dynamic range and high linearity.
[0003] Digital passive phase shifter generally adopts switch network cascade, each stage is switched by switch to switch high / band pass branch or low pass branch, the phase difference of two branches is the phase shift of the stage, and the total phase shift is obtained by controlling the switching state of each stage. Since it uses passive devices and the transistor works in switch mode, the performance of the phase shifter is greatly affected by temperature, thereby affecting the performance of the entire phased array system. SUMMARY
[0004] The present application aims at the deficiencies of prior art, and provides a temperature compensation digital passive phase shifter, which does not increase the system insertion loss, does not affect the input and output matching, and does not additionally increase the control interface.
[0005] In order to achieve the purpose of the present application, the technical scheme adopted is as follows:
[0006] A temperature-compensated digital passive phase shifter includes a phase shifting unit, two controlled switching units, and a temperature control unit. The input of the first controlled switching unit is connected to an RF input port, and its output is connected to the input port of the phase shifting unit. The output port of the phase shifting unit is connected to the input of the second controlled switching unit, and the output of the second controlled switching unit is connected to an RF output port. A digital control signal Ctrl is connected to the temperature control unit. The output port of the temperature control unit is connected to the controlled ports of the two controlled switching units. The temperature control unit outputs a temperature control signal to the controlled switching units to perform temperature compensation on the characteristics of the controlled switching units. The temperature control unit processes the digital control signal to obtain a temperature control signal that varies with temperature and sends it to the controlled switching units. The RF signal is output after passing through the first controlled switching unit, the phase shifting unit, and the second controlled switching unit.
[0007] Furthermore, the phase shifting unit includes a high-pass / band-pass branch or a high-pass / low-pass branch. Each branch circuit consists of several passive devices such as inductors and capacitors. The phase shifting unit is used to generate the required phase shift, and the phase difference between the branches is the phase shift of the phase shifting unit.
[0008] Further details are attached. Figure 5 As shown, the phase-shifting unit includes two inductors: L1 and L2, and three capacitors: C1, C2, and C3; the positive terminal of C1 is connected to the input terminal of the upper branch, the negative terminal of C1 is connected to the positive terminal of L1, and the negative terminal of L2 is connected to the output terminal of the upper branch; the positive terminal of L2 is connected to the positive terminal of C2 and the input terminal of the lower branch, and the negative terminal of L2 is connected to the positive terminal of C3 and the output terminal of the lower branch; the negative terminals of C2 and C3 are grounded.
[0009] Furthermore, the controlled switching unit includes a series MOSFET structure and a parallel MOSFET structure. One set of series MOSFET structures and parallel MOSFET structures forms the upper branch, and another set of series MOSFET structures and parallel MOSFET structures forms the lower branch.
[0010] Furthermore, the controlled switch unit is used to select the two branches of the phase shifter. When the upper branch of the controlled switch unit is selected, the high-pass / band-pass branch of the phase shifter is connected to the circuit. When the lower branch of the controlled switch unit is selected, the low-pass branch of the phase shifter is connected to the circuit. The phase difference of the output signal in the two states is the phase shift of the phase shifter.
[0011] Further, the temperature control unit includes 9 transistors: P1 transistor, P2 transistor, P3 transistor, P4 transistor, P5 transistor, N1 transistor, N2 transistor, N3 transistor and N4 transistor, two resistors: R1 resistor and R2 resistor, two diodes: D1 diode and D2 diode, and one operational amplifier A1; the sources of the transistors P1, P2 and P3 are connected to the power supply simultaneously, the gates of the transistors P1, P2 and P3 are connected to the output terminal of the operational amplifier A1 simultaneously; the drain of P1 is connected to the gate and the drain of N1 simultaneously, the source of N1 is connected to the inverting input terminal of A1 and the anode of D1 simultaneously, and the cathode of D1 is grounded; the drain of P2 is connected to the gate and the drain of N2, and the source of N2 is connected to the non-inverting input terminal of A1 and the positive pole of R1; the negative pole of R1 is connected to the anode of D2, and the cathode of D2 is grounded; the drain of P3 is connected to the source of P4, the source of P5 and the positive pole of R2 simultaneously, and the negative pole of R2 is grounded; the gates of P4 and N3 are connected to the digital control signal Ctrl simultaneously; the drain of P4 is connected to the drain of N3, the gate of P5, the gate of N4 and the a output terminal of the temperature control unit simultaneously; the drain of P5 and the drain of N4 are connected to the b output terminal of the temperature control unit; and the sources of N3 and N4 are grounded.
[0012] Further, the controlled switch unit includes 8 transistors: M1, M2, M3, M4, M5, M6, M7 and M8, and 8 resistors: R1, R2, R3, R4, R5, R6, R7 and R8; the sources of M1 and M3 are connected to the input terminal simultaneously; the drain of M1 is connected to the source of M2, the gate of M1 is connected to the positive pole of R1, the gate of M2 is connected to the positive pole of R2, and the negative poles of R1 and R2 are connected to the controlled terminal a; the drain of M3 is connected to the source of M4, the gate of M3 is connected to the positive pole of R3, the gate of M4 is connected to the positive pole of R4, and the negative poles of R3 and R4 are connected to the controlled terminal b; the drain of M5 is connected to the drain of M2 and the upper branch output terminal, the source of M5 is connected to the drain of M6, the gate of M5 is connected to the positive pole of R5, the gate of M6 is connected to the positive pole of R6, the negative poles of R5 and R6 are connected to the controlled terminal b, and the source of M6 is grounded; the drain of M7 is connected to the drain of M4 and the lower branch output terminal, the source of M7 is connected to the drain of M8, the gate of M7 is connected to the positive pole of R7, the gate of M8 is connected to the positive pole of R8, the negative poles of R7 and R8 are connected to the controlled terminal a, and the source of M8 is grounded.
[0013] Further, the digital control signal Ctrl is input to the temperature control unit, the temperature control unit outputs a pair of inverse control signals at the output terminals a and b, and the signals change with temperature, which are used to control the switching state of the switch unit and compensate the temperature characteristics of the switch unit, so that the phase characteristics, amplitude characteristics and matching characteristics of the phase shifter are relatively constant in the temperature range of -55 to 125℃.
[0014] The temperature compensation digital passive phase shifter has the following advantages:
[0015] 1. By adding the temperature control unit, the phase characteristics, amplitude characteristics and matching characteristics of the whole phase shifter are compensated from -55 to 125℃ or even a wider temperature range.
[0016] 2. Since the control signal of the temperature compensation unit is generated by the on-chip circuit, the design does not increase the control interface, and has high integration.
[0017] 3. No additional circuit is added in the signal path, so the system insertion loss is not increased, and the system input and output matching is not affected.
[0018] 4. The temperature control unit has low power consumption, so the design is suitable for low-power applications. BRIEF DESCRIPTION OF DRAWINGS
[0019] 1. Figure 1 is a schematic diagram of a traditional phase shifter;
[0020] 2. Figure 2 is a structural schematic diagram of the temperature compensation digital passive phase shifter of the present application;
[0021] 3. Figure 3 is a schematic diagram of the temperature control unit of the present application;
[0022] 4. Figure 4 is a schematic diagram of the controlled switch unit of the present application;
[0023] 5. Figure 5 is a schematic diagram of the phase shift unit of the present application;
[0024] 6. Figure 6 is a comparison diagram of the phase, amplitude and matching performance of the traditional phase shifter and the temperature compensation phase shifter with temperature change;
[0025] 7. Figure 7 is the reduction rate of the temperature compensation phase shifter relative to the traditional phase shifter in amplitude characteristics, phase characteristics, input matching and output matching with temperature change. DETAILED DESCRIPTION
[0026] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.
[0027] Figure 1 is a schematic diagram of a traditional phase shifter; Figure 2 is a structural schematic diagram of the temperature compensation digital passive phase shifter of the present application; Figure 3 is a schematic diagram of the temperature control unit of the present application; Figure 4 is a schematic diagram of the controlled switch unit of the present application;Figure 5 This is a schematic diagram of the phase-shifting unit of the present invention; Figure 6 A comparison graph showing the phase, amplitude, and matching performance of a traditional phase shifter and a temperature-compensated phase shifter as a function of temperature; Figure 7 This refers to the rate of decrease in amplitude characteristics, phase characteristics, input matching, and output matching of temperature-compensated phase shifters compared to traditional phase shifters.
[0028] like Figure 2 As shown, this embodiment discloses a temperature-compensated digital passive phase shifter, including a phase shifting unit, two controlled switching units, and a temperature control unit. The input terminal of the first controlled switching unit is connected to an RF input port, and its output terminal is connected to the input port of the phase shifting unit. The output port of the phase shifting unit is connected to the input terminal of the second controlled switching unit, and the output terminal of the second controlled switching unit is connected to an RF output port. A digital control signal Ctrl is connected to the temperature control unit, and the output port of the temperature control unit is connected to the controlled ports of the two controlled switching units. The temperature control unit outputs a temperature control signal to the controlled switching units to compensate for their characteristics. The temperature control unit processes the digital control signal to obtain a temperature control signal that varies with temperature and sends it to the controlled switching units. The RF signal is output after passing through the first controlled switching unit, the phase shifting unit, and the second controlled switching unit.
[0029] The phase shifting unit includes a high-pass / band-pass branch or a high-pass / low-pass branch. Each branch circuit consists of several passive devices such as inductors and capacitors. The phase shifting unit is used to generate the required phase shift, and the phase difference between the branches is the phase shift of the phase shifting unit.
[0030] The controlled switching unit includes a series MOSFET structure and a parallel MOSFET structure. One set of series MOSFET structures and parallel MOSFET structures forms the upper branch, and another set of series MOSFET structures and parallel MOSFET structures forms the lower branch.
[0031] Furthermore, the controlled switch unit is used to select the two branches of the phase shifter unit and increase the isolation of the off branch. When the upper branch of the controlled switch unit is selected, the high-pass / band-pass branch of the phase shifter unit is connected to the circuit. When the lower branch of the controlled switch unit is selected, the low-pass branch of the phase shifter unit is connected to the circuit and the upper branch is turned off. The phase difference of the output signal in the two states is the phase shift of the phase shifter.
[0032] The temperature control unit generates control signals that change with temperature to compensate for the performance of the controlled switching unit.
[0033] In this preferred embodiment, such as Figure 3As shown, the temperature control unit includes nine transistors: P1, P2, P3, P4, P5, N1, N2, N3, and N4; two resistors: R1 and R2; two diodes: D1 and D2; and one operational amplifier A1. The sources of transistors P1, P2, and P3 are simultaneously connected to the power supply, and the gates of P1, P2, and P3 are simultaneously connected to the output of operational amplifier A1. The drain of P1 is simultaneously connected to both the gate and drain of N1, and the source of N1 is simultaneously connected to the inverting input of A1 and the anode of D1. The cathode of D1 is grounded; the drain of P2 is connected to the gate and drain of N2, and the source of N2 is connected to the non-inverting input of A1 and the positive terminal of R1; the negative terminal of R1 is connected to the anode of D2, and the cathode of D2 is grounded; the drain of P3 is connected to the source of P4, the source of P5, and the positive terminal of R2, and the negative terminal of R2 is grounded; the gates of P4 and N3 are connected to the digital control signal Ctrl; the drain of P4 is connected to the drain of N3, the gate of P5, the gate of N4, and the a output port of the temperature control unit; the drains of P5 and N4 are connected to the b output port of the temperature control unit; the sources of N3 and N4 are grounded.
[0034] like Figure 4 As shown, the controlled switch unit in this embodiment includes eight transistors: M1, M2, M3, M4, M5, M6, M7, and M8, and eight resistors: R1, R2, R3, R4, R5, R6, R7, and R8. The sources of M1 and M3 are simultaneously connected to the input port; the drain of M1 is connected to the source of M2, the gate of M1 is connected to the positive terminal of R1, the gate of M2 is connected to the positive terminal of R2, and the negative terminals of R1 and R2 are connected to the controlled port a; the drain of M3 is connected to the source of M4, the gate of M3 is connected to the positive terminal of R3, and the gate of M4 is connected to the negative terminal of R4. The positive terminal of M5 and the negative terminals of R3 and R4 are connected to the controlled port b; the drain of M5 is connected to the drain of M2 and the upper branch output terminal, the source of M5 is connected to the drain of M6, the gate of M5 is connected to the positive terminal of R5, the gate of M6 is connected to the positive terminal of R6, the negative terminals of R5 and R6 are connected to the controlled port b, and the source of M6 is grounded; the drain of M7 is connected to the drain of M4 and the lower branch output terminal, the source of M7 is connected to the drain of M8, the gate of M7 is connected to the positive terminal of R7, the gate of M8 is connected to the positive terminal of R8, the negative terminals of R7 and R8 are connected to the controlled port a, and the source of M8 is grounded.
[0035] like Figure 5 As shown, the phase-shifting unit in this embodiment includes two inductors: L1 and L2, and three capacitors: C1, C2, and C3; the positive terminal of C1 is connected to the input terminal of the upper branch, the negative terminal of C1 is connected to the positive terminal of L1, and the negative terminal of L2 is connected to the output terminal of the upper branch; the positive terminal of L2 is connected to the positive terminal of C2 and the input terminal of the lower branch, and the negative terminal of L2 is connected to the positive terminal of C3 and the output terminal of the lower branch; the negative terminals of C2 and C3 are grounded.
[0036] In this embodiment, the digital control signal Ctrl is sent to the temperature control circuit to generate a pair of opposite control signals a and b, the low level is 0V, and the high level depends on the voltage of X point. The temperature control circuit can make the voltage of X point rise with the temperature, so that the on-resistance of the switch tubes M1~8 in the controlled switch unit tends to be constant at different temperatures. The on-resistance of the switch tube is the biggest factor affecting the performance of the phase shifter, so the amplitude characteristic, phase characteristic and matching characteristic of the phase shifter can be temperature compensated. In this example, the best compensation characteristic is obtained by adjusting the sizes of diode D1, diode D2, resistor R1 and resistor R2.
[0037] As shown in the accompanying Figure 6 The amplitude characteristic, phase characteristic, input matching and output matching of the conventional phase shifter and the temperature-compensated phase shifter are simulated and compared, and the curves of the temperature variation of the characteristics are shown in the figure. The solid line in the figure is the characteristic of the temperature-compensated phase shifter, and the dashed line is the characteristic of the conventional phase shifter. As can be seen from the figure, the performances of the temperature-compensated phase shifter are all temperature-compensated, and the amplitude characteristic is reduced from 364.6mdB to 98mdB, with a reduction of 73%.
[0038] As shown in the accompanying Figure 7 The figure shows the reduction rates of the amplitude characteristic, phase characteristic, input matching and output matching of the temperature-compensated phase shifter relative to the conventional phase shifter with the temperature variation. It can be seen that the reduction rates of the four characteristics with the temperature variation are 73.12%, 56.39%, 33.33% and 38.14% respectively. The first two characteristics are particularly important for the phase shifter, and their change reduction rates are also the largest, which reflects the advantages of the present application.
[0039] So far, the technical solutions of the present application have been described in combination with the preferred embodiments, but those skilled in the art can easily understand that the protection scope of the present application is obviously not limited to these specific embodiments. Those skilled in the art can make equivalent changes or replacements to the related technical features without departing from the principles of the present application, and the technical solutions after the changes or replacements will all fall within the protection scope of the present application.
Claims
1. A temperature-compensated digital passive phase shifter, characterized in that: The system includes a phase-shifting unit, two controlled switching units, and a temperature control unit. The input of the first controlled switching unit is connected to the RF input port, and its output is connected to the input port of the phase-shifting unit. The output port of the phase-shifting unit is connected to the input of the second controlled switching unit, and the output of the second controlled switching unit is connected to the RF output port. A digital control signal Ctrl is connected to the temperature control unit. The output port of the temperature control unit is connected to the controlled ports of the two controlled switching units. The temperature control unit outputs a temperature control signal to the controlled switching units to perform temperature compensation on the characteristics of the controlled switching units. The temperature control unit processes the digital control signal to obtain a temperature control signal that varies with temperature. The signal is transmitted to the controlled switching unit. The radio frequency signal is output after passing through the first controlled switching unit, the phase shifting unit, and the second controlled switching unit. The controlled switching unit includes a series MOSFET structure and a parallel MOSFET structure. One set of series MOSFET structures and parallel MOSFET structures forms the upper branch, and another set of series MOSFET structures and parallel MOSFET structures forms the lower branch. The controlled switching unit is used to select the two branches of the phase shifting unit. When the upper branch of the controlled switching unit is selected, the high-pass / band-pass branch of the phase shifting unit is connected to the circuit. When the lower branch of the controlled switching unit is selected, the low-pass branch of the phase shifting unit is connected to the circuit. The phase difference of the output signal in the two states is the phase shift of the phase shifter. The temperature control unit includes nine transistors: P1, P2, P3, P4, P5, N1, N2, N3, and N4; two resistors: R1 and R2; two diodes: D1 and D2; and an operational amplifier A1. The sources of transistors P1, P2, and P3 are simultaneously connected to the power supply, and their gates are simultaneously connected to the output of operational amplifier A1. The drain of P1 is simultaneously connected to the gate and drain of N1, and the source of N1 is simultaneously connected to the inverting input of A1 and the anode of D1. The cathode of D1 is grounded. The drain of P2 is connected to the gate and drain of N2, and the source of N2 is connected to the non-inverting input of A1 and the positive terminal of R1. The negative terminal of R1 is connected to the anode of D2. The cathode of P3 is grounded; the drain of P3 is simultaneously connected to the source of P4, the source of P5, and the positive terminal of R2, while the negative terminal of R2 is grounded; the gates of P4 and N3 are simultaneously connected to the digital control signal Ctrl; the drain of P4 is simultaneously connected to the drain of N3, the gate of P5, the gate of N4, and the a output port of the temperature control unit; the drains of P5 and N4 are connected to the b output port of the temperature control unit; the sources of N3 and N4 are grounded; the phase shifting unit includes two inductors: L1 and L2, and three capacitors: C1, C2, and C3; the positive terminal of C1 is connected to the input terminal of the upper branch, the negative terminal of C1 is connected to the positive terminal of L1, and the negative terminal of L2 is connected to the output terminal of the upper branch; the positive terminal of L2 is connected to the positive terminal of C2 and the input terminal of the lower branch, and the negative terminal of L2 is connected to the positive terminal of C3 and the output terminal of the lower branch; the negative terminals of C2 and C3 are grounded; The controlled switching unit includes eight transistors: M1, M2, M3, M4, M5, M6, M7, and M8, and eight resistors: R1, R2, R3, R4, R5, R6, R7, and R8. The sources of M1 and M3 are simultaneously connected to the input port. The drain of M1 is connected to the source of M2, the gate of M1 is connected to the positive terminal of R1, the gate of M2 is connected to the positive terminal of R2, and the negative terminals of R1 and R2 are connected to the controlled port a. The drain of M3 is connected to the source of M4, the gate of M3 is connected to the positive terminal of R3, and the gate of M4 is connected to the positive terminal of R4. The negative terminals of R3 and R4 are connected to the controlled port b; the drain of M5 is connected to the drain of M2 and the upper branch output terminal, the source of M5 is connected to the drain of M6, the gate of M5 is connected to the positive terminal of R5, the gate of M6 is connected to the positive terminal of R6, the negative terminals of R5 and R6 are connected to the controlled port b, and the source of M6 is grounded; the drain of M7 is connected to the drain of M4 and the lower branch output terminal, the source of M7 is connected to the drain of M8, the gate of M7 is connected to the positive terminal of R7, the gate of M8 is connected to the positive terminal of R8, the negative terminals of R7 and R8 are connected to the controlled port a, and the source of M8 is grounded.
2. The temperature-compensated digital passive phase shifter according to claim 1, characterized in that: The phase-shifting unit includes a high-pass / band-pass branch or a high-pass / low-pass branch, and each branch circuit consists of several inductors and capacitors.
3. The temperature-compensated digital passive phase shifter according to claim 1, characterized in that: The digital control signal Ctrl is input to the temperature control unit. The output ports a and b of the temperature control unit output a pair of inverse control signals, which change with the temperature and are used to control the switching state of the switching unit. At the same time, the temperature characteristics of the switching unit are compensated so that the phase characteristics, amplitude characteristics and matching characteristics of the phase shifter are relatively constant in the temperature range of -55 to 125℃.
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