Millimeter-wave low-loss phase-shifting circuit

Abstract

The present invention discloses a millimeter wave low-loss phase-shifting circuit, which includes a first single-pole double-throw switch circuit, a second single-pole double-throw switch circuit, a low-pass filter circuit, and a band-pass filter circuit. The present invention utilizes the phase-advanced characteristic of the high-pass element to reasonably select the order of the reference state high-pass element, which can achieve a wider phase-frequency characteristic bandwidth, and introduces parallel resonance in the band-pass filter circuit to improve the high-frequency phase bandwidth. The single-pole double-throw switch circuit is matched with the phase-shifting network design to achieve smaller insertion loss and area. The phase-shifting circuit has the characteristics of wide phase-frequency characteristics, low loss, simple circuit topology, low process difficulty requirements, and stable performance.

Description

Technical Field

[0001] The invention belongs to the field of radio frequency microwave integrated circuits of microelectronics and solid electronics, and relates to a phase shift circuit, in particular to a millimeter wave low-loss phase shift circuit. Background Art

[0002] Phase shifters are devices used to control the phase change of microwave signals. They are key components in phased array radars and digital microwave communication systems. The antenna beam scanning is controlled by the phase change of the phase shifter. Therefore, the performance of the phase shifter, such as size, phase shift accuracy, cost, operating temperature, and mass production capacity, are directly related to the performance of the entire phased array radar and play a vital role in the entire radar system.

[0003] Currently, the monolithic integrated phase shifter circuits that can achieve large phase shifts are mainly transmission type and reflection type. Reflection type phase shifters can achieve a wider bandwidth, but the quarter-wavelength line occupies a larger area, and the reflection type phase shifter is sensitive to process tolerances, which is not conducive to mass production. The commonly used structures of transmission type phase shifters are high-pass and low-pass structures and all-pass structures. The high-pass and low-pass structure phase shifters have a narrow operating frequency band and large losses, especially in the K and Ka bands. The all-pass structure phase shifter has a wide bandwidth, but the loss and area are larger, and it has no advantages in some applications where bandwidth requirements are not high. Summary of the invention

[0004] In order to solve the technical problems mentioned in the above background technology, the present invention proposes a millimeter-wave low-loss phase-shifting circuit to solve the problem of balancing bandwidth, loss, and process tolerance. Especially in the K and Ka frequency bands, a millimeter-wave low-loss phase-shifting circuit is designed. The phase-shifting circuit can not only achieve a wider phase-frequency characteristic, smaller loss and smaller area, but also has stable performance and is conducive to mass production.

[0005] In order to achieve the above technical objectives, the technical solution of the present invention is:

[0006] A millimeter wave low-loss phase shift circuit, which is used for a 90° phase shift circuit, comprises a first single-pole double-throw switch circuit, a second single-pole double-throw switch circuit, a low-pass filter circuit and a band-pass filter circuit; wherein the first single-pole double-throw switch circuit comprises a first switch tube, a second switch tube and a third switch tube, the second single-pole double-throw switch circuit comprises a fourth switch tube, a fifth switch tube and a sixth switch tube, the low-pass filter circuit comprises a first inductor, a second inductor and a first capacitor, the band-pass filter circuit comprises a first microstrip line, a second microstrip line, a second capacitor and a third inductor, the gates of the first, third, fourth and sixth switch tubes are input with a forward voltage, and the gates of the second and fifth switch tubes are input with a reverse voltage; wherein the first end of the first switch tube is connected in series The first inductor and the second inductor are connected to the first end of the fourth switch tube, and the second end of the fourth switch tube is connected to the fifth switch tube and the sixth switch tube connected in sequence and then grounded; the second end of the first switch tube is connected to the second switch tube and the third switch tube in sequence and then grounded; the common end of the first inductor and the second inductor is connected to the first capacitor and then grounded; the common end of the first switch tube and the second switch tube is connected to the first signal channel, and the common end of the fourth switch tube and the fifth switch tube is connected to the second signal channel; the common end of the second switch tube and the third switch tube is connected in series with the first microstrip line and the second microstrip line, and then connected to the common end of the fifth switch tube and the sixth switch tube; wherein the common end of the first microstrip line and the second microstrip line is connected to the third inductor and the second capacitor connected in parallel and then grounded.

[0007] Preferably, the first single-pole double-throw switch circuit and the second single-pole double-throw switch circuit select one of the low-pass filter circuit and the band-pass filter circuit as the signal transmission path by applying a control voltage to the gate of the switch tube.

[0008] Preferably, the switch tube is a field effect tube.

[0009] A millimeter wave low-loss phase shift circuit, which is used for a 180° phase shift circuit, comprises a first single-pole double-throw switch circuit, a second single-pole double-throw switch circuit, a low-pass filter circuit and a band-pass filter circuit; wherein the first single-pole double-throw switch circuit element comprises a seventh switch tube and an eighth switch tube; the second single-pole double-throw switch circuit element comprises a ninth switch tube and a tenth switch tube; the low-pass filter circuit element comprises a fourth inductor, a fifth inductor, a sixth inductor, a third capacitor and a fourth capacitor; the band-pass filter circuit element comprises a seventh inductor, an eighth inductor, a ninth inductor, a fifth capacitor, a sixth capacitor and a seventh capacitor; the seventh and ninth switch tubes are gated to input a forward voltage, and the eighth and tenth switch tubes are gated to input a reverse voltage; wherein the first end of the seventh switch tube is connected in series The fourth inductor, the fifth inductor and the sixth inductor are then connected to the first end of the ninth switch tube, the second end of the seventh switch tube is connected to the first end of the eighth switch tube, the second end of the eighth switch tube is connected to the seventh inductor, the fifth capacitor, the sixth capacitor and the eighth inductor which are connected in sequence, and then connected to the second end of the tenth switch tube, the first end of the tenth switch tube is connected to the second end of the ninth switch tube, wherein the common end of the fourth inductor and the fifth inductor is connected to the third capacitor and then to ground; the common end of the fifth inductor and the sixth inductor is connected to the fourth capacitor and then to ground, the common end of the fifth capacitor and the sixth capacitor is connected to the ninth inductor and the seventh capacitor in parallel and then to ground, the common end of the seventh switch tube and the eighth switch tube is connected to the first signal channel, and the common end of the ninth switch tube and the tenth switch tube is connected to the second signal channel.

[0010] Preferably, the first single-pole double-throw switch circuit and the second single-pole double-throw switch circuit select one of the low-pass filter circuit and the band-pass filter circuit as the signal transmission path by applying a control voltage to the gate of the switch tube.

[0011] Preferably, the switch tube is a field effect tube.

[0012] Beneficial effects of adopting the above technical solution: combined with examples

[0013] (1) Improve the reference high-pass network in the traditional high-pass and low-pass phase shift circuit to a band-pass network. The core idea is to use the phase advance characteristics of the high-pass element to reasonably select the order of the high-pass element, that is, to use the band-pass filter structure to replace the high-pass filter structure in the traditional high-pass and low-pass phase shift circuit, thereby widening the bandwidth of the phase-frequency characteristic. On the other hand, parallel resonance is introduced into the band-pass filter structure to improve the high-frequency phase flatness and widen the bandwidth of the phase-frequency characteristic.

[0014] (2) The switch and phase shift network are designed together to reduce loss and area. By switching the switch to select the reference state and phase shift state of the phase shifter, a wider phase-frequency characteristic bandwidth can be achieved, while achieving low loss and miniaturization. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of a 90° phase shift circuit in the 28-42 GHz frequency band according to an embodiment of the present invention.

[0016] Figure 2 It is a schematic diagram of a 180° phase shift circuit in the 28-42 GHz frequency band according to an embodiment of the present invention.

[0017] Figure 3 to Figure 5 It is a simulation curve of the 90° phase shift circuit in the 28-42 GHz frequency band of the embodiment of the present invention.

[0018] Figure 6 to Figure 8 It is a simulation curve of the 180° phase shift circuit in the 28-42 GHz frequency band of an embodiment of the present invention. DETAILED DESCRIPTION

[0019] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings.

[0020] The phase shift circuit of this embodiment works in the 28-42 GHz frequency band, including 90° and 180° phase shift circuits, wherein the schematic diagram of the 90° phase shift circuit is as shown in FIG. Figure 1 As shown, the schematic diagram of the 180° phase shift circuit is as follows Figure 2 shown.

[0021] The switch tube M described in this example is a depletion type FET tube. When a -5V voltage is applied to Vgs or Vgd, the switch tube is in a cut-off state. When a 0V voltage is applied to Vgs or Vgd, the switch tube is in a conducting state. Where g is the gate of the FET tube, d is the drain of the FET tube, and s is the source of the FET tube.

[0022] like Figure 1 In the 90° phase-shift circuit shown, the asymmetric structure of the switch and the overall design of the phase-shift circuit can achieve lower losses. The first-order high-pass element inductor L3 in the reference state band-pass filter circuit provides a basic phase shift of 90° ahead. The inductor L3 and the capacitor C2 form a parallel resonance to widen the high-frequency phase bandwidth.

[0023] The phase shift circuit includes a first single-pole double-throw switch circuit, a second single-pole double-throw switch circuit, a low-pass filter circuit, and a band-pass filter circuit. By switching the first single-pole double-throw switch circuit and the second single-pole double-throw switch circuit, one of the low-pass filter circuit and the band-pass filter circuit can be selected as a signal transmission path to achieve relative phase shift.

[0024] The first single-pole double-throw switch circuit adopts an asymmetric structure design, including switch tube M1, switch tube M2, and switch tube M3. The input end of the first single-pole double-throw switch circuit is connected to the input end of the phase shifter, one end of the output end is connected to the low-pass filter circuit, and the other end is connected to the band-pass filter circuit.

[0025] The second single-pole double-throw switch circuit adopts an asymmetric structure design, including switch tubes M4, M5, and M6. The output end of the second single-pole double-throw switch circuit is connected to the output end of the phase shifter, one end of the input end is connected to the low-pass filter circuit, and the other end is connected to the band-pass filter circuit.

[0026] The low-pass filter circuit provides a lagging phase and includes a first inductor L1, a first capacitor C1, and a second inductor L2. One end of the first inductor L1 and one end of the second inductor L2 serve as the input and output ends of the low-pass filter circuit, respectively. The input end of the low-pass filter circuit is connected to the output end of the switch tube M1 of the first single-pole double-throw switch circuit, and the output end of the low-pass filter circuit is connected to the input end of the switch tube M4 of the second single-pole double-throw switch circuit.

[0027] The bandpass filter circuit provides an advanced phase, and includes a first microstrip line LIN1, a second microstrip line LIN2, a second capacitor C2, and a third inductor L3. One end of the first microstrip line LIN1 and one end of the second microstrip line LIN2 serve as the input and output ends of the bandpass filter circuit, respectively. The input end of the bandpass filter circuit is connected to the output end of the switch tube M2 of the first single-pole double-throw switch circuit, and the output end of the low-pass filter circuit is connected to the input end of the switch tube M5 of the second single-pole double-throw switch circuit.

[0028] 180° phase shift principle diagram Figure 2 As shown, a larger phase shift amount can be achieved by reasonably increasing the order of components in the reference state and the phase shift state, and a lower loss can be achieved by a reasonable design of a single-pole double-throw switch circuit.

[0029] The phase shift circuit includes a first single-pole double-throw switch circuit, a second single-pole double-throw switch circuit, a low-pass filter circuit, and a band-pass filter circuit. By switching the first single-pole double-throw switch circuit and the second single-pole double-throw switch circuit, one of the low-pass filter circuit and the band-pass filter circuit can be selected as a signal transmission path to achieve relative phase shift.

[0030] The first single-pole double-throw switch circuit adopts a pure series tube symmetrical structure design, including a switch tube M7 and a switch tube M8. The input end of the first single-pole double-throw switch circuit is connected to the input end of the phase shifter, one end of the output end is connected to the low-pass filter circuit, and the other end is connected to the band-pass filter circuit.

[0031] The second single-pole double-throw switch circuit adopts a pure series tube symmetrical structure design, including a switch tube M9 and a switch tube M10. The output end of the second single-pole double-throw switch circuit is connected to the output end of the phase shifter, one end of the input end is connected to the low-pass filter circuit, and the other end is connected to the band-pass filter circuit.

[0032] The low-pass filter circuit provides a lagging phase, and includes a third inductor L3, a third capacitor C3, a fourth capacitor C4, a fourth inductor L4, and a fifth inductor L5. One end of the third inductor L3 and one end of the fifth inductor L5 serve as the input and output ends of the low-pass filter circuit, respectively. The input end of the low-pass filter circuit is connected to the output end of the switch tube M7 of the first single-pole double-throw switch circuit, and the output end of the low-pass filter circuit is connected to the input end of the switch tube M9 of the second single-pole double-throw switch circuit.

[0033] The band-pass filter circuit provides an advanced phase, and includes a sixth inductor L6, a fifth capacitor C5, a sixth capacitor C6, a seventh inductor L7, an eighth inductor L8, and a seventh capacitor C7. One end of the sixth inductor L6 and one end of the seventh inductor L7 serve as the input and output ends of the band-pass filter circuit, respectively. The input end of the band-pass filter circuit is connected to the output end of the switch tube M8 of the first single-pole double-throw switch circuit, and the output end of the low-pass filter circuit is connected to the input end of the switch tube M10 of the second single-pole double-throw switch circuit.

[0034] Figure 3 to Figure 8 is the simulation curve of the 28-42 GHz phase shift circuit of the present invention, Figure 3 is a 90 degree phase shift curve, Figure 4 Insertion loss for a 90 degree phase shift, Figure 5 The input and output standing waves are 90 degrees phase shifted. Figure 6 is a 180 degree phase shift curve, Figure 7 Insertion loss for a 180 degree phase shift, Figure 8 It is a 180-degree phase shift input and output standing wave. As can be seen from the figure, within the 28-42GHz frequency band, the phase shift accuracy of this structure phase shifter is very high, the flatness is good, the phase shift error of 90-degree and 180-degree phase shift is less than 0.4°, and the loss is low.

[0035] about Figure 3 to Figure 8 Explanation of the markings in the simulation curves: In the insertion loss curve, state 0 represents the reference state, and state 1 represents the phase-shifted state; in the input and output standing wave curves, state0 represents the reference state, state1 represents the phase-shifted state, i represents the input end, and o represents the output end.

[0036] The embodiments are only for illustrating the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the present invention.

Claims

1. A millimeter wave low-loss phase shift circuit, characterized in that: The circuit is used for a 90° phase shift circuit, and the circuit includes a first single-pole double-throw switch circuit, a second single-pole double-throw switch circuit, a low-pass filter circuit and a band-pass filter circuit; wherein the first single-pole double-throw switch circuit includes a first switch tube, a second switch tube and a third switch tube, the second single-pole double-throw switch circuit includes a fourth switch tube, a fifth switch tube and a sixth switch tube, the low-pass filter circuit includes a first inductor, a second inductor and a first capacitor, the band-pass filter circuit includes a first microstrip line, a second microstrip line, a second capacitor and a third inductor, the gates of the first, third, fourth and sixth switch tubes are input with a forward voltage, and the gates of the second and fifth switch tubes are input with a reverse voltage; wherein the first end of the first switch tube is connected in series with the first inductor and the first end of the second switch tube. The first and second inductors are connected to the first end of the fourth switch tube, and the second end of the fourth switch tube is connected to the fifth and sixth switch tubes connected in sequence and then grounded; the second end of the first switch tube is connected to the second and third switch tubes in sequence and then grounded; the common end of the first inductor and the second inductor is connected to the first capacitor and then grounded; the common end of the first switch tube and the second switch tube is connected to the first signal channel, and the common end of the fourth switch tube and the fifth switch tube is connected to the second signal channel; the common end of the second switch tube and the third switch tube is connected in series with the first microstrip line and the second microstrip line, and then connected to the common end of the fifth switch tube and the sixth switch tube; wherein the common end of the first microstrip line and the second microstrip line is connected to the third inductor and the second capacitor in parallel and then grounded.

2. A millimeter wave low-loss phase shift circuit according to claim 1, characterized in that: The first single-pole double-throw switch circuit and the second single-pole double-throw switch circuit select one of the low-pass filter circuit and the band-pass filter circuit as a signal transmission path by applying a control voltage to the gate of the switch tube.

3. A millimeter wave low-loss phase shift circuit according to claim 2, characterized in that: The switch tube is a field effect tube.

4. A millimeter wave low-loss phase shift circuit, characterized in that: The circuit is used for a 180° phase shift circuit, and the circuit comprises a first single-pole double-throw switch circuit, a second single-pole double-throw switch circuit, a low-pass filter circuit and a band-pass filter circuit; wherein the first single-pole double-throw switch circuit element comprises a seventh switch tube and an eighth switch tube; the second single-pole double-throw switch circuit element comprises a ninth switch tube and a tenth switch tube; the low-pass filter circuit element comprises a fourth inductor, a fifth inductor, a sixth inductor, a third capacitor and a fourth capacitor; the band-pass filter circuit element comprises a seventh inductor, an eighth inductor, a ninth inductor, a fifth capacitor, a sixth capacitor and a seventh capacitor; the seventh and ninth switch tubes are gated to input a forward voltage, and the eighth and tenth switch tubes are gated to input a reverse voltage; wherein the first end of the seventh switch tube is connected in series to the fourth inductor, the sixth inductor and the seventh inductor; The fifth inductor and the sixth inductor are connected to the first end of the ninth switch tube, the second end of the seventh switch tube is connected to the first end of the eighth switch tube, the second end of the eighth switch tube is connected to the seventh inductor, the fifth capacitor, the sixth capacitor and the eighth inductor which are connected in sequence, and then connected to the second end of the tenth switch tube, the first end of the tenth switch tube is connected to the second end of the ninth switch tube, wherein the common end of the fourth inductor and the fifth inductor is connected to the third capacitor and then to ground; the common end of the fifth inductor and the sixth inductor is connected to the fourth capacitor and then to ground, the common end of the fifth capacitor and the sixth capacitor is connected to the ninth inductor and the seventh capacitor in parallel and then to ground, the common end of the seventh switch tube and the eighth switch tube is connected to the first signal channel, and the common end of the ninth switch tube and the tenth switch tube is connected to the second signal channel.

5. A millimeter wave low-loss phase shift circuit according to claim 4, characterized in that: The first single-pole double-throw switch circuit and the second single-pole double-throw switch circuit select one of the low-pass filter circuit and the band-pass filter circuit as a signal transmission path by applying a control voltage to the gate of the switch tube.

6. A millimeter wave low-loss phase shift circuit according to claim 5, characterized in that: The switch tube is a field effect tube.

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