CN110971211B

CN110971211B - Terahertz full 360-degree reflection type phase shifter

Info

Publication number: CN110971211B
Application number: CN201811136525.2A
Authority: CN
Inventors: 马建国; 李旭光; 周绍华; 赵升; 杨自凯; 杨闯; 张蕾; 李昭
Original assignee: Tianjin University Marine Technology Research Institute
Current assignee: Tianjin University Marine Technology Research Institute
Priority date: 2018-09-28
Filing date: 2018-09-28
Publication date: 2024-02-09
Anticipated expiration: 2038-09-28
Also published as: CN110971211A

Abstract

The terahertz full 360-degree reflection type phase shifter improves the insertion loss and phase shift range performance of the reflection type phase shifter through adjusting the structure of the reflection type phase shifter, and obtains the reflection type phase shifter with balanced power consumption and insertion loss and full 360-degree phase shift range. The phase shifter with the structure can be applied to millimeter wave/terahertz phased array systems.

Description

Terahertz full 360-degree reflection type phase shifter

Technical Field

The invention belongs to the field of millimeter wave/terahertz integrated circuits, and particularly relates to a terahertz full 360-degree reflection type phase shifter.

Background

The phased array technology has the functions of beam forming and beam scanning, so that the phased array technology has obvious advantages in communication systems, radars and other systems, can obviously improve the signal-to-noise ratio and sensitivity of the systems, and reduces the requirements on the power and noise of single equipment in the systems. Among them, the phase shifter is the most critical module in the phased array system, and it can change the phase of electromagnetic waves in the link so as to control the beam propagation direction. Phase shifters have a variety of implementations, which can be categorized as active and passive depending on whether energy is consumed. The active phase shifter is mainly a vector synthesis phase shifter, and a desired phase state is obtained by controlling the amplitude of two paths of quadrature signals and carrying out vector summation; the passive phase shifter mainly comprises a switch type phase shifter and a reflection type phase shifter, wherein the switch type phase shifter changes the phase through the on/off of different phase shifting units, and the reflection type phase shifter changes the phase of electromagnetic waves through changing the impedance of a load network.

Among these types of phase shifters, the reflective phase shifter consumes no power and is simple in structure. With the increase of the working frequency, the area of passive devices such as inductors in the reflective phase shifter is reduced, and the defect of large area consumption is greatly alleviated. Therefore, the reflective phase shifter becomes one of the better choices of the millimeter wave terahertz phased array system. However, the conventional reflective phase shifter has a small phase shift range, and is difficult to realize full 360 ° phase shift, which limits the scanning range of the phased array system.

Disclosure of Invention

In order to solve the problems in the prior art, the terahertz full 360-degree reflection type phase shifter disclosed by the invention has the advantages that the insertion loss and the phase shift range performance of the reflection type phase shifter are improved through adjusting the structure of the reflection type phase shifter, and the reflection type phase shifter with balanced power consumption and insertion loss and full 360-degree phase shift range is obtained. The phase shifter with the structure can be applied to millimeter wave/terahertz phased array systems.

The invention provides a terahertz full 360-degree phase shifter (shown in figure 1) which is realized by adopting a mode of combining a reflection type phase shifter and a 0/180-degree phase shifter and is based on a CMOS (complementary metal oxide semiconductor) process. In detail, as shown in fig. 2, the single-ended input signal is converted into a differential signal through balun T1 and is input into a 0 °/180 ° phase transformer. The 0 DEG/180 DEG phase transformer structure is similar to the Kerbert cell structure and consists of transconductance transistors M1 and M2 and differential transistors M3-M6. The differential signal output by T1 is input into the gates of the transconductance transistors M1 and M2, amplified and then output into the source stages of the differential transistors M3-M6 through the drain electrodes. VS is used as a control signal of the differential transistor and is matched with the inverter to control the switching states of M3-M6. The drains of M3-M6 are connected to transformer T2 as in the cross structure of FIG. 2 and output to the subsequent 3dB coupler input. In this process, VS will generate two states of 0 ° and 180 ° when at high level or low level, respectively, as a control signal. The reflective phase shifter structure consists of a 3dB coupler and a load pi-type network. The isolation end and the through end of the 3dB coupler are respectively connected with a pi-type load network consisting of C1, C2, L1, C3, C4 and L2. Wherein C1-C4 are variable capacitors, and the impedance change of a load network is realized by controlling the capacitance value of the variable capacitors through voltage, so that the phase change of the reflective phase shifter is realized. Finally, the 3dB coupler isolation terminal is the output of the entire circuit.

A terahertz full 360 DEG reflection phase shifter has the following advantages: first, the structure can expand the phase shift range of the traditional reflection phase shifter and realize the phase shift of full 360 degrees. Secondly, the phase shifter in the structure can obtain balanced state change under terahertz frequency, obtain effective gain, compensate the loss brought by a passive structure in the phase shifter, and enable the whole phase shifter structure to have smaller insertion loss.

Drawings

FIG. 1 is a terahertz full 360 phase shifter structural frame;

FIG. 2 is a schematic diagram of a terahertz full 360 phase shifter circuit;

fig. 3 is a conventional simple phase changer.

Detailed Description

The following detailed description of the present invention is based on the accompanying drawings, and the specific embodiments described herein are merely illustrative of the invention, but the scope of the invention is not limited to the embodiments.

A terahertz full 360 DEG reflection phase shifter is shown in a structural block diagram in fig. 1, adopts a structure of cascading a 0 DEG/180 DEG phase shifter and a reflection phase shifter, and realizes a full 360 DEG phase shifter with low insertion loss.

The detailed structure of the phase shifter is shown in fig. 2, the input terahertz signal is subjected to balun T1 to realize single-ended signal conversion and difference, and the obtained difference signals are respectively input into the gates of transconductance transistors M1 and M2 of the Kilbert structure. Drains of the M1 and the M2 are connected with sources of the differential transistors M3-M6, the M3-M6 serve as signal selection structures, drains of the differential transistors are connected to the transformer T2 in a crossing mode, and the control level VS and the inverter are used for achieving inversion of a phase changer signal path. When VS is forward biased, M3 and M6 are on, and the output state we define as 0 °; when VS is 0 bias, M4 and M5 are turned on, and the output state becomes 180 °. In addition, the transconductors M1 and M2 and the conducting differential tube form a quasi-cascode structure, and signal amplification can be obtained. When the 0 degree/180 degree phase shifter is realized, all NMOS transistors in the circuit adopt the minimum gate length dimension allowed by the process to obtain the optimal cut-off frequency of the transistors, and adopt a multi-gate structure to improve the structure gain. The phase transformer inputs the signal into the 3dB coupler through transformer T2. The load of the coupler adopts a pi-type load network, wherein C1-C4 are variable capacitors, L1 and L2 are inductors, the capacitance of the variable capacitors C1-C4 is changed by controlling the change of voltage, so that the change of load impedance is realized, the phase of a reflected signal is changed, and the change of a phase shift range larger than 180 degrees is realized. Finally, the phase of the phase changer 0 degree/180 degree turnover matching reflection type structure is larger than 180 degrees and continuously changes, and the full 360 degree phase shifting range can be realized.

Claims

1. A terahertz full 360 DEG reflection phase shifter is characterized in that: based on the CMOS technology, the terahertz full 360-degree phase shifter realized by adopting a mode of combining a reflection phase shifter and a 0/180-degree phase shifter has the following specific structure: the single-ended input signal is converted into a differential signal through the balun T1 and is input into a 0 degree/180 degree phase changer; the 0 degree/180 degree phase transformer structure consists of transconductance transistors M1 and M2 and differential transistors M3-M6; the differential signal output by the T1 is input into the grid electrodes of the transconductance transistors M1 and M2, and is amplified and then output into the source stages of the differential transistors M3-M6 through the drain electrodes; VS is used as a control signal of the differential transistor, and is matched with an inverter to control the switching states of M3-M6; the drains of M3-M6 are connected to the transformer T2 in a cross structure and output to the input end of the subsequent 3dB coupler; in this process, VS will generate two states of 0 ° and 180 ° when at high level or low level, respectively, as a control signal; the reflective phase shifter structure consists of a 3dB coupler and a load pi-type network; the isolation end and the through end of the 3dB coupler are respectively connected with a pi-type load network consisting of C1, C2, L1, C3, C4 and L2; wherein C1-C4 are variable capacitors, and the capacitance value is controlled by voltage to realize the impedance change of a load network and the phase change of the reflective phase shifter; finally, the 3dB coupler isolation terminal is the output of the entire circuit.