He Wangdong, Chen Xi, Gong Jianhao, Hu Anyong, Miao Jungang
School of Electronics and Information Engineering, Beihang University, Beijing 100191, China.
Sensors (Basel). 2022 Jun 28;22(13):4877. doi: 10.3390/s22134877.
Six-port technology has been widely used in microwave systems, such as interferometric passive imaging. In this paper, an integrated Ka-band (32-36 GHz) six-port chip based on the 0.15-μm GaAs technology is designed and fabricated to simplify the circuit structure and miniaturize the volume of the imaging system. The designed chip integrates two amplifiers, two phase shifters, and a six-port circuit as part of an analog complex correlator. In this integrated chip, the crosstalk between the two amplifiers cannot be ignored. This paper analyzes the influence of the isolation between two amplifiers on the correlation results to guide the six-port chip design. In addition, considering that the radiometer system receives a broadband noise signal, the phase shifter needs to ensure that the phase shift range of each frequency point is the same under the same control conditions. Therefore, the phase shifter is designed with a high-pass and low-pass structure. The measurement results show that the isolation between the two amplifiers is greater than 20 dB, and the measured phase shift range and phase shift range error of the designed chip are 220° and 10°, respectively, with the control voltage varying from 0 to 1.5 V, which meets the requirements of the system.
六端口技术已广泛应用于微波系统，如干涉式被动成像。本文基于0.15μm砷化镓技术设计并制作了一款集成的Ka波段（32 - 36GHz）六端口芯片，以简化电路结构并使成像系统体积小型化。所设计的芯片集成了两个放大器、两个移相器以及一个作为模拟复相关器一部分的六端口电路。在这款集成芯片中，两个放大器之间的串扰不可忽视。本文分析了两个放大器之间的隔离度对相关结果的影响，以指导六端口芯片设计。此外，考虑到辐射计系统接收宽带噪声信号，移相器需要确保在相同控制条件下每个频率点的相移范围相同。因此，移相器采用高通和低通结构设计。测量结果表明，两个放大器之间的隔离度大于20dB，所设计芯片在控制电压从0到1.5V变化时，测得的相移范围和相移范围误差分别为220°和10°，满足系统要求。
