基于六端口网络的泄漏对消拓扑结构设计

设计了一种基于六端口网络的电路拓扑结构，可用来有效地抑制泄漏信号。该六端口网络主要由3个3 dB定向耦合器和一个不等分功分器组成。在与接收天线信号对应的2个输出端口，发射天线的泄漏信号经过移相后等幅且反向，使泄漏信号相互抵消，从而显著改善雷达网络收发天线之间的隔离性能。为验证该泄漏对消技术，设计并仿真验证了一种工作于22~26 GHz的电路拓扑结构。在工作频段上，该泄漏对消电路的隔离度小于-29.5 dB，并于中心频率处达到-44 dB的最大衰减。仿真结果证明，该电路可以有效提高单天线收发系统的隔离度，改善发射端到接收端的信号泄漏问题。

Design of a leakage canceller topology based on six-port network

A circuit topology based on six-port network is presented, which can be adopted to effectively suppress the leakage signal. This six-port network is mainly composed of three 3 dB hybrid couplers and an unequal Wilkinson power divider. Among the two output ports corresponding to the receiving signals, two leakage signals of the transmitting antenna are offset each other for their equal-magnitude and out-of-phase, which is benefit to achieve a high level of transmitting(Tx)-to-Rx isolation in the radar network. In order to demonstrate the Tx leakage canceller, a circuit topology is designed and simulated from 22 GHz to 26 GHz. In the operating band, the isolation of the Tx leakage canceller is lower than -29.5 dB, and it achieves the maximum isolation -44 dB at its center frequency. As shown, the circuit topology efficiently improves the isolation of single-antenna radar system and performs cancellation for the Tx leakage power.