基于增强型微带耦合器组的全双工自干扰消除方法

Full-duplex Self-interference Cancellation Method Based on Enhanced Microstrip Coupler Group

自干扰消除技术是实现同时同频全双工通信的基础。在现有全双工天线系统的基础上,文中提出了一种新型的基于增强耦合器组的自干扰消除结构,该增强型耦合器组采用多支微带耦合器作为结构单元,具有良好的阻抗匹配和相位平衡性能,可以在大带宽范围内(500 MHz)实现超过40 dB的收发隔离度(中心频点为2.4 GHz)。进一步结合抽头式自干扰消除电路和宽带式贴片天线,文中提出的天线域模拟域联合自干扰消除方案最终可在120 MHz带宽上实现超过50 dB的自干扰消除。

Co-frequency co-time full-duplex(FD)communication can be achieved by mitigating the self-interference.After analyzing the existing full-duplex antenna systems,in this paper a novel enhanced self-interference cancellation(SIC)coupler group architecture is presented,which uses multiple microstrip couplers as structural units,and can achieve high isolation and wide bandwidth cancellation for single antenna FD communication.The presented hybrid coupler group adopts several microstrip hybrid couplers with good impedance matching and phase balance to achieve wideband isolation(almost 40 dB measured isolation centered at 2.4 GHz over 500 MHz bandwidth).Cooperating with multitap self-interference canceller and broadband patch antenna,the proposed antenna-analog domain joint SIC scheme can finally achieve 50 dB SIC over 120 MHz bandwidth.