一种新型路径共享真时延波束合成架构的设计

Design of a new path-sharing true-time-delay beamformer architecture

为满足宽带天线通信系统多输入多输出的要求,提出了一种新型路径共享真时延波束合成架构。通过真时延单元提供的一定延时差弥补信号到达天线的时间差,合成多路信号来提高输出能力。相比于传统的波束合成架构,该架构通过真时延单元共享,节省芯片面积。该架构具有中心对称性与可扩展性,可支持2M个输入和2K个输出。基于HHNEC0. 18μm CMOS工艺设计四入四出波束合成器单元,对提出的架构加以验证。仿真结果表明,工作频带为0. 5~1. 5 GHz,延时分辨率为80 ps、最大延时为720 ps。在天线间距为10. 5 cm的情况下,能够提供±43°和±13°四个扫描角度。输入输出回波损耗≤-10 dB,带内整体增益为约26 dB,增益平坦度≤3 dB。版图面积(包括I/O焊盘和ESD)为3. 69 mm×3. 62 mm。

In order to meet the requirement of multi-input and multi-output of broadband wireless communication system,a new path-sharing true-time-delay beamformer architecture is proposed in this paper.The output capability is improved by synthesizing multiple signals,compensating the time difference in reaching the antenna with a certain delay difference provided by the true-time-delay unit.Compared with the traditional beamformer architecture,this architecture can save the area of chip by true-time-delay unit sharing.It is not only extensional,supporting 2 M antennas and synthesizing 2 K signal beams,but also symmetrical.Based on HHNEC 0.18μm CMOS process,four-in-four-out beamformer is designed to verify the proposed architecture.The simulation results show that this beamformer works over 0.5-1.5 GHz and has four antennas,with delay resolution of 80 ps and maximum delay of 720 ps.It can provide four scanning angles of±43°and±13°for four antennas with 10.5 cm spacing.The input-output return loss is not more than-10 dB,the gain is about26 dB,and gain flatness is not more than 3 dB.The layout area(including I/O pad and ESD)is 3.69 mm×3.62 mm.