有限量化精度移相器对毫米波平面相阵波束控制性能的影响

Influence of Finite Quantization Phase Shifter on Performance of Millimeter-wave Planar Phased Array Beam Steering

在毫米波频段由于路径损耗较大,通常采用波束成形来提高链路增益以建立稳定的连接。通常在低频段采用的数字波束成形,由于每根天线配置一条射频链路,功耗和成本较高。采用相阵架构实现射频波束成形是一种折衷的选择。本文研究了毫米波信道下移相器有限的量化精度在平面相阵单流波束控制(beam steering)中带来的性能损失。首先推导了阵列增益损失与移相器误差方差之间的理论关系,然后通过蒙特卡洛仿真验证该理论结果。从仿真结果可以看出平面相阵的增益损失可以通过增加移相器精度来减小。在通常应用中,4比特移相器在实现平面相阵波束控制时提供了足够的增益。

In the millimeter-wave band, due to the large path loss, beamforming is usually used to increase the link gain to establish a stable connection. Digital beamforming, which is typically used in the low frequency band, is a power consump- tive and costly solution due to the configuration of one RF link per antenna. Using phased array architecture to achieve RF beamforming is a compromise choice. In this paper, we study the beam steering performance loss of finite quantization precision phase shifter in millimeter wave channel. The theoretical relationship between the array gain loss and the error variance of the phase shifter is deduced first, and the results are verified by Monte Carlo simulation. It can be seen from the simulation that the gain loss of the phase array can be reduced by increasing the phase shifter accuracy. In a typical application, a 4-bit phase shifter provides sufficient gain to achieve planar array beam steering.