Low-Cost CMOS Active Array Solution for Highly Dense X-Band Weather Radar Network

This article presents the development of a CMOS active array antenna unit cell as a potential solution for a highly dense, low-altitude short-coverage phased array X-band radar network system. The antenna uses a cross-patch differential feed structure designed in a stacked configuration for bandwidth and cross-polarization enhancement. To overcome the limitations of current CMOS RF performance, a mirroring technique was applied at the element and subarray level. A 16-element array (4x4 elements), integrated with CMOS T/R modules in a tileable architecture, was developed and characterized. Measured results demonstrate that this proposed array offers cross-polarization levels less than -32 dB across the scanning range of +/- 45 degrees in the principal planes for dual-polarized alternate transmit and alternate receive (ATAR) phased array weather radar.