Compact and Highly Efficient Short-Range Radar for Advanced Driver Assistant Systems

A compact and highly efficient 24 GHz circularly polarized (CP) short range radar (SRR) module is proposed. The proposed SRR is configured by highly integrated right-hand CP (RHCP) transmit (Tx) and left-hand CP (LHCP) receive (Rx) antenna arrays and a single 4-Tx and 4-Rx CMOS radar IC. The Tx RHCP and Rx LHCP antenna elements are coplanarly and concentrically arranged to form a 2 × 2 configuration for each Tx and Rx. The concentric integration can effectively increase the area efficiency while maintaining a high Tx-to-Rx isolation due to the opposite CP. Further, the radar IC is fabricated with TSMC 65 nm process and directly mounted on the back of the complete module. Each Tx and Rx channels of the IC are connected to each Tx and Rx array elements through multilayered feed network and bonding wires. Then, the SRR is operated as one Tx with 1 × 4 array and four Rx with individual antennas. Lastly, the complete CP SRR module is successfully verified at 24 GHz with a detection range from 1 m to 20 m.