A new beam-former using a multi-layered phase-shifter for 60 GHz WPAN applications

In the 60 GHz standards, the smart antenna system is mandatory requirement for solving the non-line of sight (NLOS) problem and supporting large capacity and point to multi-point connections. For the smart antenna system in millimeter wave communication, the switched beam-forming is useful for the implementation. In this paper, a new switched beam-former using stackable multi-layered phase-shifter for 60 GHz WPAN applications is presented. To verify the idea, the new 4times4 beam-former was designed with low temperature ceramic co-firing (LTCC) process. The beam-former is composed of 4-way spatial dividers redesigned for the strip-line configuration, a stacked multi-layered phase-shifter and the single-pole 4-throw (SP4T) switches. The results are that the input return loss of all input ports is under -20 dB, the insertion loss is between -1 dB ~ -2 dB except the switches and the via transition losses, the output power deviations are under -2 dB, the bandwidth is 12% at 60 GHz, and the steering angles are plusmn30deg, plusmn60deg with phase error under plusmn5deg. These results show that the proposed beam-former has unique solution for solving the problems existed in conventional beam-formers.