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 4×4 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 −20dB, the insertion loss is between −1dB ∼ −2dB except the switches and the via transition losses, the output power deviations are under −2dB, the bandwidth is 12% at 60 GHz, and the steering angles are ±30°, ±60° with phase error under ±5°. These results show that the proposed beam-former has unique solution for solving the problems existed in conventional beam-formers.
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