35-65GHz MMIC QPSK Modulator

A novel method for directly producing QPSK modulation from baseband IQ signals is presented. The key feature of the architecture is the absence of mixers and as a result unwanted mixing products. A broadband MMIC modulator chip is demonstrated at V band to showcase the performance of the modulator. It completely covers the world wide frequency band allocation for the forthcoming 60 GHz indoor wireless communication system. The power consumption of the circuit is less than 50 mW and its 1 dB compression point is 17 dBm. The overall insertion loss of the circuit is 9.5plusmn2 dB over the frequency band 35-65 GHz with phase state errors below plusmn15 deg. Up to 2 Gbps bit rate signaling rates should be achievable using the circuit.