30-66 GHz millimetre wave phase shift keying modulator: performance and analysis

An octave bandwidth millimetre wave gallium arsenide (GaAs) MMIC modulator is demonstrated, wherein a novel method for directly producing QPSK/OQPSK/BPSK modulation directly from baseband IQ signals is presented. A key feature of the architecture is the absence of mixers. Expressions detailing the overall modulator error vector magnitude (EVM) performance with regard to its constituent components are derived. The dc power consumption of the circuit is less than 50 mW, and its 1 dB compression point is above 7 dBm. Frequency operation is between 30 and 66 GHz, over which QPSK EVM is below 15 , BPSK EVM 3 and data rates of greater than 500 MB/s are possible.