Simple microwave QPSK modulator using piezoelectric transducers

A new technique to realise a simple low-cost binary-phase-shift-keying (BPSK) or quadri-phase-shift-keying (QPSK) modulator using a piezoelectric transducer (PET) is described. This modulator has the advantages of low loss, high power handling capability, low power consumption, and simple structure. The technique can be applied to any microwave and millimetre-wave frequency.