Small and low-loss quadrature hybrid and T/R local signal selection switch for 60 GHz direct conversion transceivers

A quadrature hybrid and a T/R selection switch of a local distribution circuit with small size and low loss are demonstrated for 60 GHz direct conversion transceivers. By applying the one-crossover parallel-line transformer and zigzag-shape capacitor, the quadrature hybrid occupies only 0.038 mm² and the insertion losses is <; 1 dB in Ch. 1-4 (58.32-64.8 GHz). Also, using the series L/shunt L input matching network of the buffer amplifier, a small active transformer-line switch is realized, where the required length of the transmission line is 100 μm. The estimated insertion losses of <; 1.4 dB are achieved in Ch. 3-4.