Wideband RC polyphase network for IEEE 802.11a quadrature signal generation

A wideband RC polyphase network for quadrature signal generation is presented. A new approach based on a feedback calibration mechanism that capacitors are tuned according to the mismatch in amplitude of quadrature signals is proposed. The architecture is applied in an IEEE 802.11a quadrature signal generation circuit with a centre frequency of 5.5 GHz and a bandwidth of 1.8 GHz. This circuit is implemented with 0.13 m CMOS technology consuming 0.2 0.26 mm die area without pads. The simulation result shows that quadrature signals have less than 2.4 amplitude error and less than 0.5 phase error with 5 R and C mismatches from 4.6 to 6.4 GHz.