An offset compensated baseband receive channel for IS-95

An analog baseband receive channel for the IS-95 digital cellular wireless standard was designed. The receive channel features a gain of 35dB and meets a tight offset specification by utilizing a continuous on-chip loop around the filter. Total filter area was minimised by implementing a singly terminated switched capacitor ladder filter. The measured integrated input referred noise is 152µVrms. The measured IIP3 is 18dBm¹. Fabricated on a 0.25µm RFCMOS process the receive channel occupies 1.4mm²and dissipates 18.75mW from a 2.4V supply typically.