A 930MHz CMOS DC-offset-free direct-conversion 4-FSK receiver

Effort to fully integrate radio frequency and baseband circuitry for a narrow-band application is presented. The receiver which is described uses harmonic mixing and differential structures. It uses a low-pass filter whose output signals are processed by a on-chip demodulator. A modified version of the zero-intermediate frequency zero-crossing demodulator is used. Optimization is done for transistor sizes for input matching. The DC offset cancellation is performed by the peak detector