DESIGN CONSIDERATIONS FOR DIRECT-CONVERSION RECEIVERS

This paper describes the issues and tradeoffs in the design and monoli thic implementation of direct-conversion receivers and proposes circui t techniques that can alleviate the drawbacks of this architecture, Fo llowing a brief study of heterodyne and image-reject topologies, the d irect-conversion architecture is introduced and effects such as de off set, I/Q mismatch, even-order distortion, flicker noise, and oscillato r leakage are analyzed. Related design techniques for amplification an d mixing, quadrature phase calibration, and baseband processing are al so described.