Circuit requirements of a direct conversion paging receiver

摘要

Circuit requirements of a direct-conversion FLEX paging receivernwith the zero-crossing interpolation demodulator are derived by means ofnhigh-level simulation. Impacts of the limitations on noise andnnonlinearity characteristics of the radio frequency (RF) stage, thenin-phase and quadrature-phase mismatch, and the local oscillatornfrequency drift are analyzed relative to the degradation of the bitnerror rate. Official specifications on radio paging receivers arenintroduced to ensure the minimum performance. It is shown that an RFnfront-end with 25-dB gain, 5.3-dB noise figure, and 11-dBm second ordernintercept point makes the receiver qualified for the sensitivity,ndesensitization, and intermodulation requirements