A systematic approach for design of the IF and base-band of a low-IF GSM receiver

A system oriented approach for the back-end design of a low-IF GSM receiver is presented to demonstrate the feasibility of achieving intermediate frequency (IF) around 100 kHz, good image rejection, and low power consumption. The main idea is that the proper intermediate frequency must be chosen with special attention to the frequency mask of the GSM standard. For the sake of the image signal attenuation, a 3^rd order passive poly phase filter is employed with 29 dB image rejection. The design considerations related to the poly phase filter, including the choice of the order of the poly phase filter, the optimum pole placement, and the mismatch analyses, are simulated. The concept of the image attenuator filter is also investigated.