Antialiasing method for image aliasing in bandpass-sampling-based receiver

It is well known that image aliasing limits the flexibility of bandpass sampling receivers. In this context, a method that utilizes a second-order bandpass sampling structure with a tunable delay to eliminate image aliasing via digital signals is proposed. The antialiasing filter in the proposed method incorporates a simplified gains model/algorithm in which image aliasing is suppressed by adjustment of the complex gain in accordance with the location/position of the RF signal in the frequency domain. The proposed algorithm is easier to implement and can realize unaliased reception regardless of the location of the RF signal. Simulation results demonstrate that bandpass signals at arbitrary positions around 0.5–6 GHz can be received through the same receiver, and image aliasing is suppressed by almost 30 dB. Thus, the proposed method improves the extensibility of the receiver.