Software-defined radio (SDR) can support multiple communication standards and provide flexible services. In this paper, a feasible radio frequency (RF) bandpass sampling architecture of single-channel SDR receiver is proposed. The tradeoff between the sampling frequency and resolution of the analog-to-digital converter (ADC) and the selectivity and tunability of the bandpass filter provides a natural way to alleviate the design challenge of RF bandpass filter. The passband of the bandpass filter can be wider than the bandwidth of the desired signal, resulting in increasing the sampling frequency and resolution. The minimum acceptable sampling frequency is based on the bandwidth of the signal and the passband of the bandpass filter. The out-of-band interferences are further attenuated in digital domain. The signal can be decimated by sample rate conversion after it has been converted to baseband to reduce the processing rate.