Compensation of RF impairment in multi-band receiver based on RF sub-sampling

This paper is studied about multi-band receiver using sub-sampling and time division multiplexing (TDM) techniques. Software defined radio (SDR) has a goal that places the analog to digital converter (ADC) as near the antenna as possible. But current technique actually cannot process ADC about radio frequency (RF) band signals. So one method is being studied that samples RF band signals to intermediate frequency (IF) band. As one of the ways, sub-sampling technique can convert signals from RF band to IF band without oscillator. If sub-sampling technique is used, over 2 bands can convert signals from RF band to IF band. However, due to the filter performance in RF band, it is possible that interference is generated between signals that are converted to low frequency band. And the problem degrades performance. In this paper, we propose one method that uses TDM technique as a solution to avoid interference between signals. By processing TDM and sub-sampling at the same time, the method can get signals without large changes from the conventional structures.