A multi band flexible N-path filter suited for non-contiguous channel aggregation

This paper presents a novel approach to build multiband filters using N-path architecture. The proposed technique is based on using several bandpass N-path filters in parallel all centred at the same frequency but with different bandwidths. The signal reconstruction is achieved by subtracting/summing the different channels. The proposed solution offers several advantages. First as all the N-path networks are clocked using the same frequency, the constraints on the clock generation are kept low. Second, the solution offers high flexibility as it is based on N-path filters which can be easily reconfigured using their sampling frequency. Third, thanks to its multi-path architecture, it overcomes the switch ON resistance induced limitation of out-of-band attenuation thereby allowing to use smaller switches.