In this paper consideration is given to the design of bandwidth (and frequency) reconfigurable input multiplexers. Different channel filter architectures are discussed and important RF parameters including spectral efficiency and cochannel interference are considered. It is shown that large bandwidth adjustability could be possible when two tuneable bandpass filters per channel are cascaded. Experimental results of a simple experimental reconfigurable multiplexer are presented to evaluate the RF trade-offs and address the tuning mechanism.