A New Class of Low-Loss High-Linearity Electronically Reconfigurable Microwave Filter

A novel electronically reconfigurable microwave
bandpass filter based on a switched delay-line approach is presented.
In contrast to conventional tunable filters, the approach
enables the lossy and nonlinear switching elements to be used as
part of the coupling elements rather than within the resonators.
Therefore, the filter distinguishes itself through its ability to
provide a wide tuning bandwidth with low passband loss and high
linearity. Theoretical analysis of the approach is presented in this
paper. The feasibility of the approach has been experimentally
verified with microstrip circuit prototypes. The filter produced
a maximum passband loss of 1.7 dB and a third-order intercept
point of 32 dBm with 35% tuning bandwidth.