Controllable Waveguide Based on Capacitively Loaded Wire Medium

In this presentation we discuss dispersion, losses and excitation of metal waveguides, filled with wire media, loaded by tunable capacitances. Standard rectangular and square cross section waveguides are considered. The waveguides can be filled with usual (single) and crossed (double) wire media (WM). In the standard waveguides, filled with the single WM, capacitances, inserted near wide walls, create pass bands located much lower than the cutoff frequency. For example, in the waveguide, having the cutoff frequency 26 GHz, we have found propagating modes in the frequency range 5-10 GHz. Dispersion of modes in these pass bands is very sensitive to a change of capacitances. Such loaded waveguides can form a new class of controllable microwave devices. Tunability of modes, propagating below the cutoff of the empty waveguide, is studied numerically and experimentally.