Q-factor enhancement of open 2D resonators by placement of thin metallic rods near the aperture

Thin metallic rods or wires are often used for tuning slotted resonators and waveguides. A vast number of publications have appeared in the literature and some of the approaches are exemplified in references [1– 5]. In this paper we consider a perfectly electrically conducting two-dimensional slotted cylindrical cavity of arbitrary cross-section, and a thin metallic rod or wire aligned with the axis of the cavity, also of arbitrary cross-section. The structure is illuminated by an E-polarised time-harmonic electromagnetic plane wave, incident from some specified direction.