Gap waveguides for millimeter wave slow wave structures

Abstract

The use of groove gap waveguide technology is proposed to aid the design of wide band slow wave structures for millimeter wave travelling wave tubes. The possibility to control the electromagnetic wave without the need for metal contact at the walls can facilitate the realization at high frequencies while increasing design flexibility.

Parametric Study of Pin-based Gap Waveguide for Millimeter Wave Slow Wave Structures

“…Recently, it has been shown that electromagnetic bandgap (EBG) periodic structures can replace the metal walls of the rectangular corrugated waveguides to aid the design of sheet beam SWSs, [3], [4]. The main advantages of electromagnetic bandgap-based SWS are the inherent filtering capabilities of these structures which can be designed to support only the desired electromagnetic mode and the possibility to alleviate some of the assembly issues of conventional waveguides.…”

“…Gap waveguides are based on periodic textured surfaces which mimic the EBG properties, acting as a high impedance surface, placed parallel to a metal conductor with a gap of less than a quarter of the desired wavelength. An example of pin-based groove gap waveguide SWS is reported in [3] and [7]. Dimensions of the pins and gap with the top metal plate affect the design of the electromagnetic bandstop of this periodic structure and the dispersion of the slow wave structure mode.…”