Radio-Frequency Characteristics of a Printed Rectangular Helix Slow-Wave Structure

Abstract

A new type of printed rectangular helix slow-wave structure (SWS) is investigated using the field-matching method and the electromagnetic integral equations at the boundaries. The radio-frequency characteristics including the dispersion equation and the coupling impedance for transverse antisymmetric (odd) modes of this structure are analysed. The numerical results agree well with the results obtained by the EM simulation software HFSS. It is shown that the dispersion of the rectangular helix circuit is weakened, the phase velocity is reduced after filling the dielectric materials in the rectangular helix SWS. As a planar slow-wave structure, this structure has potential applications in compact TWTs.

Dispersion Analysis of a Planar Rectangular Tape Helix Slow Wave Structures Supported by Dielectric Rods

“…The field analysis of a rectangular unloaded planar SWS considering only one-quarter of the structure to satisfy the boundary conditions and dividing the crosssectional geometry into four regions was proposed by Fu et al in [15]. A similar field analysis approach was extended to the dielectric loaded planar TWT structure by Fu et al in [16], where the area between the planar rectangular helix and the outer enclosing conductor is filled with dielectric material with the assumption that the permittivity of the discrete dielectric rods, ϵ r is averaged to obtain the effective permittivity ϵ eff .…”

Investigation into a triangular-helix slow-wave structure

“…Present push towards higher RF efficiency and compact size has brought in several innovations in the construction of helix SWS, like, square / rectangular helix, planar micro-fabricated helix, etc [1]- [5]. The need towards high efficiency has led the present authors to conceptualize a triangular-helix equivalent of a circular helix that shows the promise of higher interaction impedance compared to a conventional circular helix.…”

Effect of Structural Parameters on High Frequency Characteristics of Microstrip Meander-Line Slow Wave Circuit

“…Fortunately, the advanced micro-fabrication technology can provide a rather easy and fast way for 3-D micro-structure, which results in innovation of microwave minicomponents [2]. Thus, the microstrip meander-line SWS as a new plane-type structure has drawn more and more attentions [3]. This kind of structure is a plane slow-wave circuit with a single metal microstrip periodic array on a dielectric substrate, which is made conveniently by micro-fabrication technology.…”