Chisel-edged screens to reduce loss in highly overmoded THz iris lines with finite screen thickness

TL;DR

This paper investigates how finite screen thickness affects power losses in overmoded THz iris-line waveguides and proposes a geometric variation to minimize ohmic loss growth, improving waveguide efficiency.

Contribution

It provides a detailed theoretical analysis of power loss trends related to screen thickness and introduces a geometric variation to reduce ohmic losses in practical waveguides.

Findings

Diffraction and ohmic power losses increase with screen thickness.

Eigen and transient analyses help predict loss behaviors.

A geometric variation limits ohmic loss growth in thicker screens.

Abstract

In this note we report observations on the growth trends of diffraction power loss and ohmic power loss, as functions of screen thickness, in highly overmoded THz iris-line waveguides that are constructed from thin screens. Recent theoretical developments have given a detailed field description, including eigen and transient analyses, that characterizes such waveguides under paraxial dipole-mode excitation. Informed by these analyses, we can better estimate -- and minimize -- power loss effects due to finite screen thickness in practical realizations. A geometric variation is proposed whereby we limit the growth trend in ohmic loss, even when using relatively thicker screens in practice.