The influence of the air gap on the characteristics of the double-shielded microstrip delay devices

Abstract

A double-shielded microstrip (DSM) device is made of conventional microstrip device and by mounting additional shielded dielectric plate on top of it. The resulting structure is similar to the strip line, but there is a significant difference – a thin air gap that is equal to the thickness of the microstrip. The thickness of this air gap can become uncontrollable in the device manufacture process. In this paper the influence of thin air gap on the electrical parameters of DSM devices such as: microstrip line, coupled lines, multiconductor line, and meander delay line is investigated.