Study of a simple method for dielectric constant characterization of microwave substrates
Date of Issue2017-05-29
School of Electrical and Electronic Engineering
The impact of dielectric constant on radiation efficiency of embedded antenna is investigated both analytically and numerically. An antenna working in a dissipative medium such as human body or other liquid environments needs to be insulated to avoid short circuit, oxidation and corrosion caused by surrounding medium, which lead to the use of a dielectric medium that encloses the antenna. However, the question is how to make sure the selected materials able to meet the requirement of encloses the antenna. It is very important to measure the accurate dielectric constant when selecting the materials. Generally Speaking, resonant structure could be used for very accurate measurement at certain frequency instead of a range of wide frequency  .The configuration of the resonant structures also much simpler than the free space method. In this letter, a circular cavity structure with wide range of resonant frequencies is presented. The measurement of complex permittivity also conducted within the frequency range of 4GHz-6GHz. With reference of the resonant frequencies and bandwidth at resonant points, we are able to determine the complex permittivity accurately.
Final Year Project (FYP)
Nanyang Technological University