An Automated Amplitudes-Only Measurement System for Permittivity Determination using Free-Space Method


An automated PC based free-space system for determining the permittivity of high-loss materials is proposed. The main feature of the system is to measure only the amplitudes of transmission and reflection coefficients using free-space method and determine the permittivity dynamically using a computer. Firstly, the expressions for the reflection and transmission coefficients involving the permittivity of the high-loss material are derived. Then these equations are solved together by using the halving method. In order to measure the amplitudes of reflection and transmission coefficients, a simple and inexpensive microwave measurement system is established. The parallel port is used as an interface between the computer and the designed control circuit. A software program is developed for the treatment of the measured signal amplitudes and determination the permittivity of high-loss materials.

Meeting Name

18th IEEE Instrumentation and Measurement Technology Conference, 2001. IMTC 2001


Electrical and Computer Engineering

Keywords and Phrases

PC Based Free-Space System; Automated Amplitudes-Only Measurement System; Computerised Instrumentation; Control Circuit; Electrical Engineering Computing; High-Loss Materials; Microwave Measurement; Microwave Measurement System; Parallel Port Interface; Permittivity Determination; Permittivity Measurement; Physics Computing; Ray Tracing; Reflection Coefficients; Software Program; Transmission Coefficient

Document Type

Article - Conference proceedings

Document Version


File Type





© 2001 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Jan 2001