Microwave amplifier design using modern tools

number: 
27
English
Degree: 
Author: 
Salah Sahib Abdul-Ameer
Supervisor: 
Dr. Fawzi M. Al-Naima
Dr. Amer A. Naoom
year: 
1994
Abstract:

The task of this dissertation is to design and build a front end amplifier at the microwave region (S-band) planned to be used in a communication satellite.Primary design requirements are low noise figure, narrow bandwidth, and to some extent a high gain. These requirements can not be achieved with a single stage amplifier, thus a multistage amplifier has to be considered. A three stage amplifier has been designed with noise figure = 2.9 dB , gain = 35dB, and bandwidth =190 MHz. However, due to shortage of microwave components, a single stage amplifier was constructed at 2075. MHz and its design specifications were verified by measurement, Scattering matrix representation of a two port was adopted for its practical preference at microwave frequencies. Two matching networks for the input and output were designed. The input matching is responsible for the low noise characteristics, while the output matching produces improved gain performance at the low noise design conditions. Microstrip lines were used as matching elements to overcome practical limitations of conventional lumped elements. Theoretical calculations and optimizations were performed using the professional software (Touchstone) specially organized for microwave applications. Measurements of the final amplifier were performed using the Automatic Network Analyzer (Hewlett- Packard 8510B). A comparison between theory and measurement indicates a successful design and implementation.