Linear Microwave RF Amplifier vol.1

Design and build a prototype single stage Microwave power amplifier operated at 2.4 GHz with a linear region of operation up to our desired output of 1 watt or 30 dBm.

As a design team, we came to the conclusion that we wanted to design our amplifier to operate in the 2.4 GHz ISM (Industrial, Scientific, and Medical) Band. Typical 2.4 GHz Microwave amplifiers on the market were researched and comparable target specifications were proposed. The overall target specifications of the amplifier design are as follows:

·  Operating frequency @ 2.4GHz
·  Output power of 1 watt (30 dBm)
·  Obtain a gain of +10 ~12db
·  1dB compression >= 30dbm
·  Cost < $ 100

The applications of our proposed device include many products in the field of microwave communications. One of the important applications of a Microwave power amplifier is in the output stage of a transmitter where a signal needs amplification before it is transmitted. A high power amplifier is needed for transmitting a signal through an antenna and a medium. The Microwave power amplifier amplifies the input signal after the signal has been modulated in the transmitter. The High power amplification step is necessary for every application of antenna transmission.

A power amplifier is an amplifier that takes a low or intermediate level signal and significantly boosts its power level. At low frequencies this might be a trivial design which would only involve the careful choice of a DC bias circuit designed for maximum power output. But our chosen amplifier design is designed to operate at the microwave frequency of 2.4 GHz. When operating at this frequency, transmission line theory comes into the picture. The high frequency and short wavelength of microwave energy make for difficulties in analysis and design of microwave components and systems. Matching of the input and output of the transistor must be considered and designed around.