Microwave Solid State Broadband Amplifier

As rapid development of communication technology, the need of transmitting module in wireless communication system has been increased. In result, the specifications of transmitting module are improved. And solid device is among power amplifiers. Immense amounts of concrete research on new type of power devices made from GaN material, which has the features: high drain-source or grid-source breakdown voltage, good frequency characteristic, low noise coefficient, large current density, etc. So, these power amplifiers will be popular with designers. This paper is focused on GaN transistor power amplifier. Applying its large signal model, author simulates its input and output resistance together with load-pull. After matching the resistance, good characteristic of GaN amplifier is verified.First, author introduces the development of amplifiers made of semiconductor martial and the need of power amplifier in wireless communication. Some key specifications of it and their effect on wireless communication are discussed. And main work have been done is demonstrated.Second, comparison has been made among some several generations of semiconductor material. Author pays attention to GaN HEMT material and its physical characteristics. Principle analysis is made.Third, Theory of microwave power amplifier is introduced. And procedure of designing a amplifier, fundamental knowledge of transistor, S-parameter model, design of bias circuit, stability analysis, signal model and resistance match are also introduced to show a clear picture of power amplifier design.Fourth, the design of a microwave broadband solid power amplifier is made. Author demonstrates how to match input and output resistance of power amplifier applying large signal model and to calculate input and output resistance together with load-pull in details.At last, a required microwave broadband solid power amplifier is set up successfully. Test data and real product photo are shown to verify its performance. And some experience is shared for other designs.Some parameters are:Bandwidth: 1~2 GHz;Gain: ?15dB;Flatness: ±2dB;Standing wave ratio: ?2;Output power: ?36dBm...