Patent ID: 7236053
Filing Date: 2007-06-26
Classification: H03F

Abstract:
1. A switch mode power amplifier for higher frequency applications comprising: a) a transistor having a first terminal, a second terminal, and a control terminal and having internal capacitance between the first terminal and second terminal, b) a signal input terminal coupled to the control terminal, c) a power terminal conductively coupled to the second terminal, d) a ground terminal coupled to the first terminal, e) a resonant circuit coupling the second terminal to an output terminal, and f) a resistance coupling the output terminal to the ground terminal, whereby an input signal controls conduction of the transistor and the second terminal is coupled to ground when the transistor is conducting with current from a power source to the second terminal increasing, and when the transistor is turned off current from the power supply is steered into the internal capacitance of the transistor and causes voltage on the second terminal to rise to a maximum value and then decrease, the voltage at the second terminal being coupled to the output terminal through the resonant circuit, and wherein the transistor comprises a compound semiconductor field effect transistor with the first terminal being a source terminal and the second terminal being a drain terminal, the transistor comprising: a compound semiconductor substrate, a buffer layer formed on the substrate, a channel layer formed on the buffer layer, and a barrier layer formed on the channel.