Enclosure Effect on Microwave Power Amplifier

The package design for microwave sub-systems requires adequate knowledge of electromagnetic field distribution inside the package housing. The cavity resonance of the microwave amplifier not only degrades the electrical performance, the feedback through the resonance mode also can cause unwanted oscillation in the frequency band of interest. It may even result in catastrophic failure of the device, wherein the peak oscillating voltage exceeds the device breakdown voltage. Hence, comprehensive analysis of the package effects is one of the prime requirements for stable microwave amplifier design for high-rel applications. This paper describes modeling, analysis of the package and different mitigation techniques to make stable, resonance free microwave amplifier for a C-band spaceborne SAR payload.