Highly Integrated, Very High Gain 20Watt X-Band SSPA in GaN Technology

Abstract

This paper shows design and development of a highly integrated solid state power amplifier (SSPA) operating in X-Band. The last amplifying stage is realized in GaN technology. For the first time in the high power amplifier, the vertical orientation of the last amplification stage was used, which allowed to significantly minimize the footprint of the device while maintaining high output power and PAE. The device includes full digital control over the entire RF chain using a custom BIAS ASIC controlled via SPI interface, assuring high flexibility and stability of the SSPA. The SSPA operates in a wide frequency range of 8.025 - 8.4 GHz with 20 Watt output power at input power range of -20 dBm to 0 dBm and power added efficiency (PAE) reaching up to 35 %. Although the main application of presented SSPA is earth observation (EO) it can be used in ground segment, e.g. for radar application as well.