Q Band Solid-State Power Amplifier for Aerospace

This paper presents the methodology and key techniques of a Q band 20 watts solid-state power amplifier (SSPA). The high efficiency four-ways low loss power combination techniques based on magic T is developed to achieve high output power. Copper diamond and heat pipes were applied to overcome heat dissipation and thermal flux challenges. The proposed PA is then fabricated and measured. The output power is at the range of 42.9dBm to 44.8dBm with the efficiency of 7% to 10.5%, at the frequency range from 37GHz to 42.5GHz. Within 2GHz bandwidth from 38.5GHz to 40.5GHz, the output power is higher than 44dBm with the efficiency higher than 10%. The peak output power is nearly 44.3dBm, with the corresponding efficiency of 10.5^%. All the measured results include power supply efficiency and the output isolator loss.