Compact low-cost 1-Watt and 4-Watt quad flat non-leaded (QFN) packaged Ka-Band high power amplifiers

This paper presents the design and performance of two new quad flat non-leaded (QFN) packaged high power amplifiers operating at Ka-band. The packaged amplifiers are fully compatible with conventional SMD assembly processes which significantly reduce assembly cost and complexity. The QFNs themselves are standard off-the-shelf low-cost plastic air-cavity packages. Matching networks that were designed to compensate packaging and wire-bond related parasitics was presented. The 1-Watt 4 times 4 mm² QFN packaged amplifier demonstrates min. +30 dBm CW saturated output power with power added efficiency (PAE) of 26%, and min. +20 dB small signal gain from 28 to 31 GHz. The 4-watt 5 times 5 mm² QFN packaged amplifier exhibits min. +35 dBm CW saturated output power with at least 20 dB small signal gain from 28 to 31 GHz. Saturated output power of +36 dBm was achieved from 29 to 31 GHz with PAE of 23%. Thermal analysis of the channel temperatures was also presented. To authors´ knowledge, these amplifiers are the first Ka-band packaged amplifiers to produce 1-watt and 4-watt saturated output power using standard plastic QFNs with the smallest sizes.