A 1 W Si-LDMOS power amplifier with 40 % drain efficiency for 6 GHz WLAN applications

The design and characterization of LDMOS power transistors and amplifiers developed for 6 GHz WLAN applications are presented. Transistors of different size were fabricated in a 0.25 μm SiGe:C BiCMOS technology and have been characterized using a load/source pull measurement system. Based on this characterization a 5.8-5.9 GHz power amplifier was designed, fabricated and tested. By using on-board Wilkinson combiner structures an output power of 1 W at 1 dB power compression was achieved. The measured maximum drain efficiency/PAE were 40/28 % with a small signal gain of 7.2 dB. From the modulated signal evaluation using a 802.11p test signal an ACPR of -38 dBc and an error vector magnitude of 3 % were determined at 1 dB peak power compression.