A novel structure distributed active transformer (DAT), which significantly reduces the coupling from the DAT to the feed line is demonstrated. A grounded guard line is implemented to isolate the feed line from the magnetic field of the DAT. The measured result of the DAT on a GaAs substrate shows a 10.5-dB reduction in the coupling. To reduce DAT loss, an… (More)
This paper demonstrated the first 2-stage, 2.8W, 1.8V, 1.9GHz fully-integrated DAT power amplifier with 50Ω input and output matching using 0.18µm CMOS transistors. It has a small-signal gain of 27dB. The amplifier provides 2.8W of power into a 50Ω load with a PAE of 50%.