2022/07/25 by Jiayang Yu, Jixin Chen, Peigen Zhou +8 · 2 citations
Engineering · #Radio Frequency Integrated Circuit Design #Microwave Engineering and Waveguides #Advanced Power Amplifier Design
paper · doi:10.1109/jssc.2022.3192043
This article presents a broadband sub-terahertz (THz) power amplifier (PA) with a low-loss four-way power combiner. The proposed power combiner consists of an improved zero-degree combiner (ZDC) and a three-conductor Marchand balun simultaneously achieving broadband matching and power combining. The proposed three-conductor Marchand balun adopts a dual- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">LC </tex-math></inline-formula> tank technique by merging two resonators, and it can be equivalent to a transformer-based multi-resonating network. The power distribution is realized by one input power splitter generating two pairs of differential signals and two parallel 1-to-2 active power splitters. This hybrid distribution driving network further enhances efficiency and power gain. Based on these improvements, a high-output-power sub-THz PA with superior efficiency has been fabricated in the 130-nm SiGe bipolar complementary metal oxide silicon field effect transistor (BiCMOS) technology. The three-stage PA achieves a peak power gain of 16.4 dB, 3-dB small-signal gain bandwidth of 52 GHz from 211 to 263 GHz, a measured maximum saturated output power of 14.7 dBm at 224 GHz, and a peak power-added efficiency (PAE) of 3.13% at 220 GHz. The folded input splitter and extremely compact power combining methodology lead to a core area of 770 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">μ m × 280 μ m </tex-math></inline-formula> .