Design of Ultra-Wideband Power Amplifier Based on Extended Resistive Continuous Class B/J Mode

• Published in: IEEE transactions on circuits and systems. II, Express briefs Vol. 69; no. 2; pp. 419 - 423
• Main Authors: Latha, Y. Mary Asha, Rawat, Karun
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.02.2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Amplifier design; Bandwidth; Bandwidths; Commercialization; continuous class J; design space; Efficiency; GaN HEMT; Harmonic analysis; Impedance; Multi-octave; power amplifier (PA); Power amplifiers; Power generation; Transistors; Ultra wideband technology; ultra-wideband; Ultrawideband
• ISSN: 1549-7747; 1558-3791
• DOI: 10.1109/TCSII.2021.3095379

This brief presents the design of an ultra-wideband high-efficiency extended resistive continuous class B/J (ERCB/J) power amplifier (PA). Beyond an octave bandwidth, the conventional class B/J mode is inappropriate. Whereas the existing resistive-reactive class J modes present an overlapped impedance space at the expense of the efficiency and power degradation or voltage swing beyond 4 <inline-formula> <tex-math notation="LaTeX">V_{DD} </tex-math></inline-formula>. Therefore, this brief presents a novel ERCB/J mode to achieve overlapping impedance space promising high efficiency over a multi-octave bandwidth. A design scheme is presented to map loads of the proposed mode to frequencies in the targeted multi-octave band to design a feasible matching network. For the proof of concept, a PA has been designed based on ERCB/J using commercialized GaN HEMT. This PA operates from 0.5-3.25 GHz, exhibiting fractional bandwidth of 146.7%. The peak drain efficiency of 60-70.1% and peak output power of 39.1-41.75 dBm are obtained at saturation over the operating band. The PA has also been tested with a two-tone signal with 10 MHz spacing and a 10 MHz LTE signal.