Broadband continuous mode power amplifier with on‐board harmonic injection. Issue 9 (16th April 2019)

• Record Type: Journal Article
• Authors: Mary Asha Latha, Yericharla; Rawat, Karun; Helaoui, Mohamed; Ghannouchi, Fadhel M.
• Is Part Of: IET microwaves, antennas & propagation. Volume 13:Issue 9(2019)
• Page Start: 1402
• Page End: 1407
• Publication Date: 2019-04-16
• Subjects: high electron mobility transistors -- III‐V semiconductors -- wide band gap semiconductors -- wideband amplifiers -- frequency multipliers -- gallium compounds -- UHF power amplifiers; injected harmonic signal -- continuous class B/J mode -- current generator reference plane -- frequency doubler -- broadband continuous mode power amplifier -- on‐board harmonic injection -- active harmonic injection -- single radio frequency input -- gallium nitride high‐electron‐mobility transistor -- long‐term evolution -- adjacent channel power ratio -- digital predistortion -- power 10.0 W -- power 15.0 W -- frequency 900.0 MHz -- frequency 20.0 MHz -- frequency 1.0 GHz to 1.9 GHz -- efficiency 60.04 percent to 70.96 percent -- GaN; Microwaves -- Periodicals; Microwave antennas -- Periodicals; Antennas (Electronics) -- Periodicals; Radio wave propagation -- Periodicals; Microwave communication systems -- Periodicals; 621.381305
• DOI: 10.1049/iet-map.2018.5885
• Languages: English
• ISSNs: 1751-8725

Abstract

Abstract : This study presents the design of a broadband continuous mode power amplifier (PA) with an active harmonic injection (HI). Since the injected harmonic signal is generated on‐board using a frequency doubler, this design has a single radio frequency input. The generated second harmonic is injected at the drain terminal of a gallium nitride high‐electron‐mobility transistor used in designing continuous class B/J PA. A design space in terms of amplitude and phase of the injected harmonic signal is analysed to obtain the loads that operate the PA in the continuous class B/J mode at the current generator reference plane. The proposed design strategy is verified by designing a prototype with a frequency doubler and a PA using 10 and 15 W gallium nitride high‐electron‐mobility transistors, respectively. The measured drain efficiency of 60.04–70.96% and output power of 40.17–42.6 dBm is obtained from 1 to 1.9 GHz. This corresponds to a broadband operation of 900 MHz with 62% fractional bandwidth. The designed HI–PA is also tested with a 20 MHz long‐term evolution signal whose corresponding adjacent channel power ratio is better than −47.76 dBc in the overall band after applying digital predistortion.