4.5-/4.9-GHz-Band Selective High-Efficiency GaN HEMT Power Amplifier by Characteristic Impedance Switching

Kazuki MASHIMO  Ryo ISHIKAWA  Kazuhiko HONJO  

IEICE TRANSACTIONS on Electronics   Vol.E101-C   No.10   pp.751-758
Publication Date: 2018/10/01
Online ISSN: 1745-1353
DOI: 10.1587/transele.E101.C.751
Type of Manuscript: Special Section PAPER (Special Section on Microwave and Millimeter-Wave Technologies)
power amplifier,  high efficiency,  band selective,  GaN HEMT,  PIN diode,  

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A 4.5-/4.9-GHz band-selective GaN HEMT high-efficiency power amplifier has been designed and evaluated for next-generation wireless communication systems. An optimum termination impedance for each high-efficiency operation band was changed by using PIN diodes inserted into a harmonic treatment circuit at the output side. In order to minimize the influence of the insertion loss of the PIN diodes, an additional line is arranged in parallel with the open-ended stub used for second harmonic treatment, and the line and stub are connected with the PIN diodes to change the effective characteristic impedance. The fabricated GaN HEMT amplifier achieved a maximum power-added efficiency of 57% and 66% and a maximum drain efficiency of 62% and 70% at 4.6 and 5.0GHz, respectively, with a saturated output power of 38dBm, for each switched condition.