Design of a K-Band Power Amplifier Using On-Wafer-Tuning Load-Pull Method

Minoru IDA  Masashi NAKATSUGAWA  

Publication
IEICE TRANSACTIONS on Electronics   Vol.E81-C   No.6   pp.882-885
Publication Date: 1998/06/25
Online ISSN: 
DOI: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Microwave and Millimeter-Wave Module Technology)
Category: Semiconductor Devices and Amplifiers
Keyword: 
power amplifier,  load-pull measurement,  on-wafer,  MMIC,  HEMT,  

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Summary: 
In high-frequency operation, it is difficult to obtain a large tuning range in load-pull measurement due to losses in the tuning network and RF-probes. In this paper, a low-loss on-wafer-tuning load-pull method is proposed. The output matching network consists of two CPWs connected to a FET output terminal. The impedance of the network can be controlled by changing the effective length of the CPWs by replacing RF-probes and removing air-bridges. To confirm the validity of this load-pull method, a K-band high-efficiency MMIC power amplifier has been designed using the method and fabricated. The amplifier demonstrates performance of 19. 5-dBm saturated output power, 12. 5-dB linear gain and 49. 3% maximum power-added efficiency (PAE) at Vds = 3 V for 26 GHz operation. At 1-dB gain-compression, the PAE is still as high as 44%. This high PAE result clearly indicates that the proposed method is a useful tool for designing power amplifiers, especially those for use in high-frequency (e.g. K-band) operation.