Millimeter-Wave HEMT Oscillators

Tamio SAITO  Yoji OHASHI  Yoshihiro KAWASAKI  Naofumi OKUBO  Yutaka MIMINO  

IEICE TRANSACTIONS on Electronics   Vol.E74-C   No.12   pp.4119-4123
Publication Date: 1991/12/25
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Millimeter-Wave/Heterojunction Devices)

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This paper describes millimeter-wave HEMT oscillators developed to operate at 50 GHz and above. To determine the feasibility of using HEMTs for millimeter-wave oscillators, we measured and compared the low-frequency noise characteristics of both HEMT and GaAs MESFET devices and found them to have nearly identical characteristics. We also estimated the S parameters of a HEMT biased at Vds-3V and Ids5 mA for an equivalent circuit study. The oscillators consisted of a microstrip line resonator, a matching circuit, and a bias circuit. The output power and oscillation efficiency for the 60-GHz HEMT oscillator was 2.6dBm and 9.5%, and 2.8dBm and 6.4% for the 50-GHz oscillator. The efficiencies of these HEMT oscillators are higher than that of GaAs MESFET oscillators at millimeter-wave frequencies.