Development of GaAs Gunn Diodes and Their Applications to Frequency Modulated Continuous Wave Radar

• Published in: Japanese Journal of Applied Physics 2010-11, Vol.49 (11), p.111202-111202-4
• Main Authors: Choi, Seok-Gyu, Han, Min, Baek, Yong-Hyun, Ko, Dong-Sik, Baek, Tae-Jong, Lee, Sang-Jin, Kim, Jin-Ho, Lee, Seong-Dae, Kim, Mi-Ra, Chae, Yeon-Sik, Kathalingam, Adaikalam, Rhee, Jin-Koo
• Format: Article
• Language: English
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/JJAP.49.111202

In this work, we have designed and fabricated the GaAs Gunn diodes for a 94 GHz waveguide voltage controlled oscillator (VCO) which is one of the important parts in a frequency modulated continuous wave (FMCW) radar application. For fabrication of the high power GaAs Gunn diodes, we adopted a graded gap injector which enhances the output power and conversion efficiency by effectively removing the dead-zone. We have measured RF characteristics of the fabricated GaAs Gunn diodes. The operating current, oscillation frequency, and output power of the fabricated GaAs Gunn diodes are presented as a function of the anode diameters. The operating current increases with anode diameters, whereas the oscillation frequency decreases. The higher oscillation frequency was obtained from 60 $\mu$m anode diameters of the fabricated Gunn GaAs diodes and higher power was obtained from 68 $\mu$m. Also, for application of the 94 GHz FMCW radar system, we have fabricated the 94 GHz waveguide VCO. From the fabricated GaAs Gunn diodes of anode diameter of 60 $\mu$m, we have obtained the improved VCO performance.