Title :
A Novel 94-GHz MHMET-Based Diode Mixer Using a 3–dB Tandem Coupler
Author :
Lee, Mun-Kyo ; Lim, Byeong-Ok ; LEE, Sang-Jin ; Ko, Dong-Sik ; Moon, Sung-Woon ; An, Dan ; Kim, Yong-Hoh ; Kim, Sam-Dong ; Park, Hyun-Chang ; Rhee, Jin-Koo
Author_Institution :
Millimeter-Wave Innovation Technol. Res. Center, Dongguk Univ., Seoul
Abstract :
We report a high-performance 94-GHz monolithic millimeter-wave integrated-circuit diode mixer using metamorphic high-electron mobility transistor (MHEMT) diodes and a coplanar waveguide tandem coupler. A novel single-balanced structure of diode mixer is proposed in this paper, where a 3-dB tandem coupler with two sections of parallel-coupled line and air-bridge crossover structures are used for wide frequency operation. The fabricated mixer exhibits excellent local oscillator-radio-frequency (LO-RF) isolation, greater than 30 dB, in the 5-GHz bandwidth of 91-96 GHz. A good conversion loss of 7.4 dB is measured at 94 GHz. The proposed MHEMT-based diode mixer shows superior LO-RF isolation and conversion loss to those of the W-band mixers reported to date.
Keywords :
MMIC; coplanar waveguides; high electron mobility transistors; mixers (circuits); MHMET-based diode mixer; air-bridge crossover structure; coplanar waveguide tandem coupler; frequency 94 GHz; metamorphic high-electron mobility transistor; monolithic millimeter-wave integrated-circuit diode mixer; parallel-coupled line; Bandwidth; Coplanar waveguides; Diodes; Frequency; HEMTs; Loss measurement; MODFETs; Millimeter wave transistors; Mixers; mHEMTs; Coplanar waveguide (CPW); W-band; diode mixer; metamorphic high-electron mobility transistors (MHEMTs); monolithic microwave integrated circuit (MMIC); tandem coupler;
Journal_Title :
Microwave and Wireless Components Letters, IEEE
DOI :
10.1109/LMWC.2008.2002466
