Title :
Wide-band balanced active HEMT mixer
Author :
Yanev, Andrey S. ; Todorov, Bogdan N. ; Ranev, Vancety Z.
Author_Institution :
Inst. of Electron., Bulgarian Acad. of Sci., Sofia, Bulgaria
fDate :
7/1/2001 12:00:00 AM
Abstract :
The design and characteristics of a balanced active high electron-mobility transistor (HEMT) mixer operating in the 4.5-10-GHz frequency band are described in this paper. It consists of two parts implemented as independent hybrid circuits, namely, an microwave part fabricated by using a uniplanar technology and comprising a 180° hybrid ring coupler, HEMTs, and input-output matching circuits, and a low-frequency part consisting of an L-C balun and a low-pass filter built of discrete elements. The design of the microwave part of the mixer ensures a high degree of isolation between the signal and local-oscillator (LO) inputs within a wide frequency band at low IF. The measurements show a conversion gain of 5-7 dB, noise figure of 5-7.5 dB, and isolation between the signal and LO ports greater than 20 dB within the 4.5-10-GHz range
Keywords :
HEMT circuits; baluns; microwave mixers; waveguide couplers; 4.5 to 10 GHz; 5 to 7 dB; 5 to 7.5 dB; LC balun; RF-LO isolation; conversion gain; hybrid ring coupler; input-output matching circuit; low-pass filter; microwave circuit; noise figure; uniplanar technology; wideband balanced active HEMT mixer; Coupling circuits; Frequency; HEMTs; Impedance matching; Isolation technology; Low pass filters; MODFETs; Microwave circuits; Microwave technology; Wideband;
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
