Title :
Low-noise Ku-band MMIC balanced P-HEMT upconverter
Author :
De la Fuente, Ma L. ; Portilla, J. ; Pascual, J.P. ; Artal, E.
Author_Institution :
Dept. de Ingenieria de Comunicaciones, Cantabria Univ., Santander, Spain
fDate :
2/1/1999 12:00:00 AM
Abstract :
An enhanced design methodology for a low-noise Ku-band monolithic balanced high electron mobility transistor (HEMT) upconverter and its performance are presented in this paper. The mixer topology consists of a common source/common gate HEMT pair that performs the mixing and balun functions. A detailed study has been done to establish the role of the transistor model elements in the performance of the mixer. Based on this study, a new analysis is proposed to optimize the operating point of the mixer in order to get a tradeoff between conversion gain and port isolations. To combine the LO and intermediate-frequency (IF) signals, active circuits were used, as well as a high-pass filter in order to improve the isolations. The circuit size, including the filter and the combiners, is 3 mm2. On-wafer measurements show a conversion gain over 2.5 dB, with only 3 dBm of LO power. A LO/RF isolation over 27 dB was measured in the whole LO band. The LO/IF isolation is over 27 dB thanks to the low reverse gain of the combiner HEMT´s. A single sideband noise figure of 7.3 dB has been obtained
Keywords :
HEMT integrated circuits; MMIC frequency convertors; MMIC mixers; field effect MMIC; integrated circuit design; integrated circuit noise; nonlinear network synthesis; 2.5 dB; 7.3 dB; Ku-band; LO/IF signals combining; MMIC balanced PHEMT upconverter; SHF; active circuits; balun function; common source/common gate HEMT pair; conversion gain; design methodology; high electron mobility transistor; high-pass filter; low-noise upconverter; mixer operating point optimisation; mixer topology; port isolations; pseudomorphic HEMT; transistor model elements; Active circuits; Design methodology; Filters; Gain measurement; HEMTs; Impedance matching; MMICs; MODFETs; Power measurement; Topology;
Journal_Title :
Solid-State Circuits, IEEE Journal of
