Title :
A balanced 11 GHz HEMT up-converter
Author :
Bura, P. ; Vassilakis, B.
Author_Institution :
Northern Telecom, Montreal, Que., Canada
Abstract :
A 70-MHz-11-GHz balanced up-converter circuit is described. HEMTs (high electron mobility transistors) were found to be very suitable for this application due to their high gain at 11 GHz. The measured results show 7-dBm, 1-dB gain compression point, 15-dBm third-order intercept point, 3-dB conversion gain, and 35-dB LO (local oscillator) suppression. In a linearized mode the up-converter exhibited IMR (intermodulation ratio) of better than -40 dBc up to 0 dBm single-tone output level. A diode up-converter IMR of -40 dBc typically has at -6 dBm output level (single tone). The HEMT up-converter operates with the same linearity at a 6-dB-higher level as the diode up-converter for the same LO drive. The higher linear output level is important for digital QAM (quadrature amplitude modulation) radio applications, as the gain of the transmitter power amplifier can be correspondingly reduced.<>
Keywords :
frequency convertors; high electron mobility transistors; solid-state microwave circuits; 70 to 11 GHz; HEMT up-converter; SHF; balanced upconvertor; digital QAM; high electron mobility transistors; linearized mode; microwave circuits; quadrature amplitude modulation; radio applications; Circuits; Diodes; Gain measurement; HEMTs; High power amplifiers; Linearity; Local oscillators; MODFETs; Quadrature amplitude modulation; Radio transmitters;
Conference_Titel :
Microwave Symposium Digest, 1989., IEEE MTT-S International
Conference_Location :
Long Beach, CA, USA
DOI :
10.1109/MWSYM.1989.38965
