A compact Ka-band MMIC voltage controlled oscillator: Comparison of MESFET and HEMT implementations

Author

Bosch, D. ; Gawronski, M. ; Swirhun, S. ; Geddes, J. ; Beyer, J. ; Cravens, R.

Author_Institution

Alliant Techsys., Minnetonka, MN, USA

fYear

1991

fDate

10-14 July 1991

Firstpage

827

Abstract

A novel, compact Ka-band MMIC (monolithic microwave integrated circuit) voltage controlled oscillator (VCO) has been designed, fabricated and tested. The VCO design is a ´ring´ configuration using two FETs with two isolated control terminals, which provides increased tuning bandwidth. This design uses an active feedback topology, resulting in greater device size for higher output power and circuit Q. This VCO was fabricated with both 0.25 mu m gate length MESFET and HEMT (high electron mobility transistor) processes designed to have similar RF equivalent circuits by engineering the device doping. The measured MESFET VCO demonstrated a tuning bandwidth of 740 MHz centered at 35 GHz and an output power of 8.3 dBm. The measured HEMT VCO tuning bandwidth is greater, but phase noise is worse than that of the MESFET implementation.<>

Keywords

MMIC; field effect integrated circuits; microwave oscillators; variable-frequency oscillators; 0.25 micron; 35 GHz; 740 MHz; HEMT VCO; Ka-band MMIC voltage controlled oscillator; MESFET VCO; RF equivalent circuits; VCO design; active feedback topology; circuit Q; gate length; isolated control terminals; output power; phase noise; ring configuration; tuning bandwidth; Bandwidth; Circuit optimization; Circuit testing; HEMTs; MESFETs; MMICs; Microwave devices; Power generation; Tuning; Voltage-controlled oscillators;

fLanguage

English

Publisher

ieee

Conference_Titel

Microwave Symposium Digest, 1991., IEEE MTT-S International

Conference_Location

Boston, MA, USA

ISSN

0149-645X

Print_ISBN

0-87942-591-1

Type

conf

DOI

10.1109/MWSYM.1991.147134

Filename

147134