Flicker noise removal in microwave oscillators using GaAs based feedforward amplifiers

Author

Everard, J.K.A. ; Broomfield, C.

Author_Institution

Dept. of Electron., York Univ., UK

fYear

2001

fDate

6/23/1905 12:00:00 AM

Firstpage

156

Lastpage

161

Abstract

Transposed flicker noise removal is demonstrated in a 7.6 GHz microwave oscillator for offsets greater than 10 kHz. This is achieved by using a GaAs based feedforward power amplifier as the oscillation sustaining stage. 20 dB noise suppression is demonstrated at 12.5 kHz offset when the error correcting amplifier is switched on. The phase noise rolls-off at (1/Δf)² for offsets greater than 10 kHz and is therefore set by the thermal noise to within 0-2 dB of the theoretical minimum. Preliminary results on some low frequency detection and low frequency feedback circuits are presented

Keywords

circuit noise; feedforward; flicker noise; gallium arsenide; interference suppression; microwave oscillators; phase noise; power amplifiers; thermal noise; 1 to 30 kHz; 7.6 GHz; GaAs; GaAs based feedforward amplifier; error correcting amplifier; feedforward power amplifier; flicker noise removal; low frequency detection circuits; low frequency feedback circuits; low phase noise oscillator; microwave oscillator; oscillation sustaining stage; phase noise reduction; thermal noise; 1f noise; Circuit noise; Error correction; Feedback circuits; Frequency; Gallium arsenide; Low-frequency noise; Microwave oscillators; Phase noise; Power amplifiers;

fLanguage

English

Publisher

ieee

Conference_Titel

Frequency Control Symposium and PDA Exhibition, 2001. Proceedings of the 2001 IEEE International

Conference_Location

Seattle, WA

ISSN

1075-6787

Print_ISBN

0-7803-7028-7

Type

conf

DOI

10.1109/FREQ.2001.956180

Filename

956180