Title :
Reduced flicker noise in microwave oscillators using feedforward amplifiers
Author :
Everard, J.K.A. ; Broomfield, C.
Author_Institution :
Dept. of Electron., York Univ., UK
Abstract :
Transposed flicker noise removal is demonstrated in a 7.6 GHz microwave oscillator for offsets greater that 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//spl Delta/F)/sup 2/ for offsets greater than 10 kHz and is therefore set by the thermal noise to within 0-2 dB of the theoretical minimum.
Keywords :
feedforward; flicker noise; microwave circuits; microwave oscillators; phase noise; thermal noise; 7.6 GHz; GaAs; error correcting amplifier; feedforward power amplifier; flicker noise; microwave oscillators; noise suppression; oscillation sustaining stage; phase noise; thermal noise; 1f noise; Error correction; Gallium arsenide; Microwave amplifiers; Microwave frequencies; Microwave oscillators; Noise level; Phase noise; Power amplifiers; Silicon;
Conference_Titel :
Microwave Symposium Digest, 2001 IEEE MTT-S International
Conference_Location :
Phoenix, AZ, USA
Print_ISBN :
0-7803-6538-0
DOI :
10.1109/MWSYM.2001.967171
