Title :
Optically frequency modulated GaAs MESFET oscillator
Author :
Loriou, B. ; Guena, J. ; Sautereau, J.F.
Author_Institution :
Centre National d´´Etudes des Télécommunications, Lannion, France
Abstract :
A GaAs MESFET X-band oscillator has been frequency modulated by an amplitude modulated optical signal injected on the active device. A modulation index of 0.5 corresponding to MSK modulation has been achieved at 2 Mbit/s without parasitic amplitude modulation. It is shown that the FM modulation index variation against frequency is directly related to the drain current response of the FET considered as a photodetector. This responsivity has been measured to decrease above 5 MHz, which limits the oscillator FM capability.
Keywords :
III-V semiconductors; Schottky gate field effect transistors; field effect transistor circuits; frequency modulation; gallium arsenide; microwave oscillators; solid-state microwave circuits; 0.5 modulation index; 2 Mbit per sec; 5 MHz responsivity; FM modulation index; GaAs MESFET X-band oscillator; HF responsivity; MSK modulation; microwave oscillator; minimum shift keying modulation; optically frequency modulated;
Journal_Title :
Electronics Letters
DOI :
10.1049/el:19810628
