Title :
Quasi-optical 150-GHz power combining oscillator
Author :
Judaschke, Rolf ; Höft, Michael ; Schünemann, Klaus
Author_Institution :
Tech. Univ. Hamburg-Harburg, Hamburg, Germany
fDate :
5/1/2005 12:00:00 AM
Abstract :
A quasi-optical power combiner for a five-element in-line oscillator array is experimentally investigated at 150 GHz. The combiner consists of a periodic dielectric phase grating (hologram) which transforms the near-field of a rectangular horn antenna array into a pseudo-plane wave. The horn array is excited by IMPATT oscillators operating uniformly in both amplitude and phase. A dual offset reflector set-up transforms the pseudo-plane wave to a Gaussian beam which matches the field pattern of a dual mode receiving antenna. Even though an inter-element spacing of 9.5 λ has been chosen, the passive structure gives a power combining efficiency of 74.1%. The power combining oscillator has been operated in both free-running and injection-locked mode. A CW output power of 78.0 mW and 83.5 mW was measured for the free-running and injection-locked oscillator, respectively, which is corresponding to a power combining efficiency of 66.5% and 71.2%, respectively.
Keywords :
IMPATT oscillators; antenna radiation patterns; horn antennas; injection locked oscillators; microwave holography; millimetre wave oscillators; offset reflector antennas; power combiners; waveguide antenna arrays; 150 GHz; 78.0 mW; 83.5 mW; CW output power; Gaussian beam; IMPATT oscillators; dual mode receiving antenna; dual offset reflector; free-running mode; holography; in-line oscillator array; injection-locked mode; periodic dielectric phase grating; power combiner; pseudo-plane wave; quasioptical power combining oscillator; rectangular horn antenna array; Antenna arrays; Dielectrics; Gratings; Horn antennas; Injection-locked oscillators; Pattern matching; Phased arrays; Power combiners; Receiving antennas; Reflector antennas; Dual offset reflector; holography; in-line oscillator array; phase grating; quasi-optical oscillator; spatial power combining;
Journal_Title :
Microwave and Wireless Components Letters, IEEE
DOI :
10.1109/LMWC.2005.847660