Microwave Frequency Synthesizer Research Articles

The ohio state university compact radar cross-section measurement range

The ElectroScience Laboratory at The Ohio State University has recently installed a new radar cross-section measurement system. The system uses a Scientific Atlanta compact range reflector (an offset parabolic reflector) to generate a far-field plane wave in the confines of a 40 \times 20 \times 60 ft anechoic chamber. The system uses a computer controlled microwave frequency synthesizer and a multichannel computer controlled receiver. The target support/positioning system and an optical target alignment system are also interfaced to the computer. The parameters of the system are 1) operation from 1 to 30 GHz (eventual operation to 96 GHz has been confirmed by field probing); 2) a plane wave volume (test area volume) of 1.3 m diameter; and 3) a sensitivity of -50 dBsm. Of particular importance is the ability of the system to measure phase as well as amplitude. This permits vector subtraction of the background and system calibration using a reference (sphere) target. The development of this system and the performance characteristics obtained so far will be discussed. Some results which demonstrate the system performance will be shown. Of particular interest is the broad-band measurement of both amplitude and phase. This permits conversion of the results to the time domain. Examples will be shown in which the various system components (antennas, reflector, walls, ceiling, etc.) are separated in the time domain by this technique. The development of the range is continuing and planned future improvements will also be discussed.

Development of a low noise microwave frequency-synthesizer with low resolution

This paper describes an easy approach to realize a SMF X-band frequency synthesizer with a low resolution of 20 KHz. In a slightly modified mix-divide (Winchell 1980) approach, a comb-generator is used to work like a pre-scalar in the X-band, The noise content in the output is comparable with instrumentation synthesizers, though our approach has been developed using commerically available components and can be assembled without much difficulty in any electronics laboratory.

A Low-Noise Single Loop/Mix and Countdown Microwave Frequency Synthesizer for Satellite Links

(1983). A Low-Noise Single Loop/Mix and Countdown Microwave Frequency Synthesizer for Satellite Links. IETE Journal of Research: Vol. 29, No. 11, pp. 561-563.

New Microwave-Frequency Synthesizers that Exhibit Broader Bandwidths and Increased Spectral Purity

A superior microwave-frequency synthesis technique is treated in this paper, emphasizing improved spectral purity with octave bandwidths in the microwave region. The microwave-frequency synthesizer is discussed in two sections each corresponding to a system unit. The driver unit specifications are analyzed in the first section, showing its voltage-controlled crystal oscillator (VCXO) L(f ) output to be -130 dBc/Hz at 10 kHz. In the second section, the driver VCXO output is translated in the microwave unit to the final X-band frequency by means of a phase-locked loop. An analysis of this phase-locked loop, as described in this paper, shows the final L(f ) equal to -101 dBc/Hz at 10 kHz. Since a worst case situation was assumed, the final L(f ) is quite superior for octave bandwidth microwave-frequency synthesizers.