Accession Number : AD0270918

Title :   FREQUENCY SCANNING OF SLOW WAVE ANTENNAS

Corporate Author : WASHINGTON UNIV SEATTLE

Personal Author(s) : ISHIMARU,AKIRA ; HSIEH,CHYANG

Report Date : AUG 1961

Pagination or Media Count : 1

Abstract : An experimental study is presented of a frequency scanning antenna. The slow wave structure employed is a rectangular waveguide containing corrugations on the bottom of the guide. The propagation characteristics of the allowable mode configurations which can exist inside this structure were solved under the assumption of average constant impedance on the top surface of the corrugations. The slow wave antenna is constructed by cutting slot arrays on the broad side of this waveguide with the long dimension of the slots along the corrugations and with spacings between adjacent slots equal to the guide wavelength at the center frequency. Frequency scanning characteristics of the slow wave antenna were studied by taking radiation patterns for different frequencies. Results show that the angle at which the main beam occurs can be scanned from -72 to 28 degrees by changing the frequency between 9.3 and 10.5 kmc. (Author)

Descriptors :   *SLOT ANTENNAS, *WAVEGUIDE SLOTS, ANTENNA RADIATION PATTERNS, ANTENNAS, ATTENUATION, ELECTROMAGNETIC FIELDS, ELECTROMAGNETIC PROPERTIES, MATHEMATICAL ANALYSIS, MEASUREMENT, MICROWAVE EQUIPMENT, MICROWAVES, PROPAGATION, X BAND

Distribution Statement : APPROVED FOR PUBLIC RELEASE