THE TE01 WAVE EXCITATION IN A CIRCULAR WAVEGUIDE USING HIGHER-ORDER MODES OF AN OPEN RESONATOR

Abstract

Subject and Purpose. Peculiarities of the TE01 wave excitation in a circular waveguide located in the center of the flat mirror of a hemispherical open resonator (OR) are studied using the OR oscillation type TEM30q and the OR degenerate oscillation type TEM in the extremely high frequency (EHF) range. Methods and Methodology. The efficiency of the circular-waveguide TE01 wave excitation using the TEM30q and TEM11q types of OR oscillations is evaluated through the factor of antenna surface utilization. Amplitude distributions of the OR oscillation fields were measured by the trial body method. Results. It has been established that the efficiency, h, of the TE01 wave excitation in the circular waveguide is not high when it is by use of the OR oscillation ТЕМ30q. Things are different when the TE01 wave is excited with the inner ring of the TEM11q degenerate oscillation field whereby the h value shoots up to 95.5%, the circular waveguide section radius being a = 0.993w0, where w0 is the radius of the field spot of the main oscillation type TEM00q on the OR flat mirror. The experimental studies have confirmed that the TE01 wave excitation in the waveguide has high efficiency. The attachment of the circular oversized waveguide section worsens the OR loss by no more than 0.9 dB. The presence of the circular waveguide makes the TEM3012 oscillation type transform into the TEM1112 degenerate oscillation. Conclusions. The considered OR can be used as a storage resonator in the construction of electromagnetic pulse compressors in the EHF range, since the resonant system loss increases insignificantly, and the circular waveguide itself is oversized. It is easy to implement an interference switch in such a waveguide.