PROJECT TITLE :

A Novel -TEM Mixed-Mode Converter

ABSTRACT:

Overmoded relativistic backward wave oscillators cannot preserve output mode purity, generating a number of TM0n modes generally. Until currently, terminations for prime power microwave (HPM) devices are only matched to a single operating mode. It is quite difficult to properly radiate a mix of TM0n modes using HPM antennas. In this paper, a unique efficient TM0n-TEM-mode converter is proposed. With the strategy of power dividing and field matching described, a combination of TM01, TM02, and TM03 modes generated by an HPM device can be successfully converted into a pure coaxial circular waveguide TEM mode utilizing the outer and inner coaxial waveguide structure with an potency of over ninety nine% at the center frequency. Such a mode transition will greatly improve the radiation potency of HPM antennas.