A Single-Ridged Coaxial Hybrid TE011 Coupler with High Mode Purity
Authors: Choi, J.J.; Han, W.K.
Source: International Journal of Infrared and Millimeter Waves, Volume 21, Number 12, December 2000 , pp. 2035-2046(12)
Abstract:We design a single-ridged coaxial hybrid coupler which excites a TE_011 mode of high mode content in a cylindrical cavity, resonating at 28.2GHz. The coupler consists of a WR-28 rectangular waveguide, a coaxial TE_n11 cavity, and a cylindrical TE_011 cavity. Both TE_311 coaxial cavity and TE_411 single-ridged coaxial cavity are analyzed to examine the TE_011 mode purity in the central cavity. Mode purity analysis is performed by a field expansion method using Fourier-Bessel orthonormal basis functions. Numerical calculations predict that the TE_411 single-ridged coaxial cavity excites the TE_011 mode with mode purity of 98.6%, which is improved by 3% higher compared with the TE_311 coaxial cavity. Measurements on the single-ridged coaxial coupler show a resonant frequency at 28.078GHz and ohmic and external Qs of 1560, 473 respectively, which are in good agreement with the simulated results of a 3-D finite element electromagnetic code.
Document Type: Regular Paper
Affiliations: High Power Microwave Engineering Laboratory, Department of Radio Sciences and Engineering, Kwangwoon University, Seoul, 139-701 Korea
Publication date: December 1, 2000