Bandwidth-enhanced single-layer 3-dB tandem directional coupler as magic-T network

A new approach to the design of a very broadband magic-T network focused on a single-layer realization has been proposed. In order to obtain wide bandwidth, a recently developed technique of bandwidth enhancement of tandem connected loosely coupled directional couplers has been employed. It has been shown that utilizing single-section coupled-line couplers one can realize a planar tandem coupler featuring frequency characteristics similar to these of a two-section coupled-line couplers. The proposed approach has been verified by the design and measurement of a 3-dB tandem coupler operating within 0.6-2.0 GHz frequency range with amplitude imbalance of ±0.45 dB, and the theoretical analysis of differential phase shaping to obtain magic-T properties.

[1]  Yongle Wu,et al.  Single-Layer Microstrip High-Directivity Coupled-Line Coupler With Tight Coupling , 2013, IEEE Transactions on Microwave Theory and Techniques.

[2]  J. Lange.  Interdigitated Stripline Quadrature Hybrid (Correspondence) , 1969 .

[3]  Krzysztof Wincza,et al.  Broadband magic-Ts with the use of coupled-line directional couplers and left-handed transmission line sections , 2014 .

[4]  H. J. Hindin,et al.  3-db Couplers Constructed from Two Tandem Connected 8.34-dB Asymmetric Couplers (Correspondence) , 1968 .

[5]  Krzysztof Wincza,et al.  A Broadband 3 dB Tandem Coupler Utilizing Right/Left Handed Transmission Line Sections , 2014, IEEE Microwave and Wireless Components Letters.

[6]  Krzysztof Wincza,et al.  Generalized Methods for the Design of Quasi-Ideal Symmetric and Asymmetric Coupled-Line Sections and Directional Couplers , 2011, IEEE Transactions on Microwave Theory and Techniques.

[7]  Sang-Won Yun,et al.  A design of wideband 3-dB coupler with N-section microstrip tandem structure , 2005 .

[8]  Ching-Wen Tang,et al.  Design of the Modified Planar Tandem Couplers With a Wide Passband , 2013, IEEE Transactions on Microwave Theory and Techniques.

[9]  A. R. Djordjević.  Matric parameters for multiconductor transmission lines : software and user's manual , 1989 .

[10]  Krzysztof Wincza,et al.  Directional couplers with reduced coupling requirements as connection of coupled-line sections and left-handed transmission lines , 2014 .