Using phase relations in microstrip directional couplers to achieve high directivity

Date
2013
Authors
Tas, V.
Atalar, Abdullah
Advisor
Instructor
Source Title
IEEE Transactions on Microwave Theory and Techniques
Print ISSN
0018-9480
Electronic ISSN
Publisher
Volume
61
Issue
12
Pages
4063 - 4071
Language
English
Type
Article
Journal Title
Journal ISSN
Volume Title
Abstract

We analyze the microstrip directional couplers with a special focus on the phase difference between the coupled and isolated ports. The analysis uses the even-odd mode decomposition technique and network theory. The results show that the phase difference between the signals at the coupled port and the isolated port is close to \pi in a very wide band. This property can be used to achieve a broadband directivity by inducing a voltage cancellation at the isolated port of the couplers. Two different cancellation methods are investigated. Analytical formulas for the required component values of both methods are given. Higher directivity can be obtained at the expense of reduced bandwidth.

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Book Title
Keywords
Broadband microstrip coupler, Coupler phase relations, Coupling isolation phase difference, High directivity, Analytical formulas, High-directivity, Isolated ports, Microstrip coupler, Mode decomposition techniques, Phase difference, Phase relation, Reduced bandwidths, Microwave circuits, Microwaves, Directional couplers
Citation
Published Version (Please cite this version)