By Topic

Compact Microstrip 3-dB Coupled-Line Ring and Branch-Line Hybrids With New Symmetric Equivalent Circuits

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

Formats Non-Member Member
$33 $13
Learn how you can qualify for the best price for this item!
Become an IEEE Member or Subscribe to
IEEE Xplore for exclusive pricing!
close button

puzzle piece

IEEE membership options for an individual and IEEE Xplore subscriptions for an organization offer the most affordable access to essential journal articles, conference papers, standards, eBooks, and eLearning courses.

Learn more about:

IEEE membership

IEEE Xplore subscriptions

2 Author(s)
Hee-Ran Ahn ; School of Electrical Engineering and Computer Science, Seoul National University, Seoul, Korea ; Sangwook Nam

New symmetric equivalent circuits are suggested for 90° and 270° transmission-line sections, with which compact coupled-line ring and branch-line hybrids can be designed and fabricated. For this purpose, firstly stepped-impedance transmission-line (SITL) sections, being equivalent to a uniform transmission-line section with arbitrary electrical lengths, are synthesized, and design formulas for the SITL sections are derived. Secondly, three types of equivalent circuits are introduced by combining the SITL sections with coupled-line Π-, modified Π-, or T-type, and are called stepped-impedance coupled-line Π-type (SCΠ ), stepped-impedance modified T-type (SMT), and stepped-impedance modified Π-type (SMΠ). The SCΠs are for 270° transmission-line sections, while both SMTs and SMΠs are for 90° transmission-line sections. Based on the suggested equivalent circuits, compact coupled-line ring and branch-line hybrids designed at 1 GHz are fabricated, and the measured bandwidth of the ring hybrid is 50% with 15-dB return loss. The measured results may be considered as excellent, reflecting their total transmission-line lengths of 183° and 111° for the ring and branch-line hybrids, respectively.

Published in:

IEEE Transactions on Microwave Theory and Techniques  (Volume:61 ,  Issue: 3 )