By Topic

A Miniaturized and Broadband Balun Using Artificial Coupled Line With Imaginary Even-Mode Impedance

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
$31 $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

4 Author(s)
Chung-Hao Tsai ; Dept. of Electr. of Eng., Nat. Taiwan Univ., Taipei, Taiwan ; Iat-In Ao Leong ; Hung-Chuan Chen ; Tzong-Lin Wu

A broadband and miniaturized balun is proposed using the artificial coupled line with the imaginary even-mode impedance. The artificial coupled line is a metamaterial transmission line with zero electrical length for the even-mode excitation, whereas it behaves like a TEM transmission line with approximately constant characteristic impedance for the odd-mode excitation. Based on the artificial coupled line, a new concept to design a broadband balun is presented. The broadband characteristic of the balun is explained by the odd- and even-mode analysis. A balun is realized using low-temperature co-fired ceramic fabrication technology, simulated by a full-wave tool, and measured in the three-port vector network analyzer system. It exhibits good amplitude imbalance of 0.3 dB and phase imbalance of 179°±3° with the return loss greater than 10 dB from 3.3 to 7.1 GHz with 73% of fractional bandwidth. Its electrical size is only 0.063×0.44λ g2 and its physical size is 1.6×11.2 mm2. Compared with previous works, the proposed balun possessing good balance has a more compact size with broadband operation.

Published in:

Microwave Theory and Techniques, IEEE Transactions on  (Volume:59 ,  Issue: 9 )