By Topic

Characteristics and design of broadside-coupled transmission line at a higher order leaky mode

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

2 Author(s)
Huang, K.-F.S. ; Dept. of Commun. Eng., Nat. Chiao Tung Univ., Hsinchu, Taiwan ; Tzuang, C.-K.C.

The aim of this paper is to provide: (1) a detailed description of the higher order leaky modes of the much-used broadside-coupled microstrips, and (2) demonstrate the practical application of such leaky modes as an antenna. A representative broadside-coupled transmission-line structure is examined to elucidate the detail of leakage effects at higher order of multilayered three-dimensional microwave and millimeter-wave circuits. Two-layer cases are analyzed from a physical perspective and the total number of first higher order leaky modes is found to be equal to that of microstrips. One of the two first higher order leaky modes obtained in the two-layer case is weakly attenuated, while the other is strongly attenuated. A high-gain narrow-beam leaky-mode antenna using only the weakly attenuated leaky mode is designed and measured as an application of this broadside-coupled structure, exhibiting a marked beamwidth reduction of 60%. This antenna is the first Yagi-Uda-like array antenna that utilizes the higher order leaky modes of the microstrip, for which the three basic elements-driver, reflector, and director-are stacked in the broadside direction. The attenuation rate can be further reduced by adjusting the strip width of the director. The half-power beamwidth of the leaky-mode antenna applying two-layer broadside-coupled microstrips with a wider top microstrip is measured to be 2.10° at 25.20° from the broadside at 34 GHz.

Published in:

Microwave Theory and Techniques, IEEE Transactions on  (Volume:51 ,  Issue: 2 )