Microstrip Leaky-Wave Antenna With Control of Leakage Rate and Only One Main Beam in the Azimuthal Plane

An original leaky-wave antenna (LWA), conceived from a microstrip line which is laterally shielded by parallel plates, is presented in this paper. This structure shows, for the first time, that the leakage rate of a microstrip leaky-mode can be easily controlled while negligibly affecting the pointing direction. The antenna is based on the radiation from the second higher order mode of the microstrip line, which is perturbed by the addition of the two conductor walls to control the level of the leakage rate. The parallel-plates also serve as a mechanism to obtain a single main beam in the azimuthal plane, therefore improving the radiation pattern compared to common dual-beam second-higher order mode microstrip LWAs. The proposed antenna is analyzed by obtaining the corresponding leaky-mode complex propagation constant, which is calculated by a specific method of moments approach. The modal results obtained from the leaky-mode dispersion curves are validated with analysis performed on a three-dimensional structure using commercial finite element method solver. Also, a prototype is fabricated to experimentally confirm the advantages of this novel leaky-wave line source.

[1]  A. A. Oliner,et al.  A New Leaky Waveguide for Millimeter Waves Using Nonradiative Dielectric (NRD) Waveguide-Part II: Comparison with Experiments , 1987 .

[2]  W. Menzel,et al.  A New Travelling Wave Antenna in Microstrip , 1978, 1978 8th European Microwave Conference.

[3]  Jyh-Wen Sheen,et al.  Analysis and design of feeding structures for microstrip leaky wave antenna , 1995, IMS 1995.

[4]  Ching-Kuang C. Tzuang,et al.  A dual-beam micro-CPW leaky-mode antenna , 2000 .

[5]  Jyh-Wen Sheen,et al.  Mode distinction and radiation-efficiency analysis of planar leaky-wave line source , 1997 .

[6]  T. Yoneyama.  Nonradiative dielectric waveguide , 1984 .

[7]  Yu-De Lin,et al.  Aperture-coupled microstrip second higher order leaky-mode antenna , 2001, APMC 2001. 2001 Asia-Pacific Microwave Conference (Cat. No.01TH8577).

[8]  Yu-De Lin,et al.  Microstrip leaky-wave antenna fed by short-end CPW-to-slot transition , 1999 .

[9]  Yu-De Lin,et al.  Microstrip-fed microstrip second higher order leaky-mode antenna , 2001 .

[10]  D. Jackson,et al.  Leaky‐Wave Antennas , 2008 .

[11]  Alejandro Álvarez Melcón,et al.  A full‐wave space‐domain method for the analysis of leaky‐wave modes in multilayered planar open parallel‐plate waveguides , 2005 .

[12]  Yu-De Lin,et al.  Design of the feeding structures for the excitation of the microstrip line second higher order mode leaky-wave antenna , 1997 .

[13]  Ching-Kuang C. Tzuang,et al.  Oscillator-type active-integrated antenna: the leaky-mode approach , 1996 .

[14]  J. Stén,et al.  Reconstruction of electromagnetic minimum energy sources in a prolate spheroid , 2004 .

[15]  Tai-Lee Chen,et al.  Broadband tapered microstrip leaky-wave antenna , 2003 .

[16]  A. Oliner,et al.  Microstrip leaky wave strip antennas , 1986, 1986 Antennas and Propagation Society International Symposium.

[17]  Arthur A. Oliner,et al.  Leakage from higher modes on microstrip line with application to antennas , 1987 .

[18]  E. Yamashita,et al.  Space wave leakage from higher order modes on various planar transmission line structures , 1994, 1994 IEEE MTT-S International Microwave Symposium Digest (Cat. No.94CH3389-4).

[19]  Alejandro Álvarez Melcón,et al.  Radiation analysis in the space domain of laterally shielded planar transmission lines: 1. Theory , 2003 .

[20]  D. P. Nyquist,et al.  Identification of propagation regimes on integrated microstrip transmission lines , 1993 .

[21]  Yu-De Lin,et al.  Aperture-coupled microstrip line leaky wave antenna with broadside mainbeam , 1998 .

[22]  Helmut Ermert,et al.  Guiding and radiation characteristics of planar waveguides , 1979 .

[23]  Alejandro Álvarez Melcón,et al.  Radiation analysis in the space domain of laterally shielded planar transmission lines , 2003, IEEE Antennas and Propagation Society International Symposium. Digest. Held in conjunction with: USNC/CNC/URSI North American Radio Sci. Meeting (Cat. No.03CH37450).

[24]  A. Oliner,et al.  A New Leaky Waveguide for Millimeter Waves Using Nonradiative Dielectric (NRD) Waveguide-Part I: Accurate Theory , 1987 .