Corner-fed Square Research Articles

Array of waveguide-fed microstrip antennas

A low-cost Ku-band array of microstrip antennas, which is fed by standard waveguide, is presented in this article. The 72 corner-fed square patches of the array are arranged in a 6-by-12 configuration. A novel waveguide-to-microstrip transition with power divider is employed as the fed for the array to reduce the loss of the microstrip feed line. The resonant frequency of the array is 12.5 GHz and the gain was measured to be 24.3 dBi. The measurement results show good agreements with full-wave simulation. This array of waveguide-fed microstrip antennas can be used in many modern communication systems, such as a mobile radar sensor, in which the transition can be fixed as a connection between the module with a front-end waveguide and the antennas. © 2010 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2011.

Low cost, high efficiency, low side-lobe array of waveguide-fed microstrip antennas

A low-cost, low side-lobe Ku-band array of microstrip antennas, which is fed by waveguide, is presented in this article.The 72 corner-fed square patches of the array are arranged in a 6-by-12 configuration. A novel waveguide to microstrip line transition with power divider is employed as a center fed for the array to reduce the loss of the microstrip feed line. The measured gain is 24.1 dB. The side-lobe is below −20 dB, and the return loss at resonant frequency 12.5 GHz is less than −25 dB. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1582–1584, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25263

Polarization-Agile Microstrip Antenna Array Using a Single Phase-Shift Circuit

A novel polarization-agile microstrip antenna array is proposed, in which the polarization agility from linear to circular polarization for the whole array is realized easily by controlling a single phase-shift circuit. Using the corner-fed square patch element, a new 16 element dual-polarized array with high isolation and low cross-polarization is designed and analyzed by the extended multiport network method. A special FET phase shifter circuit is created, where 0/spl deg/ or 90/spl deg/ phase shift between dual ports is electrically switched. Experimental results are presented to verify the theory, and measured circularly-polarized radiation patterns show a boresight axial ratio of 0.5 dB. Another experiment that connects a low noise amplifier together with the phase-shift circuit is also introduced, realizing both polarization agility and power amplification with one active circuit.

FDTD analysis of serial corner-fed square patch antennas for single- and dual-polarised applications

The finite-difference time-domain (FDTD) method is developed for the analysis of serial corner-fed square patch antennas. A special technique to model the slanted metallic boundaries of the patch antenna has been used in the general FDTD algorithm to avoid the staircase approximations. The method improves the accuracy of the original FDTD algorithm without increasing its complexity. Both the one-port and two-port cases are studied, which are for single- and dual-polarised applications, respectively. Several antenna elements are manufactured. An isolation of -25 dB is achieved by the two-port antenna, which makes it suitable for many dual-polarised applications. The numerical analysis is confirmed by the experimental results and by results published elsewhere.