A new compact dual-band, dual-polarized microstrip antenna is presented. This antenna resonates at two frequencies with different polarizations: a linearly polarized one for terrestrial communication, and a circularly polarized one for satellite mobile communication. This antenna also pro¨ides an area reduction of 70% compared to a standard rectangular patch antenna. ᮊ

Experimental and simulated results for a dual‐port dual‐polarized microstrip antenna are presented. The antenna excites two orthogonally polarized resonant frequencies providing an isolation of ∼30 dB between the ports. The patch geometry consists of two circular arcs of different radii with their centers displaced by a distance. This new design offers an area reduction of ∼70% compared to a standard rectangular microstrip antenna with a reduction in gain of 1.7 dB. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 34: 459–460, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10494

frequency band used in many wireless communication applications, the patch size would be only 2 cm = 2 cm and 1.6 cm thick, which is small enough for many applications.The effects of the size and placement of the notches on the operation of the antenna were investigated next. The dimensions N, D, and D were varied, where N governs the 2 ABSTRACT: Dual-frequency operation is achie¨ed from a compact microstrip antenna by loading a pair of narrow slots close to its radiating edges. The two frequencies ha¨e parallel polarization planes and similar radiation characteristics. The ratio between the two operating frequencies ( ) can be tuned in the range 1.14᎐1.24 , which is much smaller than that of similar designs. The abo¨e excellent radiation characteristics are achie¨ed along with an area reduction of ;75% compared to the standard rectangular patch.

Design equations are presented for calculating the resonance frequencies for a compact dual frequency arrow-shaped microstrip antenna. This provides a fast and simple way to predict the resonant frequencies of the antenna. The antenna is also analyzed using the IE3D simulation package. The theoretical predictions are found to be very close to the IE3D results and thus establish the validity of the design formulae.

A linear array antenna design with desired radiation pattern has been presented based on genetic algorithm (GA) approach. Examples of cosecant and flat-topped beam patterns are illustrated to show the flexibility of GA to solve complex antenna synthesis problems by suitably selecting the fitness function, even with a simple GA. The results have been validated by IE3D electromagnetic simulation. The antenna arrays with different element geometries can also be implemented using the proposed technique. V V C 2008 Wiley Periodicals, Inc. Int J RF and Microwave CAE 18: 410-416, 2008.