Showing papers on "Metamaterial antenna published in 1982"

Design of microstrip antennas covered with a dielectric layer

Abstract: The design of a microstrip antenna covered with a dielectric layer is presented. Due to loading, the resonant frequency of the antenna changes. The absolute value of the change increases with the operating frequency, the relative permittivity (except plasma), and the thickness of the dielectric layer. This change may cause degradation in performance due to the inherent narrow bandwidth of microstrip antennas if the effect of loading is not considered in the design. The curves presented here may be used to design microstrip antennas that may be subjected to icing or a plasma environment or coated with protective layers. Numerical and experimental results for the fractional change in the resonant frequency are round to be in good agreement.

A frequency agile microstrip antenna

Abstract: This paper describes a novel technique for increasing the operational frequency bandwidth of microstrip patch antennas, by using varactor diodes at the radiating edges of the structure. Theoretical and experimental results confirm that bandwidths of the order of 30% are achievable compared to 1-2% for the unloaded patch radiator.

Broadband circular disc microstrip antenna

Abstract: A technique for broadening the bandwidth of the circular disc microstrip radiating element is described. Theory based on a simple circuit model is introduced and comparison with experimental work is shown. From this model, a matching circuit is devised, the resulting element giving a bandwidth of 35% (to a VSWR of 1.5) near 8 GHz. This makes the circular disc element suitable for a wide range of radar and communications antenna systems.