High Gain Conformal Super High Frequency Antenna

A high gain conformal antenna is proposed having E-shaped patch to be used in SHF frequency range. A comprehensive parametric study has been carried out to understand the effects of various dielectric substrate effects and to optimize the performance of the antenna. For various substrate materials the effect of dielectric constant, loss tangent, mass density, bulk conductivity is observed .Results are compared in two simulation software and found in good agreement. Key WordsConformal antenna, tri-band ,high gain, E-shaped Patch. I Now a days SHF frequencies occupy a "sweet spot" in the radio spectrum which is currently being exploited by many new radio services. They are the lowest frequency band where radio waves can be directed in narrow beams by conveniently sized antennas so they do not interfere with nearby transmitters on the same frequency, allowing frequency reuse. On the other hand, they are the highest frequencies which can be used for long distance terrestrial communication. Conformal antenna attracting wide acceptability in field of antenna design due to its low profile, small size and ease of handling. . A characteristic phenomenon of patch antennas Conformal to curved platforms is the dependence of resonant input impedance on surface curvature [10]. Understanding how surface curvature affects the input impedance and resonant frequency is crucial for matching with the feed network and efficient radiation. In light of this, it is vital that conformal antenna models include surface curvature so that the effect of surface geometry on their performance can be predicted more accurately. As wireless systems continue to enjoy increased application and gain wider acceptance, performance and cost constraints on the antennas employed by these systems become more difficult to meet. Antennas that are conformal or low profile and that exhibit ultra wideband operation are of particular interest for many of these new systems. Concomitant with increased performance levels is the need for antenna designs with the potential for low cost manufacturing. To address the requirements and the severe constraints imposed by commercial application of these antennas, new innovative antenna design methodologies are required. To date, most new wireless system antenna designs have been derived from existing canonical designs such as the monopole and wavelength patch antennas. Various feeding mechanism has been studied this far such as micro-strip line ,coaxial probe, aperture coupling and proximity coupling[1],[2],[3],[4],[5],[6][7].Here in this paper a cylindrically conformed version of E-shaped patch antenna[20] is proposed which is the extended work of previously proposed E-shaped planar antenna[9] Waveguide feeding is proposed in this paper. The advantages of an antenna that resembles the shape of the object to which it is attached are obvious. Some thinner varieties of microstrip that are commercially available today can change from their planar shape to represent some part of a cylinder [2]. The antenna proposed in this work is derived from a previously designed E-shaped planar antenna and being conformal it is having bandwidth better than the previous one. Different dielectric constant are examined to obtain desired characteristics and result are compared in HFSS and CST Microwave studio. The results are in good agreement the role of dielectric constant is to shift of resonant frequency. The paper is organized as follow. Section II deals with designing of patch and the antenna.III deals with study of different dielectric materials. IV is for results and discussion and V deals with