This paper describes the design and performance of a circularly polarized antenna for satellite communication applications. The includes monopole patch antenna, split ring resonator, defective ground surface metallic reflector. is designed to operate in multiple frequency bands have high gain. reflector used enhance gain by reflecting signal same phase as transmitted signal, thereby strengtheni...

A compact-size planar antenna with ultra-wideband (UWB) bandwidth and directional patterns is presented. The antenna can be fabricated on a printed circuit board (PCB). On one side of the PCB, it has a circular patch, and on the other side it has a slot-embedded ground plane with a fork-shaped feeding stub in the slot. Directional radiation is achieved by using a reflector below the antenna. To...

This paper proposes a sector base station antenna for mobile wireless communication systems employing multiple woodpile metamaterial reflectors and a multiband radiator that establishes the same beamwidth in the horizontal plane for more than two frequency bands. Electromagnetic Band Gap (EBG) characteristics of each metamaterial reflector can be controlled through structural parameters of the ...

Large size space deployable antenna structures are needed for a variety of applications. Current resources limitations within the antenna user community have resulted in the need for low cost, light weight and mechanically reliable space structures. An inflatable deployable antenna concept, under development at L’Garde has such great potential for satieing these requirements; it was selected fo...

A key limitation for future Small Satellite communications and radar missions will be available antenna reflector aperture. Two types of reflectors are dominant for satellite RF systems today, rigid, single-piece reflectors and deployable mesh reflectors. Single-piece reflectors are limited to the aperture that fits inside a launch vehicle without packaging the reflective surface. Mesh reflecto...

Antenna reflector losses play an important role in the calibration budget for a microwave radiometer. If the losses are small, they are difficult to measure by traditional means. However, they can be assessed directly by radiometric means using the sky brightness temperature as incident radiation. This paper describes how such measurements are carried out as well as a suitable experimental setu...

Reflector antenna optimization schemes using array feeds have been used to recover antenna losses resulting from antenna distortions and aberrations and to generate contour coverage patterns. IIistorically these optimization have been carried out using the antenna far-field scattered patterns. The far-field patterns must be calculated separately for each of the array feed elements. For large or...

Based on the VMS survey of the compact array antenna CA02, the effects of gravity deformation were examined in AT 39.3/115. The dominant cause of gain loss and beam distortion was identified to be the deformation of the main reflector surface with elevation. This report examines whether active displacements in the sub-reflector and/or feed might compensate for the aperture wavefront errors. All...

This paper presents a low profile dual polarized directional antenna composed of loop and dipole arrays mounted on a ground plane with each loops and dipoles being fed independently. Each loop antenna is paired with a reflector while each dipole antenna is paired with a director and a reflector. The proposed antenna is intended for an indoor base station (BS) with resonance frequency of 2.4 GHz...

Antenna reflector losses may play an important role in the calibration budget for a microwave radiometer. If the losses are small they are difficult to measure by traditional means. However, they can be assessed directly by radiometric means using the sky brighmess temperature as incident radiation. The paper describes how such measurements are carried out as well as a suitable experimental set...