We develop a simple model for a feed horn with a uniformly excited circular aperture at the focus of an offset paraboloidal reflector antenna and compare it with reflector antenna analyses using combinations of circular waveguide TE1n modes. The model demonstrates the deep dip that can occur at the spot-beam center for certain feed diameters and it is used in a design procedure that relates the...

A microstrip reflectarray is a flat reflector antenna that can be mounted conformally onto a spacecraft’s outside structure without consuming a significant amount of spacecraft volume and mass. For large apertures (2 m or larger), the antenna’s reflecting surface, being flat, can be more easily and reliably deployed than a curved parabolic reflector. This article presents the study results on a...

A millimeter wave antenna measurement system is presented. The frequencies of operation are around 100 GHz and 300 GHz (W/J Bands). The facility is a single reflector compact range system. Design tasks deal with the serrated reflector and the corresponding millimeter wave instrumentation design.

We consider here antemas that could be usefid as part of a fize radar for penetrating munitions. The concept requires radiating an ultra-short pulse using an antenna with maximum gain and a compact design. Both lens and reflector Impulse Radiating Antennas (IRAs) are recommended as suitable candidates for this purpose. We summarize the properties of these antennas, and we describe two measureme...

A W-band dual-polarized Cassegrain antenna for cloud radar is proposed. The aperture diameter of the main reflector of the antenna is 50 cm. By using a modified Magic-T structure in the feed horn, the antenna is dual-polarized with high port isolation. The measured results show that the port isolation is 44.7 dB. The gains are 47.3 dB and 49.5 dB for the two ports at 94GHz, respectively, and th...

The synthesis of steerable reflect-array antennas, as a synthesis of any antenna, should be realized by solving two problems: external antenna problem and internal antenna problem. The first one includes the investigation of the antenna radiation pattern. The second one concerns a design of the structure providing the required amplitude-and-phase distribution along the antenna aperture. The fir...

This paper presents a new compact end-fire antenna for ultra-high frequency (UHF) radio frequency identification (RFID) applications. The antenna has two meandered dipole drivers. A folded reflector and a rectangular reflector are demonstrated. The advantage of the end-fire antenna with meander dipole drivers compared to the conventional quasi-Yagi antenna is a reduction in the length of the dr...

This article proposes an approach to increase the efficiency of the U-shaped cross section antenna. The Optimization of a wideband U-shaped cross section antenna on a U-shaped ground plane is presented suitable for WLAN in various applications. The proposed antenna has been developed from a single element of U-shaped cross-sectional antenna. A single element is easy to be composed for installin...

In this paper a dual band and high gain H-plane horn antenna implemented by substrate integrated waveguide (SIW) using a single layer thin substrate is introduced. The proposed antenna consists of five parts of rectangular waveguide with different width arranged in a staircase manner to allow mode combination of fundamental and higher propagating modes of the structure. By adjusting the length ...

This paper presents the shaping optimization of an S-band cylindrical offset reflector antenna with cosecant-squared radiation pattern in elevation plane. The cross section of the antenna is mathematically modeled by a polynomial function and optimized by the genetic algorithm to obtain the desired pattern for both TE and TM polarizations. The physical optics method together with the uniform th...