Cassegrain antenna

About: Cassegrain antenna is a research topic. Over the lifetime, 3207 publications have been published within this topic receiving 28278 citations.

Development of low RCS reflector antenna systems

Abstract: Reflector antenna systems for ground based and line of sight communication systems play a vital role in the transfer of information for both military and civilian communication purposes. Previously, these reflector antenna systems have been designed predominantly on the antenna's transmitting and receiving characteristics. Such parameters typically include: main beam width, side lobe levels, and cross polarization levels. It is only recently that the vulnerability to detection, i.e. the radar cross section (RCS) of these antenna systems, has been of concern. Studies on the scattering characteristics of such reflector antennas have revealed that the RCS characteristics of these antennas consist of three coupled phenomenon, each of which contributes to different aspects of the antenna's overall RCS. The phenomenon of most concern (though not necessarily the largest) is the direct reflection from the reflector surface itself. This paper presents a formal mathematical procedure for the synthesis of a new reflector surface which nearly preserves the original reflector antenna pattern while removing the possibility of direct radar reflection from the reflector surface in the regions of space where low RCS is required.

Three-dimensional corner reflector antenna

Abstract: A reflector antenna utilizing three planar reflectors and a 3/4 λ-unipole radiator is proposed. Calculations based on image- and EMF-methods predict that the gain is about 5 dB greater than that of the two-dimensional corner reflector antenna, and that the input impedance is roughly between 50 and 75 Ω. Experiments conducted on the three-dimensional corner reflector antenna with rectangular corners confirmed the predicted properties and also showed the sidelobe in the electric plane being suppressed by the effect of diffraction. This effect is explained by the calculated radiation pattern of 3/4 λ-unipole on conducting half plate

Time-domain physical-optics analysis of large reflector antennas

Abstract: The time-domain analysis of large reflector antennas is presented. Physical-optics time-domain analysis is used to determine the antenna characteristics under pulse-modulated RF excitation. The resulting far fields for a front-fed paraboloid are shown. The waveforms of the incident wave and scattered field are plotted. From these patterns one can determine buildup and decay transient time as a function of reflector diameter or observer look angle. Using the peak of the steady-state field for different look angles, one can determine the gain pattern of the reflector, which agrees exactly with the gain pattern obtained directly from frequency-domain analysis. >