Ground based space debris radar system utilizing a multibeam reflector antenna and digital beam-forming techniques allows a tracking of target within a large angular segment and supports the realization of an advanced Track While Scan mode characterized by a large search volume and simultaneous high detection and capture probabilities. This paper considers the concept and the main operational p...

We present the formulation and experimental results of a new approach to designing internal mode converter reflectors for high-power gyrotrons. The method employs a numerical phase retrieval algorithm that reconstructs the field in the mode converter from intensity measurements, thus accounting for the true field structure in shaping the beam-forming reflectors. An outline for designing a four-...

Interferometric telescopes made of close-packed antenna elements are an important tool for imaging extended radio sources, specifically structures that have angular sizes comparable to or even greater than the FWHM of the beams of the antennas. They have proved useful in observations of cosmic microwave background anisotropies that require high brightness-sensitivity. However, the visibilities ...

Two offset IRAs are numerically modeled and analyzed. The reflector of the offset IRA is an offset portion of a paraboloid that is carved out by the intersection of the paraboloid and a cone whose apex is at the focal point of the paraboloid. A pair of conical curved plates is placed on the surface of the cone as TEM feed arms. The TEM feed arm of the first IRA is conical throughout its length ...

detection of stealth targets calls for employment of high-power radars which itself relies on usage of high-gain antennas like large parabolic reflectors. in the past few years, using of an array with many small reflectors instead of a large reflector antenna has been considered. this method provides enhanced eirp by a factor of n2 where n is the number of array antennas. regarding improvement ...

1 Introduction The previous researches on the modulated scattering antenna array (MSAA) have shown that the second-order intermodulation scattering signal is relatively low compared with the direct received signal [1]. In this report, a switched reflector is used to solve this problem. The diversity performance of the MSAA with a switched reflector is investigated. It is shown that the diversit...

We present cathodoluminescence experiments that quantify the response of plasmonic Yagi-Uda antennas fabricated on one-dimensional silicon nitride waveguides as function of electron beam excitation position and emission wavelength. At the near-infrared antenna design wavelength cathodoluminescence signal robustly is strongest when exciting the antenna at the reflector element. Yet at just sligh...