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Cassegrain antenna

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


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Patent
16 Jun 2006
TL;DR: In this paper, the authors describe a millimeter-wave chip-array reflector antenna system that includes a reflector to shape and reflect an incident antenna beam and a chip array antenna comprising an array of antenna elements to direct the reflected antenna beam at the surface of the reflector.
Abstract: Embodiments of millimeter-wave chip-array reflector antenna system are generally described herein. Other embodiments may be described and claimed. In some embodiments, the millimeter-wave chip-array reflector antenna system includes a millimeter-wave reflector to shape and reflect an incident antenna beam and a chip-array antenna comprising an array of antenna elements to direct the incident antenna beam at the surface of the reflector to provide a reflected antenna beam.

14 citations

Patent
05 Dec 2001
TL;DR: In this paper, a wave-scanning antenna is disclosed that does not require a rotary joint, and the antenna produces a collimated beam that can be scanned through 360 degrees, where the energy emitted by the horn proceeds upward until deflected through an angle of 90 degrees by an angled reflector located on the axis of rotation.
Abstract: A wave-scanning antenna is disclosed that does not require a rotary joint. The antenna produces a collimated beam that can be scanned through 360 degrees. The beam is directed perpendicular to the antenna's axis of rotation to form a disc-like surveillance volume, or at an angle above or below the perpendicular to form a cone-shaped surveillance volume. The radar's structure contains a transmitter and receiver coupled to a horn protruding through open centers of the support bearing and driven gear into the antenna housing. Energy emitted by the horn proceeds upward until deflected through an angle of 90 degrees by an angled reflector located on the axis of rotation. The energy is collected by a dielectric lens and focused into a collimated beam. Reflected energy is collected by the lens and directed by the reflector to the horn, where it is fed to a waveguide coupled to the receiver.

14 citations

Patent
11 May 2006
TL;DR: In this article, a variable beam controlling antenna for a mobile communication base station having at least two radiator portions that are arranged vertically, with each portion having a reflector with at least one radiator installed therein.
Abstract: A variable beam controlling antenna for a mobile communication base station having at least two radiator portions that are arranged vertically, with each portion having a reflector with at least one radiator installed therein. At least one force generator provides rotational force when applied on external control signal, and a force transfer portion transfers the rotational force generated from the force generator to at least one reflector, thus rotating the at least one reflector. The variable beam controlling antenna can be fabricated at a low cost and allows for easy automatic optimization, which is required for a mobile communication wireless network since it is configured to be a one-column antenna capable of controlling a horizontal beam width. Although conventionally many kinds of antennas with different beam widths are needed for base station sectors, the single antenna can easily change its beam width.

14 citations

Proceedings ArticleDOI
01 Jan 2007
TL;DR: In this article, the electrical design of the Eleven feed for the parabolic reflector antennas of the giant meterwave radio telescope (GMRT-India) optimized for 200 to 800 MHz bandwidth is discussed.
Abstract: This paper discusses in brief the electrical design of the Eleven feed for the parabolic reflector antennas of Giant Meterwave Radio Telescope (GMRT-India) optimized for 200 to 800 MHz bandwidth. Paper also gives the comparison between the simulated and measured antenna input reflection coefficient and radiation patterns. The measured S11 of the feed is less than -8 dB and the computed total aperture efficiency including the mismatch losses, is better than -3.2 dB over desired bandwidth for the reflector antennas of GMRT having 62.5° of half subtended angle. (6 pages)

14 citations

Journal ArticleDOI
TL;DR: An uni-directional antenna designed by resonance-based reflector has the merits of compact size, low-profile, and ultra-wide impedance bandwidth, but its front to back ratio (FBR) bandwidth is narrow owing to the small reflection coefficient values at the high frequencies of the RBR in-phase band.
Abstract: An uni-directional antenna designed by resonance-based reflector has the merits of compact size, low-profile, and ultra-wide impedance bandwidth. However, its front to back ratio (FBR) bandwidth is narrow owing to the small reflection coefficient values at the high frequencies of the RBR in-phase band. To solve this problem, a ring-shaped director (RD) was placed above a resonance-based reflector-based antenna to guide the high frequencies. Then, the FBR bandwidth was enhanced. The proposed antenna achieves a wide measured impedance bandwidth from 2.17 to 3.76 GHz (53.6%). Its FBR band (FBR >7 dB) covers the whole operational band and the FBR >10-dB band covers 2.17–2.58 GHz (17.3%). The proposed antenna consists of a bow-tie element, a ring-shaped resonance-based reflector under the bow-tie element and an RD above the bow-tie element to form a sandwich configuration. The profile of the proposed antenna is only $0.16~\lambda $ at the lowest frequency of 2.17 GHz. To further evaluate the performances of the proposed antenna, the time-domain characteristics of the antenna were analyzed in terms of group delay, waveform response, correlation coefficient, and pulsewidth stretch ratio. Good time-domain characteristics were observed.

14 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202318
202267
202111
202018
201920
201824