Topic
Active antenna
About: Active antenna is a research topic. Over the lifetime, 2246 publications have been published within this topic receiving 26493 citations.
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28 Jun 1993
TL;DR: SPOT-Radar as mentioned in this paper is the project for an X-band synthetic aperture radar (SAR) reusing the ground segment of SPOT, which has demonstrated that 768 patches, 100 T/R (transmit/receive) active modules, three power supplies, and six microstrip power dividers can be integrated on a very limited surface (0.57 /spl times/ 0.45 square meters), with a total mass of less than 8 kg.
Abstract: SPOT-Radar is the project for an X-band synthetic aperture radar (SAR) reusing the ground segment of SPOT. The subpanel active antenna demonstrator has demonstrated that 768 patches, 100 T/R (transmit/receive) active modules, three power supplies, and six microstrip power dividers can be integrated on a very limited surface (0.57 /spl times/ 0.45 square meters), with a total mass of less than 8 kg. All equipment has been electrically and mechanically designed in connection with launch vibrations, and temperature variations during in-orbit transfer and safe mode. >
3 citations
Patent•
23 Jul 2014
TL;DR: In this article, a narrow-frame reconfigurable antenna system of the utility model is applied to a mobile terminal device, which is printed on a terminal device circuit board, and comprises an antenna radiation unit, a feeder line, a surface-mounted diode, a DC power supply, a matching circuit and a metal ground.
Abstract: The utility model relates to a narrow-frame reconfigurable antenna system applied to a mobile terminal device The reconfigurable antenna system is printed on a terminal device circuit board, and comprises an antenna radiation unit, a feeder line, a surface-mounted diode, a DC power supply, a matching circuit and a metal ground; the antenna radiation unit includes a folding dual-branch active antenna unit and a folding coupled antenna unit; according to the reconfigurable narrow-frame antenna system uses the DC power supply and a bias circuit to control an on-off of a PIN diode; an inductor adds to a DC bias circuit so as to block an AC from the antenna; a metal floor is located at the back side of the antenna; and at the same time, a plastic shell is introduced in the antenna design process, so as to better simulate mobile terminal device environment in a real wireless communication system The narrow-frame reconfigurable antenna system of the utility model has the advantages of being multi-band, narrow-frame, small, and compact, realizes the GSM850 / 900 / 1800 / 1900 / UMTS2100 / LTE2300 / 2500 broadband coverage, and has the characteristics of being suitable for the mobile terminal device especially the narrow-frame mobile terminal device
3 citations
17 May 1995
TL;DR: In this paper, an active antenna array system capable of switching between sum and difference patterns for radar applications is explored, where the desired phase relationship among the antenna elements is synthesized via injection locking.
Abstract: An active antenna array system, capable of switching between sum and difference patterns for radar applications, is explored. The desired phase relationship amongst the antenna elements is synthesized via injection locking. An optical reference signal is transmitted from remote controller through the optical fiber link. The measured patterns agree with the theoretical results.
3 citations
TL;DR: In this paper, two modifications of compressive sensing (CS)-based approach applied to the near-field diagnosis of active phased arrays are presented, taking into account of thermal instability of the array by using an iterative l 1-minimization procedure.
Abstract: This paper presents two modifications of compressive sensing (CS)-based approach applied to the near-field diagnosis of active phased arrays. CS-based antenna array diagnosis allows a significant reduction of measurement time, which is crucial for the characterization of electrically large active antenna arrays, e.g. used in synthetic aperture radar. However, practical implementation of this method is limited by two factors: first, it is sensitive to thermal instabilities of the array under test, and second, excitation reconstruction accuracy strongly depends on the accuracy of the elements of the measurement matrix. First proposed modification allows taking into account of thermal instability of the array by using an iterative l1-minimization procedure. The second modification increases the accuracy of reconstruction using several simple additional measurements.
3 citations
Patent•
20 Jan 2017
TL;DR: In this article, the performance of an electrically small antenna with an antenna feed and a non-foster circuit has been investigated for increasing the received signal power of the antenna.
Abstract: In examples, systems and methods for increasing the performance of electrically-small antennas are described. An example system comprises an electrically-small antenna having an antenna feed. The electrically-small antenna is configured to receive a signal. The system also comprises a non-foster circuit having a negative capacitance coupled to the antenna feed in a shunt position. The non-foster circuit is configured to resonate the electrically-small antenna and provide a voltage increase to the received signal. The system also comprises a buffer circuit configured to provide an impedance conversion of the voltage-increased received signal between the antenna feed and an output of the buffer circuit. The buffer circuit includes a field-effect transistor.
2 citations