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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Patent•
21 Jan 2021
TL;DR: In this article, the authors present an active antenna unit delay alignment method and apparatus, which can take into consideration large range and high precision delay alignment requirements, thereby solving the problems in the prior art of fixed compensation values and being unable to implement automatic correction.
Abstract: Disclosed in the embodiments of the present invention are an active antenna unit delay alignment method and apparatus, and an active antenna unit, the method comprising: on the basis of a front-haul interface protocol, generating an air interface synchronisation identifier; on the basis of the air interface synchronisation identifier, generating an alignment identifier and, on the basis of the alignment identifier, aligning the antenna data delay. By means of the technical solution of the air interface synchronisation identifier, the present method can automatically correct delays, and can take into consideration large range and high precision delay alignment requirements, thereby solving the problems in the prior art of fixed compensation values and being unable to implement automatic correction.
Patent•
19 Sep 1995
TL;DR: In this paper, a number of elements of a divided signal are applied to the parts according to a predetermined phase law on reception, and the relative dephasing of the beams is because each beam follows a different phase law.
Abstract: The method involves dividing an antenna into a number (n) of adjacent parts. A number of elements of a divided signal are applied to the parts according to a predetermined phase law. On reception, a number of beams are formed simultaneously. Each beam formed has an angular width equal to n times the angular width for the complete antenna. The relative dephasing of the beams is because each beam follows a different law. The beams are displaced to cover the angular domain desired.
01 Jan 1999
TL;DR: The Dutch PHARUS system is a polarimetric active phased array SAR which is capable of performing advanced SAR modes such as spotlight SAR, MTI and Scan SAR, and specialised autofocus techniques, which aim to extract phase behaviour over a coherent integration interval, and over a wide frequency band are investigated.
Abstract: The Dutch PHARUS system is a polarimetric active phased array SAR which is capable of performing advanced SAR modes such as spotlight SAR, MTI and Scan SAR. High resolution can be obtained using the spotlight mode. Although in general the processing for such a mode is well-known for conventional beam steering, electronic beam steering with an active phased array SAR presents particular difficulties. In order to successfully implement the required coherent integration of a long synthetic aperture, the phase behaviour of the antenna as a function of beam steering angle and frequency must be well understood. Another technique, implemented for range resolution improvement, is the use of stepped frequency pulses. Because of the higher total bandwidth involved, the antenna is pushed to its limits in terms of frequency range. The frequency dependence of the antenna has to be well known and compensated in this case. Finally, PHARUS will be used for repeat pass interferometric experiments. In order to obtain coherence between the two passes, the azimuth aspect angle of the two passes must be nearly the same. This necessitates active, real time beam steering, to compensate for aircraft attitude. Again, knowing the antenna phase behaviour is essential in this case. This paper describes the current slate of investigations into these matters. The techniques used to investigate the active antenna phase behaviour are Near-Field antenna measurement, in which the antenna far field pattern is calculated from measurements of the near field, and specialised autofocus techniques, which aim to extract phase behaviour over a coherent integration interval, and over a wide frequency band.
Patent•
26 Jul 2018
TL;DR: In this article, an antenna port switching device and an active antenna unit (AAU) were provided. But the switching module is used for adjusting opposite positions of the first printed circuit board and the second printed circuit boards according to the configuration mode of a radio frequency module.
Abstract: Embodiments of the present invention provide an antenna port switching device and an active antenna unit (AAU) The antenna port switching device of the present invention comprises: a first printed circuit board, a second printed circuit board, and a switching module The first printed circuit board comprises external antenna port groups and internal antenna port groups The external antenna port groups comprise a first external antenna port group and a second external antenna port group The internal antenna port groups comprise a first internal antenna port group and a second internal antenna port group The second printed circuit board comprises a metal microstrip, and is used for communicating the first external antenna port group and the second external antenna port group with corresponding internal antenna port groups, respectively The switching module is used for adjusting opposite positions of the first printed circuit board and the second printed circuit board according to the configuration mode of a radio frequency module The embodiments of the present invention implement an antenna applicable to multiple AAU configurations