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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08 Sep 1988
TL;DR: In this paper, two types of active antenna elements have been investigated, one using a microstrip antenna with an active device mounted directly on the antenna, and the other using an active devices coupled to a micro-strip patch antenna through an aperture.
Abstract: Two types of active antenna elements have been investigated. One type uses a microstrip antenna with an active device mounted directly on the antenna. The other uses an active device coupled to a microstrip patch antenna through an aperture. Microstrip active antenna elements and two-element arrays have been demonstrated for both types of circuits. Injection locking of the antenna elements has been achieved through space and mutual coupling. The circuit Q-factor was calculated based on the locking gain and locking bandwidth. The power outputs from two elements have been successfully combined in free space with a combining efficiency of over 90 percent. An analytical method based upon the aperture coupling theory and the derivation of S-parameter matrix has been developed for modeling a microstrip line coupled to a microstrip patch antenna using a circular coupling aperture. The results should have many applications in low cost active arrays, active transmitters, and spatial power combiners.
Patent•
01 May 2020
TL;DR: In this article, a single Beidou positioning navigation mark based on global low-orbit satellite communication is proposed, which is used for uploading and issuing of navigation mark wireless data, the communication range is widened, and the navigation mark communication safety is improved.
Abstract: The invention provides a single Beidou positioning navigation mark based on global low-orbit satellite communication. The single Beidou positioning navigation mark specifically comprises a low-orbit satellite communication module, a single Beidou positioning module and a main control module, the single Beidou positioning module is used for navigation mark positioning and comprises a single Beidouactive antenna, a single Beidou antenna short-circuit protection module and a Beidou radio frequency signal receiving module, and the single Beidou active antenna is connected with the Beidou radio frequency signal receiving module through the single Beidou antenna short-circuit protection module; the low-orbit satellite communication module comprises a low-orbit satellite communication module, adata processing unit, a receiving antenna and a transmitting antenna. and is used for communication. The low-orbit satellite communication module and the single Beidou positioning module are electrically connected with the main control module. The system has the advantages that Beidou satellite positioning and low-orbit satellite communication are adopted to complete uploading and issuing of navigation mark wireless data, the navigation mark communication range is widened, and the navigation mark communication safety is improved.
20 Aug 1984
TL;DR: It is highlighted that at frequencies greater than 20 GHz, the transition from the MMIC device to other transmission media must be an accurate RF match and it is proposed that the RF match is sufficiently critical to include the transition as part of the delivered MMIC package.
Abstract: Two different aspects of active antenna array design were investigated. The transition between monolithic microwave integrated circuits and rectangular waveguides was studied along with crosstalk in multiconductor transmission lines. The boundary value problem associated with a discontinuity in a microstrip line is formulated. This entailed, as a first step, the derivation of the propagating as well as evanescent modes of a microstrip line. The solution is derived to a simple discontinuity problem: change in width of the center strip. As for the multiconductor transmission line problem. A computer algorithm was developed for computing the crosstalk noise from the signal to the sense lines. The computation is based on the assumption that these lines are terminated in passive loads.
TL;DR: In this paper, the authors used an existing antenna system consisting of a 2-axis gimbal structure driven by stepping motor and a 3-axis vibratory rate gyroscope to control the base attitude.
Abstract: Satellite communications are utilized widely fields -navigations, broadcast and scientific Recently mobile communications and satellite broadcast are developing remarkably And the active antenna pointing sysem is required so that we may communicate with satellite in transportation, such as sail boat, truck and car In this case, we can assume that the antenna base receives perturbation of a high frequency, and we must construct a compact antenna control system with high response In this research, we use an existing antenna system consisting of a 2-axis gimbal structure driven by stepping motor and a 3-axis vibratory rate gyroscope to control the base attitude The antenna system is used to track a Japanese broadcast satellite in geostationary orbit We propose intellectual satellite position search system with feedback control using AGC level and feedforward control using gyro sensor to correct various errors This papers discusses the 2-axis gimbal structure, sensor system, control algorithm, and experimental result