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•
15 Jun 2017
TL;DR: In this article, an active antenna device and a test method for resolving the problem that existing large-scale active antennae cannot be tested by using a traditional test method due to no traditional antenna connectors are presented.
Abstract: Disclosed are an active antenna device and a test method therefor, for resolving the problem that existing large-scale active antennae cannot be tested by using a traditional test method due to no traditional antenna connectors. The active antenna device comprises: a transceiver array, a radio frequency calibration and test distribution network unit, an antenna passive distribution network unit, an antenna array, and S test connectors, wherein the radio frequency calibration and test distribution network unit is connected to the transceiver array through N data channels and M calibration channels respectively and is connected to the test connectors, and the antenna passive distribution network unit is connected to the radio frequency calibration and test distribution network unit through N data channels and is connected to the antenna array through P data channels, N being a positive integer greater than or equal to 1, M being a positive integer greater than or equal to 1, P being a positive integer greater than or equal to 1, and S being a positive integer greater than or equal to 1.
Posted Content•
TL;DR: In this article, the authors characterized the rate achievable in a bidirectional quasi-static link where several user equipments communicate with a massive MIMO base station (BS) in full-digital mode, and the physical size of the antenna array is limited, and there exists a rate constraint on the fronthaul interface connecting the radio head to the digital baseband processing unit.
Abstract: We characterize the rate achievable in a bidirectional quasi-static link where several user equipments communicate with a massive multiple-input multiple-output base station (BS). In the considered setup, the BS operates in full-digital mode, the physical size of the antenna array is limited, and there exists a rate constraint on the fronthaul interface connecting the (possibly remote) radio head to the digital baseband processing unit. Our analysis enables us to determine the optimal resolution of the analog-to-digital and digital-to-analog converters as well as the optimal number of active antenna elements to be used in order to maximize the transmission rate on the bidirectional link, for a given constraint on the outage probability and on the fronthaul rate. We investigate both the case in which perfect channel-state information is available, and the case in which channel-state information is acquired through pilot transmission, and is, hence, imperfect. For the second case, we present a novel rate expression that relies on the generalized mutual-information framework.
01 Jan 2005
TL;DR: In this paper, the design of an active integrated antenna with negative resistance transistor oscillator has been described and a simple but reasonably accurate analysis of oscillation start-up and steady state operating frequency prediction is presented.
Abstract: The design of an active integrated antenna with negative resistance transistor oscillator has been descri- bed. Simple but reasonably accurate analysis of oscillation start-up and steady state operating frequency prediction is presented. The active antenna prototype was manufactured and its operating frequency, EIRP and radiation patterns were measured. Two of these antennas were integrated in active arrays coupled in E- and H-planes. The inter-ele- ment distance in the arrays was optimized to obtain in- phase operation and mutual injection locking. Very good power combining efficiency was measured and beam scan- ning capabilities were demonstrated for both arrays.
01 Jul 2017
TL;DR: In this paper, a plasmonic nano-ring transistor for monolithic terahertz (THz) active antenna has been proposed, which is designed for a 0.12-THz resonance frequency.
Abstract: We report a highly-sensitive plasmonic nano-ring transistor for monolithic terahertz (THz) active antenna. By designing an ultimate asymmetric transistor on a metal-gate structure, more enhanced (180 times) channel charge asymmetry has been obtained in comparison with a bar-type asymmetric transistor of our previous work. In addition, by exploiting ring-type transistor itself as a monolithic circular active antenna, which is designed for a 0.12-THz resonance frequency, we experimentally demonstrated the highly-enhanced responsivity (R V ) > 1 kV/W (x 5) and reduced noise-equivalent power (NEP) < 10 pW/Hz0.5 (x 1/10).
Patent•
17 Dec 2013
TL;DR: In this article, a cellular communication system is described where beam steering techniques are applied to fixed and mobile communication devices to increase system capacity, with capacity optimized for downlink or uplink performance.
Abstract: A cellular communication system is described where beam steering techniques are applied to fixed and mobile communication devices to increase system capacity, with capacity optimized for downlink or uplink performance. A previously described technique wherein the current mode on a single radiator is altered to vary the radiation pattern of the radiator is utilized in an FDD cellular system to generate multiple radiation patterns with low correlation between the patterns. Techniques to restrict or expand the frequency bandwidth of the beam steering technique are described to provide the capability to beam steer at receive frequencies or transmit frequencies only, and techniques are described where beam steering can occur at both transmit and receive frequency bands from a single active antenna system. The capacity per cell in the cellular system can be improved for either downlink or uplink by commanding the fixed or mobile devices to optimize correlation between radiation modes for the downlink or uplink frequencies.