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•
13 Feb 2012TL;DR: In this paper, a transmission method and apparatus utilizing multiple-input and multiple-output (MIMO) precoding based on Distributed Antenna Systems (DASs) are provided.
Abstract: A transmission method and apparatus utilizing Multiple-Input and Multiple-Output (MIMO) precoding based on Distributed Antenna Systems (DASs) are provided. The transmission method includes determining active antenna ports, for a User Equipment (UE) having multiple receive antennas, from among a plurality of Distributed Antenna Ports (DAPs) evenly placed in a service area; assigning a Multiple-Input and Multiple-Output (MIMO) mode to the UE and notifying the UE of the MIMO mode assignment; determining a signal precoding vector on a basis of feedback information for the MIMO mode received from the UE; and precoding a signal using the signal precoding vector and transmitting the precoded signal through the active antenna ports.
15 citations
Patent•
30 Sep 2003
TL;DR: In this paper, an active broad-band reception antenna, in which the internal amplification of the active antenna is lowered if a predetermined signal level is exceeded, and which consists of a passive antenna part having output connectors that are connected with the input connectors of an amplifier circuit.
Abstract: An active broad-band reception antenna, in which the internal amplification of the active antenna is lowered if a predetermined signal level is exceeded, and which consists of a passive antenna part having output connectors that are connected with the input connectors of an amplifier circuit. The input circuit of the amplifier circuit contains a three-pole amplification element with its impedance control connector being connected with the first connector of the passive antenna part, at high frequency. The input admittance of a transformation network having the nature of a low loss filter for low amplitude, high-frequency reception signals, has a counter-coupling and linearizing effect in the high-frequency connection between the source connector of the three-pole amplification element and the second connector of the passive antenna part. The transformation network is loaded with a continuing circuit at its output. There is at least one adjustable electronic element, responsive to a control amplifier connected to the output of the active amplifier for adjustably lowering the reception level, and disposed in the transformation network, so that the input admittance of the transformation network, that has the linearizing effect, is reduced, if there is a reduction of the high-frequency reception signal.
15 citations
TL;DR: In this article, an investigation into using subharmonic injection locking to control the radiated phase or an active patch oscillator is presented, which can result in an improved phase control range over fundamental locking.
Abstract: An investigation into using subharmonic injection locking to control the radiated phase or an active patch oscillator is presented. This technique is an attractive locking method and can result in an improved phase control range over fundamental locking. A significant phase control range >360 degrees is experimentally achieved by using a novel element configuration. Results are described and some potential implementation difficulties are noted. >
15 citations
01 Oct 1994
TL;DR: The extension of the small magnetic dipole source analysis of microstrip line discontinuities to active devices is described, indicating that reduced radiation pattern perturbation will result from the active device being integrated within the periphery of the patch.
Abstract: The current interest in active microstrip antennas has highlighted the need for analysis of the radiation characteristics of such antennas. The paper describes the extension of the small magnetic dipole source analysis of microstrip line discontinuities to active devices. The analysis is then combined with the patch cavity model to form a flexible, approximate analysis suitable for implementation in active antenna computer-aided design packages. Computed results agree well with measurements and show that radiation from the active device and associated matching circuits can be significant. The analysis indicates that reduced radiation pattern perturbation will result from the active device being integrated within the periphery of the patch.
15 citations
TL;DR: In this paper, a novel active integrated conical horn array is presented, where a 95 GHz quasioptically fed mixer integrated with an annular slot ring antenna was used as the basic element of the proposed active system.
Abstract: In this paper, a novel active integrated conical horn array is presented. Specifically, a 95 GHz quasioptically fed mixer integrated with an annular slot ring antenna was used as the basic element of the proposed active system. For efficient reception, a low cost micro-machined conical horn array was fabricated and placed on the top of active elements. A modified nonorthogonal finite-difference time-domain (FDTD) approach was applied for analyzing the basic conical horn antenna and a hybrid matrix manipulation technique for efficient antenna array modeling. The proposed active conical horn antenna array was fabricated and measured. Numerical simulations have verified the design at its distributed stages presenting very good agreement with the experimental data
15 citations