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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01 Jun 2019
TL;DR: This paper presents a distributed digital predistortion architecture which separates the adaptation and actuator parts, and can save more than 80% of the DPD FPGA resource in an active antenna system with 64 branches.
Abstract: This paper presents a distributed digital predistortion (DPD) architecture which separates the adaptation and actuator parts. Unlike conventional DPD architectures in which these two parts are usually placed in the same FPGA, the proposed architecture puts the actuator parts into a transceiver chipset which can provide such a function. Compared to conventional DPD architectures, the proposed distributed architecture can save more than 80% of the DPD FPGA resource in an active antenna system with 64 branches.
TL;DR: In this paper, a novel method for beam steering with an active ultra-wideband antenna array is presented for impulse-radio ultra wideband, which consists of four planar Vivaldi antennas in a collinear arrangement.
Abstract: A novel method for beam steering with an active ultra-wideband antenna array is presented for impulse-radio ultra-wideband The antenna array consists of four planar Vivaldi antennas in a collinear arrangement with an impulse generator circuit mounted chip-on-board on each antenna element The beam steering is done by shifting the phase of the control signals triggering the impulse generators In the array arrangement a measured beamwidth of 16° is achieved for an antenna spacing of 4 cm compared to 80° for a single Vivaldi antenna Beam steering is experimentally demonstrated for a steering angle of 30°
Patent•
06 Jun 2012
TL;DR: In this paper, a power supply detection and control circuit consisting of a voltage sampling circuit, a CPU (Central Processing Unit) circuit, and a switch circuit is presented, where the CPU circuit compares two paths of sampling voltage signals and outputs a control signal to the switch circuit to keep the power supply loop to be conducted or cut off, and according to the characteristics of an active antenna or the smart card and a relevant power supply circuit, the sampling resistance parameter for converting a power input current signal into a voltage signal, CPU polling time and CPU prompting messages are regulated to feed back
Abstract: The invention discloses a power supply detection and control circuit, which comprises a voltage sampling circuit, a CPU (Central Processing Unit) circuit and a switch circuit, wherein the voltage sampling circuit and the switch circuit are respectively connected in a power supply loop between a power supply device and an active antenna or a smart card; the output of the switch circuit is connected to the input of the voltage sampling circuit; the voltage sampling circuit converts the passing current signal of the power supply loop into two paths of sampling voltage signals to output the sampling voltage signals to the CPU circuit; the CPU circuit compares two paths of sampling voltage signals; the output of the CPU circuit is connected to the control end of the switch circuit; and the CPU circuit outputs a control signal to the switch circuit to keep the power supply loop to be conducted or cut off. The power supply detection and control circuit has the advantages of simple structure, timely response and low production cost; and according to the characteristics of an active antenna or the smart card and a relevant power supply circuit, a sampling resistance parameter for converting a power supply current signal into a voltage signal, CPU polling time and CPU prompting messages are regulated to feed back the short circuit overcurrent phenomenon, and the active antenna or the smart card can be guaranteed to normally work.
01 Jun 2005
TL;DR: In this article, a frequency reconfigurable antenna using the ON/OFF states of a MEMS (Micro-Electro-Mechanical System) switch is presented, based on a multifrequency planar inverted-F antenna (PIFA), designed with an L-shaped open slot etched upon its main plate.
Abstract: In this paper, a frequency reconfigurable antenna using the ON/OFF states of a MEMS (Micro-Electro-Mechanical System) switch, is presented. This structure is based on a multifrequency planar inverted-F antenna (PIFA), designed with an L-shaped open slot etched upon its main plate. As a proof-of-principle, an ON state RF MEMS switch, modeled by a piece of copper of 1×1mm2, is inserted into the slot to achieve frequency switching (OFF state is modeled without this piece of copper). According to the switch position along the slot, the GSM operating frequency is not detuned while other standards become reconfigurable. To validate our concept, a thermal MEMS switch [1,2], designed and developped at CEA-LETI is used. The MEMS switch is presented and its scattering parameters are measured and compared with simulated results from a simple equivalent RLC circuit. The active device is then inserted in the slot to validate the simulated frequency capabilities of the PIFA.
01 Sep 2009
TL;DR: A new low-cost active antenna for WLAN sensor applications is presented which operates as a transceiver whereby the received coded data signal from the broadside direction is retransmitted over a wide area in other directions.
Abstract: In this paper, A new low-cost active antenna for WLAN sensor applications is presented. The proposed system operates as a transceiver whereby the received coded data signal from the broadside direction is retransmitted over a wide area in other directions. This is performed so that a null response at the main pointing angle is maintained. It is formed by a three elements series array connected to high performance FET-based down-and up-converters. The performance of the proposed architecture is verified using experimental results.