Active antenna

About: Active antenna is a research topic. Over the lifetime, 2246 publications have been published within this topic receiving 26493 citations.

Fixed frequency broadside–endfire beam steerable antennas

Abstract: A novel reconfigurable broadside–endfire microstrip antenna is proposed. The beam steering is achieved by reconfiguring the ground plane. The ground plane can be reconfigured either into a high-impedance surface for broadside radiation or into a surface waveguide for endfire radiation. A DC bias line, not connected to the folded dipole feed in any way, is used to switch the PIN diodes. PIN diodes are soldered on the back of the antenna and have no possibility of interfering with the feed. The proposed antenna is designed to work at the ISM 2.45 GHz band with a combined 2:1 VSWR bandwidth of 110 MHz and a combined radiation coverage of 133° on the H-plane. A 5 V power supply or a 9 V battery can be used to operate the active antenna.

On the wireless charging using active integrated antenna

Abstract: A simple experiment to verify the applicability of self-oscillating active integrated antennas (AIAs) to wireless power transmission system is discussed in this paper. The verification consists of a dual-ring AIA and a half-wave rectifier along with a receiving patch. The spacing between the antennas satisfies the far field condition. According to experiment results, comparable DC voltage to that excited by a commercial RF signal generator can be extracted using this simple antenna pair. It hence verifies the suitability of the AIA as a low-cost solution to serve as the unmodulated continuous-wave (CW) source in wireless charging system.

Mid-symbol duration antenna transition approach for performance enhancement of spatial modulation

Abstract: In this Letter, a novel approach for spatial modulation is presented. The main idea of the proposed approach is to change the active antenna at the middle of the symbol duration. The main advantages of the proposed approach are the improved BER performance and the saving in the number of required transmitter antennas, compared to traditional spatial modulation, generalised spatial modulation, and variable generalised spatial modulation at certain spectral efficiency. The BER performance enhancement of the proposed algorithm is affirmed by Monte-Carlo simulations.

Method for antenna calibration in the near field for active antenna

Abstract: The method according to the invention consists in sampling the elements of a transfer function matrix with the aid of a near-field probe for each radiating source of an active antenna. In order to carry out the measurements, the probe is placed successively in front of each source, and each source is excited in turn in phase opposition, while all the other sources of the array are excited normally. In the case of linear superimposition of radiated fields, the measurements according to the method of the invention make it possible directly to obtain the elements of the transfer function matrix, which comprises the phase and amplitude errors due to the components of the active antenna, as well as the effects of coupling between adjacent sources, which come to modify the theoretical characteristics of the antenna. In the non-linear case, the measurements are repeated and the matrix is obtained by iteration on the basis of a comparison between the theoretical values used to control the antenna, and the measurements of the fields actually obtained. Measurements of individual active modules before assembly can also be made use of according to one variant of the method.

Method and apparatus for testing radio frequency index of active antenna system

Abstract: A method and apparatus for testing a radio frequency index of an active antenna system are provided. In the method, a tested active antenna system is placed in a test cover for performing radio frequency index testing, wherein, the test cover includes an antenna array part and a passive network part, and the antenna array part and the antenna feeder part of the tested active antenna system are the same. The method for testing includes: monomer calibration of the test cover; near-field coupling calibration; and radio frequency index testing. With the above-mentioned method and apparatus for testing the radio frequency index of the active antenna system, the radio frequency index of the active antenna system can be directly and effectively measured without need of adding an extra test interface.