scispace - formally typeset
Search or ask a question
Topic

Reflective array antenna

About: Reflective array antenna is a research topic. Over the lifetime, 4366 publications have been published within this topic receiving 57884 citations.


Papers
More filters
Journal ArticleDOI
TL;DR: It is demonstrated that an antenna optimized in this way shows a high sensitivity when used for near-field detection of a phantom with dielectric properties representative of muscle tissue.
Abstract: We present an approach to design from scratch planar microwave antennas for the purpose of ultra-wideband (UWB) near-field sensing. Up to about 120 000 design variables associated with square grids on planar substrates are subject to design, and a numerical optimization algorithm decides, after around 200 iterations, for each edge in the grid whether it should consist of metal or a dielectric. The antenna layouts produced with this approach show UWB impedance matching properties and near-field coupling coefficients that are flat over a much wider frequency range than a standard UWB antenna. The properties of the optimized antennas are successfully cross-verified with a commercial software and, for one of the designs, also validated experimentally. We demonstrate that an antenna optimized in this way shows a high sensitivity when used for near-field detection of a phantom with dielectric properties representative of muscle tissue.

47 citations

Journal ArticleDOI
TL;DR: In this paper, a compact pattern reconfigurable dual-antenna array is designed at 2.65 GHz for multiple-input multiple-output (MIMO) terminal applications, such as laptops.
Abstract: In this communication, a compact pattern reconfigurable dual-antenna array is designed at 2.65 GHz for multiple-input multiple-output (MIMO) terminal applications, such as laptops. Each antenna is composed of two layers, i.e., the monopole layer and the planar inverted-F antenna (PIFA) layer. By switching the p-i-n diodes on each layer, its radiation patterns can be varied between conical and boresight patterns. Two such identical antennas are placed side by side on a common ground plane for MIMO application, providing altogether four operating modes. The center-to-center separation between the antennas is 0.25 wavelength, to keep the overall array compact. To facilitate an isolation of above 17 dB over all the modes for this compact array, two decoupling techniques based on the decoupling slits and the shielding wall are effectively combined. The envelope correlation coefficients (ECCs) of the far-field patterns in the four modes are below 0.05 in free space, and below 0.1 for most cases in the indoor and outdoor scenarios. The only exception is the monopole-PIFA mode in the outdoor scenario, but the ECC is still below 0.3 for this case. The measured efficiencies of the antennas are between −1.7 (68%) and −0.7 dB (85%) for all the modes. Therefore, good diversity and MIMO performances are expected for the proposed design.

47 citations

Journal ArticleDOI
TL;DR: In this paper, the reduction of the radar cross section (RCS) of the Vivaldi antenna is achieved by removing a portion of the metal from the radiator and implementing periodic slots adjacent to the radiating edge.
Abstract: In this communication, radar cross section (RCS) reduction of Vivaldi antenna is achieved with structural modifications. This is realized by removing a portion of the metal from the radiator and implementing periodic slots adjacent to the radiating edge. These slots reduce the perpendicular reflections from the radiator, which causes reduction of the monostatic RCS. The proposed Vivaldi antenna operates from 4 to 12 GHz with 10 dB additional RCS reduction when compared with the reference Vivaldi antenna. The prototype is fabricated and its performance is validated using measurements.

47 citations

Journal ArticleDOI
TL;DR: In this article, the design and measurements of a remote frequency identification (RFID) tag built of a graphene-based dipole antenna and a chip operating in the ultra-high frequency (UHF) band in accordance with the EPC Global Class 1 Gen 2 standard is described.
Abstract: This paper describes the design and measurements of a remote frequency identification (RFID) tag built of a graphene-based dipole antenna and a chip operating in the ultrahigh-frequency (UHF) band in accordance with the EPC Global Class 1 Gen 2 standard A custom-designed antenna has been designed first Then, it was used to construct several tags that have been tested with a standard RFID reader to reveal that each one is fully operational, although the interrogation range for the graphene-based circuits has been limited in comparison to copper antennas This can be attributed to increased sheet resistance of a graphene layer and—in the case of tags fabricated on paper—also to significant dielectric losses of the substrate material However, it seems that for applications where the interrogation range is not crucial the novel antenna can be an alternative to much more expensive circuits printed with silver-based inks

47 citations

Proceedings ArticleDOI
29 Dec 2011
TL;DR: In this article, the performance of a number of uniform circular array (UCA) configurations for phased array antennas is compared in the context of adaptive beamforming properties and Signal to Interference Ratio (SIR).
Abstract: This paper compares the performances of a number of uniform circular array (UCA) configurations for phased array antennas. A UCA geometry is targeted due to its symmetrical configuration which enables the phased array antenna to scan azimuthally with minimal changes in its beam width and sidelobe levels. Each UCA configuration consists of 19 isotropic elements. Particle Swarm Optimization (PSO) is used to calculate the complex weights of the antenna array elements in order to adapt the antenna to the changing environments. Comparisons are made in the context of adaptive beamforming properties and Signal to Interference Ratio (SIR). The results obtained suggest that a planar uniform hexagonal array PUHA (1:6:12) is suitable for high resolution applications as its sidelobe levels are the lowest compared to the other geometries.

47 citations


Network Information
Related Topics (5)
Antenna measurement
39.6K papers, 494.4K citations
96% related
Antenna (radio)
208K papers, 1.8M citations
96% related
Dipole antenna
38K papers, 513.8K citations
95% related
Microstrip antenna
43.9K papers, 604.4K citations
94% related
Microstrip
40.1K papers, 468.1K citations
92% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20238
202222
20211
20209
20199
201816