نتایج جستجو برای: helical antenna

تعداد نتایج: 68840  

2013
Shi Qiang Fu Qing Gong Kong Shao Jun Fang Zhong Bao Wang

A new small, low-profile and light-weight helical antenna element was designed for L-band satellite communications. The novelty of the antenna is that its input impedance matching has been improved by adjusting the copper strip matching stub, while its circular polarization performance has been enhanced by changing the parasitic radiation patch loaded in the front of the antenna. The optimal an...

Journal: :IEEE Transactions on Antennas and Propagation 1984

Journal: :International Journal of Antennas and Propagation 2019

Journal: :Journal of Computer and Communications 2018

2006
Wannipa Yadum Nobuo Nakajima

MIMO is the key technology to improve spectrum efficiency in the wireless communications. However, MIMO may perform poorly as a mobile terminal with a very small antenna. This paper describes an experimental study on the performance of a compact MIMO antenna. In order to improve the performance, a cross polarized configuration was investigated as well as a co-polarized configuration. Experiment...

2017
Stanislav Kovar Hana Urbancokova Jan Valouch Milan Adamek Vaclav Mach

Nowadays, there are high demands on the transmission of visual information between devices. It is expected that the image will be transmitted at high speed and if it is possible at all times. The helical antenna designed in this paper works at the frequency of 5.820GHz for which are suggested standards for signal transmission. It is assumed to insert the product into Unmanned Aerial Vehicles as...

2015
Dmitriy D Karnaushenko Daniil Karnaushenko Denys Makarov Oliver G Schmidt

Smart implants are envisioned to revolutionize personal health care by assessing physiological processes, for example, upon wound healing, and communicating these data to a patient or medical doctor. The compactness of the implants is crucial to minimize discomfort during and after implantation. The key challenge in realizing small-sized smart implants is high-volume costand time-efficient fabr...

2013
Nur A. Husni Mohammad T. Islam Mohammad R. I. Faruque Norbahiah Misran

This paper analyzes and discusses the effect of the electromagnetic absorption by human head against variation of head dielectric properties at 900, 1800 and 1900 MHz. The characteristics of helical antenna and its substrates with variation in human head dielectric properties are simulated by implementing finite-difference time-domain (FDTD) method using CST Microwave studio. The variations in ...

1998
Steven R. Best

Since the first demonstration of wireless technology in 1886 by Heinrich Hertz and its first practical radio application by Guglielmo Marconi in 1901, the antenna has been a key building block in the construction of wireless communications systems. In many instances, the antenna is not considered critical in the initial system design, however, it is the single device that allows RF energy to tr...

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