نتایج جستجو برای: helical antenna
تعداد نتایج: 68840 فیلتر نتایج به سال:
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...
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...
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...
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...
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 ...
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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