Current radiometric earth and atmospheric sensing systems in the centimeter wavelength range generally employ a directive antenna connected through a single terminal pair to a Dicke receiver. It is shown that this approach does not lend itself to systems with greatly increased spatial resolution. Signal-tonoise considerations relating to antenna efficiency force the introduction of active eleme...

Sensor collision (interference) is studied in a large network of low bit-rate sensors that communicate via backscatter, i.e. modulate the reflection of a common carrier transmitted by a central reader. Closed-form analysis is provided, quantifying sensor collision (interference) in high-density, backscatter sensor networks (BSN), as a function of number of tags and aggregate bandwidth. Analysis...

Although many directive antennas operating in a narrow band of millimeter (mm) waves were reported, e.g., antennas for 60GHz wireless local area network (WLAN), their wideband counterparts are still unpopular. Cavity-backed antennas (CBAs) are widely developed and reported in microwave frequency bands, but handful of literatures can be found about mm-wave CBAs in spite that their many propertie...

This paper presents the utilizing of ferroelectric material on antenna application. There are two different ferroelectric had been used on the proposed antennas which include of Barium Strontium Titanate (BST) and Bismuth Titanate (BiT), suitable for Access Points operating in the WLAN IEEE 802.11 b/g and WiMAX IEEE 802.16 within the range of 2.3 GHz to 2.5 GHz application. BST, which had been ...

BACKGROUND The assessment of electromagnetic field distribution near radiophones and their use warranted an analysis of ther mal exposure hazards and related health effects, based on i.e. numerical calculations of specific energy absorption rate (SAR). MATERIALS AND METHODS The investigation concerned radiophones of conventional and trunked communication systems. Electromagnetic hazards asses...

Fully metallic geodesic lens antennas are popular for millimetre-wave band applications due to their simplicity, robustness and low loss. Here, we report the experimental results of a array antenna, which was specifically designed be additive-manufactured in one single piece using Laser Powder-Bed Fusion (LPBF). LPBF aluminum alloy AlSi10Mg is able produce high conductivity relatively surface r...

There has been a lot of study published in literature on the improvement of the performances of microstrip patch antennas. Most of the solutions proposed in the past were to use an array of several antennas. The particular disadvantage of this method comes from the feeding of each antenna and also from the coupling between each element. Other interesting solutions have then been suggested: the ...

We show that the combined use of radio frequency absorbers and directive antennas can produce significant changes of the radio propagation channel properties along the positions of a virtual array inside a reverberation chamber. A multidimensional characterization of the channel was performed at 40 antenna positions with spacing of 0.233λ at 1 GHz. The average power, the Ricean K-factor, the co...