The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Orthogonal transmission toward N undesired receivers via conventional digital beamforming techniques requires at minimum (N + 1) active transmit antennas. As the radio frequency (RF) complexity increases linearly with the number of active antennas, orthogonal transmit precoding becomes impractical for simple user terminals. The paper proposes an alternative solution utilizing a single-radio reactance-assisted...
This paper describes a low-power/low-voltage CMOS wireless interface (CMOS-WiI) at 5.7 GHz with dry electrodes for congnitive networks. The electrodes are 4 X4 microtip arrays and acquire electroencephalogram (EEG) signals in key- points for processing. The CMOS-WiI was fabricated in a UMC 0.18 μm RF CMOS process and its total power consumption is 23 mW with a voltage-supply of only 1.5 V. The carrier...
This paper describes effects of different frequencies on RSSI measurements and proposes how to increase distance measurement accuracy by using these effects as a new method. RSSI values depend on communication frequency and distance between receiver and transmitter. Electromagnetic signals' free space path loss value is related with their frequency. By using different frequencies, distinct RSSI values...
Passive sensor networks can achieve accurate detection of target under complex environment. In order to adapt to different communication demands of sensor networks in different environments, this paper designed and implemented a wireless and wired mixed communication module, that is, a communication system combined short-distance wireless communication based on radio frequency technology with broadband...
Supporting sensor application over wireless sensor node (WSN) is more challenging than over any other sensor due to the absence of a convenient way to maintenance the sensor node, especially in changing of energy source (batteries). In this paper, we solve this problem by using the ambient energy source (solar), design the efficient power conversion, and low-power consumption in WSN system. Some modifications...
System lifetime of wireless sensor networks (WSN) is inversely proportional to the energy consumed by critically energy-constrained sensor nodes during RF transmission. In that regard, modulated backscattering (MB) is a promising design choice, in which sensor nodes send their data just by switching their antenna impedance and reflecting the incident signal coming from an RF source. Hence, wireless...
An ultra low power 400 MHz 128 kbps-FSK RF transceiver SoC which consumes less than 2 mA from a 1 V supply was implemented in a 0.18 mum CMOS technology for wireless medical applications and applied to a wireless hearing aid communication system, a new generation of hearing aid device. The transceiver was implemented fully differentially and directly matched to a non-50ohm miniaturized dipole antenna...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.