In this paper we describe an European initiative aiming to establish a broadband Very High Frequency (VHF) aeronautical communications system based on a multi-carrier technology and demonstrate its benefits to the aeronautical community, together with its technological fundamentals. The European research project B-VHF (“Broadband VHF Aeronautical Communications System based on Multi-Carrier Tec...

The viral haemorrhagic fevers (VHF) are a growing public health threat in the Eastern Mediterranean Region. Nearly all of them are of zoonotic origin. VHF often cause outbreaks with high fatalities and, except for yellow fever, currently there are no specific treatment or vaccination options available. In response to this growing threat, the Regional Office for the Eastern Mediterranean of the ...

Technical investigations suggest that DRM+ is a suitable candidate for the transition from analogue FM to digital broadcasting in VHF band II (87.5 108.0 MHz) in Europe [2]. Unfortunately, there are mainly three major problems to solve: 1. VHF band II is historically defined for the use of analogue FM sound broadcasting, and, it is – as such – extensively used in Europe; 2. the lack of agreed c...

U radu je provedena analiza postojećeg širokopojasnog i alternativnog uskopojasnog komunikacijskog sustava pomorskih VHF radiotelefonskih komunikacija, zasnovanih na simulacijskom modelu. Alternativni sustav predložen je od strane ITU organizacije kao jedno od mogućih rješenja problema nedostatka komunikacijskih kanala u pomorskom VHF području. Pomoću računalnih simulacijskih modela ispitan je ...

The method of superposing the standing waves is the idea to generate VHF excited plasmas with excellent uniformity for large area processing. To get such plasmas, we generate two standing waves on the electrode, control the places of their own antinodes, and then, we superpose them. By using this method, VHF pure hydrogen plasmas are produced for various conditions. According to the photographs...

A VHF (30MHz-300MHz) band digitally programmable low noise amplifier (LNA) has been implemented with a 0.25um standard CMOS process for VHF CMMB mobile TV tuners. Utilizing a T-match input network, input matching of more than a decade bandwidth is achieved across all gain settings. Adopting the multiple gated technique, gain flatness enhancement and capacitor reuse etc., the proposed LNA demons...

This article deals with OFDM transmission associated with turbo codes, in order to realize a software radio modem with several waveforms. Except for the frequency transposition, we show that all the functions can be implemented as software. This modem is adapted for HF, VHF and UHF transmission, depending on the chosen waveform. Simulations and tests in real condition achieve a bit error rate o...

A square-law harmonic-rejection mixer (SL-HRM) driven by a sine local oscillator (LO) is proposed for wideband and tunable rejection of all LO harmonics. The key performances including the gain, noise figure (NF), input-referred third-order intercept point (IIP3), and harmonic rejection ratio (HRR) with respect to the amplitude and purity of the sine-LO are analyzed. In the circuit level, the S...

Traditional neuropsychology employs visual half-field (VHF) experiments to assess cerebral language dominance. This approach is based on the assumption that left cerebral dominance for language leads to faster and more accurate recognition of words in the right visual half-field (RVF) than in the left visual half-field (LVF) during tachistoscopic presentation. Information in the RVF is directly...

Abst ract:-The South African Sythetic Aperture Radar System (SASAR) was conceived of as a fully polarimetric, multifrequency, airborne SAR. System design work was carried out at the Radar Remote Sensing Group of the Department of Electrical Engineering, University of Cape Town, starting in 1993. Construction of flight hardware was contracted out to Industry and on board integration was given to...