Inverse Class E amplifier and oscillator phase noise characteristics

This paper gives the first experimental characterisation of the phase noise response of the recently introduced Inverse Class E topology when operated as an amplifier and then as an oscillator. The results indicate that in amplifier and oscillator modes of operation conversion efficiencies of 64%, and 42% respectively are available, and that the excess PM noise added as a consequence of saturated Class E operation results in about a 10 dB increase in PM over that expected from a small-signal Class A amplifier operating at much lower efficiency. Inverse Class E phase transfer dependence on device drain bias and flicker noise are presented in order to show, respectively, that the Inverse Class E amplifier and oscillator follow the trends predicted by conventional phase noise theory. © 2007 EuMA.

MODULATED BACKSCATTER MICROWAVE SECURITY SENSOR

A system capable of deployment as a microwave security sensor which can automatically reject background clutter is presented. The principle of operation is based on analog homodyne detection using 1. Q single side-band down conversion of an AM backscattered modulating signal envelope. A demonstrator is presented which operates with a carrier frequency of 2 GHz and 500 KHz backscattered signal. When deployed in a multipath rich open plan office environment the S/N ratio obtained at the detection output was better than 20 dB at 20 in range with 20 dBm EIRP in a 2 MHz detection bandwidth despite the presence of time varying and static clutter. (C) 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2492-2495, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24636

Self-aligning wireless link using modulated backscatter

A self-tracking (aligning) radio communications system based on the principle of modulated backscatter detection is presented here. Using amplitude-modulated backscatter from a co-operating target, a modified IQ demodulation scheme is used to reproduce automatically and in real time both the received and conjugate of the received phase of an incoming signal. The phase conjugated demodulated IF signal can have incoming backscattered data removed and new data are inserted before being up-converted using IQ single side-band generation so that retro-directive re-transmission can be made to occur. In the absence of the backscattered modulation signal, no phase conjugation and hence no retro-directed re-transmission can occur. The system reported is therefore inherently self-authenticating a facility not readily available from previously reported retro-directive self-tracking systems. © 2010 © The Institution of Engineering and Technology.

Is it painful or not?:Discriminant validity of the Behavioral Indicators of Infant Pain (BIIP) scale

To evaluate the ability of the Behavioral Indicators of Infant Pain (BIIP) scale to discriminate between skin-breaking and nonskin breaking procedures, and to identify sensitized pain responses in preterm infants in the neonatal intensive care unit (NICU).