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This paper presents a technique to reduce the noise figure of a passive mixer-first receiver front-end. By using lower than 50Ω switch resistance in the current-mode passive mixer and introducing a positive feedback from baseband to the RF-input, it can be well matched close to fLO while achieving a noise figure below 3dB, which is otherwise a fundamental limit. A quadrature front-end prototype fo
Measurement aspects on a digital beamforming transmitter are addressed. A calibration and steering procedure for the beamforming transmitter is implemented in LabView. After calibration any beam direction can be achieved within a few clock cycles by switching in a digital control word. A reference horn antenna is built to characterize the transmitter and achieves an S11 less than -8 dB in the freq
Drawing on results from a survey made at three local social forums held in Sweden, and interviews with activists taking part in the “co-ordination group” of one of these local forums (and to some extent interviews with Swedish local forum activists that visited the World Social Forum 2007 in Nairobi, Kenya), this paper focus on the transnational and the global dimension of activism within the glob
Major threats to biodiversity and ecosystem persistence are fragmentation of habitats and declining population sizes. For conservation biologists to understand the consequences of declining populations for the long term persistence and recovery of species worldwide, it is important to know and understand the underlying causes of potential threats, such as the depletion of genetic diversity, which
