105 research outputs found
The Differential Pair as a Triangle-Sine Wave Converter
R~/ RÃ bstract-The performance of a differential pair with emitter degeneration as a triangle-sine wave converter is analyzed. Equations describing the circuit operation are derived and solved both analytically and by computer. This allows selection of operating conditions for optimum performance such that total harmonic distortion as low as 0.2 percent "-has been measured. -vEE (a
A 4.3 GHz BiCMOS VCO with multiple 360° variable phase outputs using the vector sum method
A 4.3 GHz voltage controlled oscillator (VCO)
with multiple independently tunable phase outputs is presented.
The VCO is realized by coupling two LC oscillators
together in order to obtain quadrature signals and is tunable
between 4.12 and 4.74 GHz. The variable phase outputs
are achieved by varying the amplitudes of the in-phase and
quadrature signals independently and then combining these
signals together. By using multiple Gilbert cells as variable
gain amplifiers (VGAs), multiple tunable phase outputs are
achieved with the use of only one quadrature VCO. The
VGAs are controlled using a custom non-linear digital-toanalog
converter. The entire circuit is designed using a
3.3 V SiGe BiCMOS process. A maximum phase noise of
-108.17 dBc/Hz was measured over the entire tuning
range at a 1 MHz offset. The outputs of the VCO can be
used as local oscillators that achieve phase shifting during
radio frequency up or down conversion.Armscor S. A. Ltd and the
Business Unit: Defence, Peace, Safety and Security (DPSS), Council
for Scientific and Industrial Research (CSIR), South Africa.http://www.springerlink.com/content/0925-1030ai201
Childhood bullying, paranoid thinking, and the misappraisal of social threat: trouble at school
Background:Experiences of bullying predict the development of paranoia in school-age adolescents. While many instances of psychotic phenomena are transitory, maintained victimization can lead to increasingly distressing paranoid thinking. Furthermore, paranoid thinkers perceive threat in neutral social stimuli and are vigilant for environmental risk.
Aims:The present paper investigated the association between different forms of bullying and paranoid thinking, and the extent to which school-age paranoid thinkers overestimate threat in interpersonal situations.
Methods: Two hundred and thirty participants, aged between eleven and fourteen, were recruited from one secondary school in the UK. Participants completed a series of questionnaires hosted on the Bristol Online Survey tool. All data were collected in a classroom setting in quiet and standardized conditions.
Results: A significant and positive relationship was found between experiences of bullying and paranoid thinking: greater severity of bullying predicted more distressing paranoid thinking. Further, paranoid thinking mediated the relationship between bullying and overestimation of threat in neutral social stimuli.
Conclusion: Exposure to bullying is associated with distressing paranoid thinking and subsequent misappraisal of threat. As paranoid thinkers experience real and overestimated threat, the phenomena may persist
Hierarchical Top-Down Design of Analog Sensor Interfaces: From System-Level
The complete application of a hierarchical top-down design methodology to analog sensor interface front-ends is presented: from system-level specifications down to implementation in silicon, including high-level synthesis, analog block generation and layout generation
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