1,720,963 research outputs found
A 750mV 15kHz 1/f noise corner 51dBm IIP2 Direct Conversion Front-end for GSM in 90nm CMOS
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A low-power Ka-band direct conversion receiver employing half-frequency Local Oscillator in 65nm CMOS
No full textA low phase-noise multi-phase LO generator for wide-band demodulators based on reconfigurable sub-harmonic mixers
No full textA complete DVB-T/ATSC tuner analog base-band implemented with a single filtering ADC
No full textA filtering ADC used to implement the complete base-band in a receiver chain is presented. Passive filtering and in-band noise shaping lead to a frequency dependent dynamic range that better fits with the system requirements of a wireless receiver. The 90nm CMOS prototype is embedded in a fully integrated tuner compliant with DVB-T and ATSC standards. For a 6MHz channel bandwidth, the filtering ADC exhibits a frequency dependent dynamic range varying from 75.6dB to 90dB while drawing 30mA from a 1.8V supply
Mixer amplifier and radiofrequency front-end circuit
No full textThe mixer amplifier includes an amplification stage having a current source circuit and a plug filter adapted to modify the current circulating in the current source circuit. The amplification stage and a mixer stage amplify an incoming signal and transpose the frequency of the signal to a predetermined frequency. Resistors pairs measure the imbalance between two branches and have a relatively high value (thus creating a high-pass filter). When the branches are perfectly balanced, the voltage tapped by the non-inverting terminal of the operational amplifier A is zero. During an imbalance, this voltage rises. The output of the amplifier drives the TNP transistor T9, causing current to flow into branches to solicit the transistors T7 or T8 of the current source circuits and thus return the two branches to balance. Accordingly, a balance is maintained between the two branches by providing a feedback within the mixer amplifier
A 24 GHz Subharmonic Direct Conversion Receiver in 65 nm CMOS
No full textScaled CMOS proves to be suitable for the design of transceiver ICs at micro- and millimeter-waves. The effort is presently toward compact and low-power solutions in view of integrating several transceivers on the same chip enabling phased array systems. In this paper we present a 24 GHz receiver, based on a subharmonic direct conversion architecture, designed in a 65 nm node. The local oscillator takes advantage of the half frequency operation proving significantly lower power consumption when compared to conventional solutions running at received frequency. Stacked switches for subharmonic down-conversion are passive to save voltage room, current driven and loaded by a transresistance amplifier. Optimum biasing of the switches allows maximizing linearity while saving power in the baseband. The integrated LNA matching network is the bottleneck toward low sensitivities. The LNA design trades-off power consumption, gain and sensitivity. Detailed insights into implementation issues, critical in a single-ended topology where both forward and return signal paths have to be supported, are provided. The chip consumes 78 mW and occupies 1.4 mm2 of active area. Experiments show: 30.5 dB gain, 6.7 dB NF, -13 dBm IIP3
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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