1,721,059 research outputs found
Multi-Band VCO Based On Distributed VCO And Switched-Capacitors Banks
No full textThe paper introduces a new approach for the design of multi-band distributed VCOs for mobile TLC applications. The techniques exploits the potentialities of a switched-capacitor approach, joint to, the versatility of a distribute VCO. The design procedure is discussed. The measured characteristics of a hybrid prototype are reported, validating the potentialities of the approach
Two-photon interactions at single fluorescent molecule level
No full textSingle-molecule spectroscopy and single-molecule detec-tion are emerging areas that have many applications when combinedwith scanning, imaging, and spectroscopy techniques. We have com-bined a commercial confocal scanning head, to a Ti:sapphire laserand to an inverted microscope, for the detection of single moleculefluorescence of varies dyes by two-photon excitation. We collectedspot images of fluorescent molecules that have been deposited on asubstrate considering both blinking and photobleaching behavior of fluorescent spots. Here, we report data related to two-photon interac-tions that occur with the following fluorescent molecules: Indo-1,Rhodamine 6G, Fluorescein, and Pyrene. The choice of these specificdyes is based upon their wide use in biological and medical applica-tions together with the varying complexity of their chemical structurethat increases from Pyrene to Indo-1. Moreover, we report some dataabout single molecule studies related to denaturation of an enhancedgreen fluorescent protein, GFPmut2, under one photon excitation re-gime, that show a very similar trend to that observed for the alreadymentioned fluorescent molecules
A Novel 2.4GHz High-Resolution and Low-Power Phased Array Transmitter
No full textA new approach to design a low-power high phase resolution phased array transmitter is presented. The proposed approach uses a PLL configuration that is able to perform simultaneously the LO-path phase shifting and the up conversion. A 2.4GHz 7-bit phased array transmitter is reported, with a 0.5° measured worst-case RMS phase error in the band of synthesis. The reported experimental results perfectly match the theoretical ones validating the architecture potentialities
Phase shifter based on DDS-driven offset-PLL
No full textA new topology for phase-shift control in the transmitter module of phased array antennas is introduced. The proposed structure is based on a hybrid DDS-PLL approach. An offset-PLL evolution is proposed in order to preserve phase resolution, along with a maximum phase shift of 360deg. Experimental results obtained by a prototype are reported, validating the architecture potentialitie
Low-power Tx module for high-resolution continuous programmable phase shift
No full textA novel phase shifter topology for digital phased antenna arrays based on a low-power phase control block joint with an innovative PLL design is presented. Experimental results obtained by a prototype are reported validating the architecture capabilitie
Novel IC wideband Distributed Voltage Controlled Oscillator with double tuning for multi-band applications
No full text
A 12-bit track and hold amplifier for giga-sample applications
Full text linkThe paper presents a track-and-hold amplifier (THA), based on the switched emitter follower topology, suitable for emerging receivers architectures and data acquisition systems. The THA exploits four concurrent techniques, all described in the paper, which allow to reduce the hold-mode feedthrough; to attenuate the differential droop rate; to improve the linearity of the input buffer; and to optimize the third order harmonic distortion for RF sampling operation. The effectiveness of this novel approach is demonstrated using a low cost 0.35 μm SiGe technology. The THA core draws about 145 mA from 3.5 V supply. The THA provides a spurious-free dynamic range (SFDR) better than 72 dB when it is used for sampling an incoming signal of 0.9 Vpp centered around 925 MHz at a sampling rate of 0.5 GS/s. The THA allows a max sampling frequency equal to 6 GS/s and a max input frequency equal to 2.5 GHz and provides a SFDR better than 50 dB in all the available working conditions
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