16 research outputs found

    Quantum well intersubband photodetectors in focal plane arrays

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    Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 1996.Includes bibliographical references (p. 235-246).by Paul Scott Martin.Ph.D

    High performance CMOS integrated circuits for optical receivers

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    Optical communications is expanding into new applications such as infrared wireless communications; therefore, designing high performance circuits has gained considerable importance. In this dissertation a wide dynamic-range variable-gain transimpedance amplifier (TIA) is introduced. It adopts a regulated cascode (RGC) amplifier and an operational transconductance amplifier (OTA) as the feed forward gain element to control gain and improve the overload of the optical receiver. A fully-differential variable-gain TIA in a 0.35µm CMOS technology is realized. It provides a bit error rate (BER) less than 10-12 for an input current from 6µA-3mA at 3.3V power supply. For the transimpedance gain variation, from 0.1kΩ to 3kΩ, -3dB bandwidth is higher than 1.7GHz for a 0.6pF photodiode capacitance. The power dissipations for the highest and the lowest gains are 8.2mW and 24.9mW respectively. A new technique for designing uniform multistage amplifiers (MA) for high frequency applications is introduced. The proposed method uses the multi-peak bandwidth enhancement technique while it employs identical, simple and inductorless stages. It has several advantages, such as tunability of bandwidth and decreased sensitivity of amplifier stages, to process variations. While all stages of the proposed MA topology are identical, the gain-bandwidth product can be extended several times. Two six-stage amplifiers in a TSMC 0.35µm CMOS process were designed using the proposed topology. Measurements show that the gain can be varied for the first one between 16dB and 44dB within the 0.7-3.2GHz bandwidth and for the second one between 13dB and 44dB within a 1.9-3.7GHz bandwidth with less than 5.2nV/√Hz noise. Although the second amplifier has a higher gain bandwidth product, it consumes more power and occupies a wider area. A technique for capacitance multiplication is utilized to design a tunable loop filter. Current and voltage mode techniques are combined to increase the multiplication factor (M). At a high input dynamic range, M is adjustable and the capacitance multiplier performs linearly at high frequencies. Drain-source voltages of paired transistors are equalized to improve matching in the current mirrors. Measurement of a prototype loop filter IC in a 0.5µm CMOS technology shows 50µA current consumption for M=50. Where 80pF capacitance is employed, the capacitance multiplier realizes an effective capacitance varying from 1.22nF up to 8.5nF

    5 GHz Optical Front End in 0.35um CMOS

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    With the advantages of low cost, low power consumption, high reliability and potential for large scale integration, CMOS monolithically integrated active pixel chips have significant application in optical sensing systems. The optical front end presented in this thesis will have application in Optical Scanning Acoustic Microscope System (O-SAM), which involves a totally non-contact method of acquiring images of the interaction between surface acoustic waves (SAWs) and a solid material to be characterized. In this work, an ultra fast optical front-end using improved regulated cascade scheme is developed based on AMS 0.35mm CMOS technology. The receiver consists of an integrated photodiode, a transimpedance amplifier, a mixer, an IF amplifier and an output buffer. By treating the n-well in standard CMOS technology as a screening terminal to block the slow photo-generated bulk carriers and interdigitizing shallow p+ junctions as the active region, the integrated photodiode operates up to 4.9 GHz with no process modification. Its responsivity was measured to be 0.016 A/W. With multi-inductive-series peaking technique, the improved ReGulated-Cascade (RGC) transimpedance amplifier achieves an experimentally measured -3dB bandwidth of more than 6 GHz and a transimpedance gain of 51 dBW, which is the fastest reported TIA in CMOS 0.35mm technology. The 5 GHz Gilbert cell mixer produces a conversion gain of 11 dB, which greatly minimized the noise contribution from the IF stage. The noise figure and input IIP3 of the mixer were measured to be 15.7 dB and 1.5 dBm, respectively. The IF amplifier and output buffer pick up and further amplify the signal for post processing. The optical front end demonstrates a typical equivalent input noise current of 35 pA=pHz at 5 GHz, and a total transimpedance gain of 83 dB ohm whileconsuming a total current of 40 mA from 3.3 V power supply. The -3 dB bandwidth for the optical front end was measured to be 4.9 GHz. All the prototype chips, including the optical front end, and the individual circuits including the photodiode, TIA, mixer were probe-tested and all the measurements were taken with Anritsu VNA 37397D and Anritsu spectrum analyser MS2721A

    5 GHz Optical Front End in 0.35um CMOS

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    With the advantages of low cost, low power consumption, high reliability and potential for large scale integration, CMOS monolithically integrated active pixel chips have significant application in optical sensing systems. The optical front end presented in this thesis will have application in Optical Scanning Acoustic Microscope System (O-SAM), which involves a totally non-contact method of acquiring images of the interaction between surface acoustic waves (SAWs) and a solid material to be characterized. In this work, an ultra fast optical front-end using improved regulated cascade scheme is developed based on AMS 0.35mm CMOS technology. The receiver consists of an integrated photodiode, a transimpedance amplifier, a mixer, an IF amplifier and an output buffer. By treating the n-well in standard CMOS technology as a screening terminal to block the slow photo-generated bulk carriers and interdigitizing shallow p+ junctions as the active region, the integrated photodiode operates up to 4.9 GHz with no process modification. Its responsivity was measured to be 0.016 A/W. With multi-inductive-series peaking technique, the improved ReGulated-Cascade (RGC) transimpedance amplifier achieves an experimentally measured -3dB bandwidth of more than 6 GHz and a transimpedance gain of 51 dBW, which is the fastest reported TIA in CMOS 0.35mm technology. The 5 GHz Gilbert cell mixer produces a conversion gain of 11 dB, which greatly minimized the noise contribution from the IF stage. The noise figure and input IIP3 of the mixer were measured to be 15.7 dB and 1.5 dBm, respectively. The IF amplifier and output buffer pick up and further amplify the signal for post processing. The optical front end demonstrates a typical equivalent input noise current of 35 pA=pHz at 5 GHz, and a total transimpedance gain of 83 dB ohm whileconsuming a total current of 40 mA from 3.3 V power supply. The -3 dB bandwidth for the optical front end was measured to be 4.9 GHz. All the prototype chips, including the optical front end, and the individual circuits including the photodiode, TIA, mixer were probe-tested and all the measurements were taken with Anritsu VNA 37397D and Anritsu spectrum analyser MS2721A

    The 1992 4th NASA SERC Symposium on VLSI Design

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    Papers from the fourth annual NASA Symposium on VLSI Design, co-sponsored by the IEEE, are presented. Each year this symposium is organized by the NASA Space Engineering Research Center (SERC) at the University of Idaho and is held in conjunction with a quarterly meeting of the NASA Data System Technology Working Group (DSTWG). One task of the DSTWG is to develop new electronic technologies that will meet next generation electronic data system needs. The symposium provides insights into developments in VLSI and digital systems which can be used to increase data systems performance. The NASA SERC is proud to offer, at its fourth symposium on VLSI design, presentations by an outstanding set of individuals from national laboratories, the electronics industry, and universities. These speakers share insights into next generation advances that will serve as a basis for future VLSI design

    Center for Space Microelectronics Technology

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    The 1991 Technical Report of the Jet Propulsion Laboratory Center for Space Microelectronics Technology summarizes the technical accomplishments, publications, presentations, and patents of the Center during the past year. The report lists 193 publications, 211 presentations, and 125 new technology reports and patents

    Center for space microelectronics technology

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    The 1992 Technical Report of the Jet Propulsion Laboratory Center for Space Microelectronics Technology summarizes the technical accomplishments, publications, presentations, and patents of the center during the past year. The report lists 187 publications, 253 presentations, and 111 new technology reports and patents in the areas of solid-state devices, photonics, advanced computing, and custom microcircuits

    Modelling, Analysis and Design of Optimised Electronic Circuits for Visible Light Communication Systems

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    This thesis explores new circuit design techniques and topologies to extend the bandwidth of visible light communication (VLC) transmitters and receivers, by ameliorating the bandwidth-limiting effects of commonly used optoelectronic devices. The thesis contains detailed literature review of transmitter and receiver designs, which inspired two directions of work. The first proposes new designs of optically lossless light emitting diode (LED) bandwidth extension technique that utilises a negative capacitance circuit to offset the diode’s bandwidth-limiting capacitance. The negative capacitance circuit was studied and verified through newly developed mathematical analysis, modelling and experimental demonstration. The bandwidth advantage of the proposed technique was demonstrated through measurements in conjunction with several colour LEDs, demonstrating up to 500% bandwidth extension with no loss of optical power. The second direction of work enhances the bandwidth of VLC receivers through new designs of ultra-low input impedance transimpedance amplifiers (TIAs), designed to be insensitive to the high photodiode capacitances (Cpd) of large area detectors. Moreover, the thesis proposes a new circuit, which modifies the traditional regulated cascode (RGC) circuit to enhance its bandwidth and gain. The modified RGC amplifier efficiently treats significant RGC inherent bandwidth limitations and is shown, through mathematical analysis, modelling and experimental measurements to extend the bandwidth further by up to 200%. The bandwidth advantage of such receivers was demonstrated in measurements, using several large area photodiodes of area up to 600 mm^2, resulting in a substantial bandwidth improvement of up to 1000%, relative to a standard 50 Ω termination. An inherent limitation of large area photodiodes, associated with internal resistive elements, was identified and ameliorated, through the design of negative resistance circuits. Altogether, this research resulted in a set of design methods and practical circuits, which will hopefully contribute to wider adoption of VLC systems and may be applied in areas beyond VLC

    Journal of Telecommunications and Information Technology, 2002, nr 1

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