Browsing by Author "Haslett, James W."
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Item Open Access 10-Gb/s 0.13-um CMOS Inductorless Modified-RGC Transimpedance Amplifier(IEEE, 2015-07-17) Taghavi, Mohammad Hossein; Belostotski, Leonid; Haslett, James W.; Ahmadi, PeymanThis paper presents an inductorless 0.13-um CMOS TIA structure that is a modified version of a regulated cascode (RGC) TIA. An immittance converter is incorporated to reduce power consumption while increasing ransimpedance gain. Measured 3-dB bandwidth is 7 GHz, sufficient for 10-Gb/s operation, in the presence of 250 fF capacitance at the TIA input, representative of typical CMOS photodiode capacitance. The transimpedance gain of the single-stage TIA is 50 dB, and the group-delay variation is less than ±19 ps over the 3-dB bandwidth. The circuit occupies an active area of 180um x 90um and consumes 7 mW from a 1.5-V supply. The measured average input-referred current noise of the TIA is 31 pA/sqrt(Hz). Simulations and analysis show that the proposed single-stage TIA architecture is capable of achieving improvement in the transimpedance limit over a single-stage RGC TIA designed for the same data rate and the same input photodiode capacitance. A comparison of measurement results to published TIAs also demonstrates the competitive performance of the proposed TIA in terms of the TIA transimpendance gain, bandwidth, area, and power consumption.Item Open Access A Broadband Variable-Gain Amplifier and a Broadband Self-Calibrated High-Sensitivity Power Detector for the Square Kilometre Array(2014-12-03) Wu, Ge; Belostotski, Leonid; Haslett, James W.The Square Kilometre Array (SKA) is an international project to design and construct the next generation ultra-sensitive radio telescope. Depending on the final configuration, the SKA will require millions of receivers ideally fabricated in a low cost semiconductor process. This thesis presents a study of using CMOS technologies, which are themost common and less expensive semiconductor option, to implement a variable gain amplifier (VGA) with a linear-in-dB performance and an RMS power detector (PD) for a mid-frequency SKA receiver. Two linear-in-dB VGAs were designed and experimentally verified in this work. The first VGA meets most of the SKA specifications except bandwidth and linear-in-dB range. The second VGA uses a bandwidth extension technique and a low threshold voltage transistor to achieve a maximum tunable gain range of 34 dB and the linear-in-dB range of 28.5 dB within ±1 dB error, an upper 3 dB cutoff frequency of 2.1 GHz and a power consumption of 1.1mW. Both S11 and S22 are less than -10 dB from 100 MHz up to 4.2 GHz. This VGA achieved the lowest power consumption among comparable VGAs published to date. A differential broadband self-calibrated RMS PD using the MOSFET square-law characteristics was proposed and experimentally verified in this work. After automatically compensating mismatches between all circuit components by adjusting input transistor bulk voltage, the proposed PD circuit showed the highest sensitivity and lowest power consumption of all PDs published prior to this work. The PD operates over an input power range from -48 dBm to -11 dBm with output voltage offset less than 0.95 dB for the SKA midfrequency range with an input-referred P1dB of -11 dBm, 3 dB bandwidth of 1.8 GHz and power consumption of only 1.2 mW. This PD meets all requirements of the mid-frequency SKA receiver. This power detector was embedded within the receiver and fabricated in a TSMC 65nm CMOS process. Measurement results showed an input power range from -40 dBm to -20 dBm with power consumption of 1.5mW.Item Open Access A CMOS high temperature auto-zeroed amplifier(1994) Finvers, Ivars Gunar; Haslett, James W.A precision operational amplifier has been developed which has input offset voltage and current of less than 15 ?V and 0.6 nA, respectively, over an operating temperature range of 2 5 - 200 °C. Low input offset voltage is maintained across the broad temperature range by using an auto-zeroing architecture. This topology uses two internal amplifiers. One amplifier always remains in the signal path, thereby ensuring continuous time processing of the input signal. The other amplifier cyclically zeros it own off set voltage and then zeros the off set voltage of the main amplifier. The primary difficulty in adapting the auto-zeroing topology for high temperature applications relates to leakage currents. A new input switch topology is presented which significantly reduces the leakage current induced input offset current. Degradation of the offset correction voltage that is stored on the internal sample and hold circuitry is reduced by storing the correction signal differentially, reducing switch leakage by using a donut shaped layout, using large external hold capacitors, and by optimizing the auxiliary signal path gain. A comprehensive theory of the operation of the auto-zeroed amplifier is developed, including optimization for minimum offset, frequency stability, and transient behaviour. Periodically switched netiii work analysis is applied to predict the low frequency noise performance. Design equations are presented which link noise performance and system level parameters such as open loop gain, bandwidth, and clock frequency. Five variations of a high temperature auto-zeroed amplifier are implemented and tested. These include three versions of the auxiliary input stage through which the offset correction voltage is applied. The best performance is achieved using an auxiliary input stage based on a parallel differential pair. The amplifiers are all fabricated in a standard 1.2 ?m N-well CMOS process. General specifications (2 5 - 200 °C) are: operation from a single 5 V supply voltage, power dissipation of 5.5 mW, input common mode range includes the negative supply voltage, a CMRR and PSRR of greater than 92 dB, a slew rate of at least 4.5 V /?S, and a unity gain bandwidth of at least 2.2 MHz.Item Open Access A Comprehensive silicon diode model(1987) Clarke, Edmond Edwin, 1938-; Haslett, James W.Item Open Access A fully integrated CMOS operational floating current conveyor (OFCC) circuit(2009) Elsayed, Fahmi; Haslett, James W.Item Open Access A linearized power amplifier using RF pulse density modulation(2005) Holmes, Damon George; Johnston, Ronald H.; Haslett, James W.Item Open Access A logarithmic amplifier and hilbert transformer for optical single sideband(2005) Holdenried, Christopher Daniel; Haslett, James W.Item Open Access A monolithic CMOS transformer based q-enhanced series-c coupled resonator bandpass filter(2006) Kulyk, Jim Morris; Haslett, James W.Item Open Access A new analysis of charge injection error in analog MOS switches(1998) Aghtar, Saeed; Haslett, James W.Item Open Access A self calibration system for optical sensor arrays(1995) Gupta, Atul Krishna; Haslett, James W.Item Embargo A Three terminal analog building block(1978) Rao, M. K. Narendra; Haslett, James W.Item Open Access An Analog position sensing system(1989) Gonnason, William R.; Haslett, James W.This thesis describes an analog position sensing system which has not been previously reported, to the knowledge of the author. The system offers the advantages of improved resolution and speed compared to presently available position sensors. The position sensing system uses a discrete array of sensors to sample a diffuse light distribution, which forms the system input. An analog network using corrective feedback determines the centroid of the light distribution, and produces an output corresponding to the position of the centroid of the intensity distribution. The network output is shown to be directly related to the intensity centroid, thus providing a means of relating the output to the position of the light source. The theory describing the performance and limitations of the sensing system is developed, and simulations to test the algorithm are described. The network has been verified by a hardware prototype. The design of an integrated implementation based on the hardware and simulation results is also described. Simulation and hardware testing results are presented to illustrate the potential performance of the system. It is hoped that the approach can be extended in future to develop inexpensive integrated sensors for industrial and commercial use.Item Open Access An integrated 2ghz automatically tuned multi-state differential radio frequency cmos bandpass filter(2007) Nakaska, Joshua Keith; Haslett, James W.Item Open Access Bipolar and CMOS controlled sources for simulated impedance filters(1987) Walkey, David Jonathon; Haslett, James W.Item Embargo CCD imager evaluation for scientific applications(1984) Hriskevich, Brian (Robert Brian James); Haslett, James W.Item Embargo Characterization of CCD imagers(1984) Klassen, G. Allan; Haslett, James W.Item Embargo Characterization of MOS bucket brigade devices(1975) Kejariwal, Murari Lal; Haslett, James W.Item Open Access Cmos analog front end circuits for rf and if sampling receivers(2008) Pekau, Holly Evelyn; Haslett, James W.Item Open Access CMOS Analog signal processing for a smart antenna system(1999) Chakravorti, Mark F. J.; Haslett, James W.Item Open Access CMOS programmable gain circuits: amplifiers and current conveyors(2005) Quan, James; Haslett, James W.CJ\IOS programmable gain stages form essential building blocks i11 today's Lclccomm1wicat.iou sys Le ms. For each specific application, there may lie a myriad of poLcnt.ial solnt.ious: however, not all soluLiom; are equally suited Lo solving all problems. Sornc problems may be directly treated with traditional voltage-mode approaches while ot.lier problems may lie more efficiently tackled via less convcnLiomt! currcut-modc methods. In view of such an expansive landscape, the present. work seeks Lo investigate t.wo telecommunication applications and Lhe specific solnt.iuu for each. FirsLly, a LradiLional Programmable Gain Amplifier (PGA) is clcsig11ccl for 11:-:c ui Very J-1.igh-Spccd Digit.al Suli:-:cribcr Loops (VDSL). Wide lm,ndwidLh, low noi:-:c, aml high Ii neariLy arc achicve
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