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A Low-noise Instrumentation Amplifier for Neural Signal Sensing and a Low-power Implantable Bladder Pressure Monitor SystemLiou, Jian-Sing 11 July 2007 (has links)
The thesis is composed of two topics : a low-noise instru-mentation amplifier (IA) for neural signal sensing and a low-power implantable bladder pressure monitor SOC (system-on-chip).
A low-noise instrumentation amplifier for bio-medical appli-cations is proposed in the first topic. It is designed for sampling vague neural signals thanks to its high gain, high CMRR in a pre-defined bandwidth.
A low-power implantable bladder pressure monitor system is presented in the next topic. The system contains several parts : a commercial pressure sensor, an IA, an analog to digital converter (ADC), a parallel to serial converter (PtoS), an RF transmitter and a sleep controller. The IA with 1-atm canceling is designed for high resolution and linearity in the pre-defined bladder pressure range. For low power and low speed applications, a successive approximation ADC (SA ADC) is employed in the system. A clear flag is added to the PtoS to enhance reliability. Our chip saves a great portion of power to extend the processing time owing to the novel sleep controller.
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Design And Fabrication Of A High Gain, Broadband Microwave Limiting Amplifier ModuleKilic, Hasan Huseyin 01 September 2011 (has links) (PDF)
Microwave limiting amplifiers are the key components of Instantaneous Frequency Measurement (IFM) systems. Limiting amplifiers provide constant output power level in a wide input dynamic range and over a broad frequency band. Moreover, limiting amplifiers are high gain devices that are used to bring very low input power levels to a constant output power level. Besides, limiting amplifiers are required to provide minimum small signal gain ripple in order not to reduce the sensitivity of the IFM system over the operating frequency band.
In this thesis work, a high gain, medium power, 2-18 GHz limiting amplifier module is designed, simulated, fabricated and measured. First, a 3-stage cascaded amplifier with 27 dB small signal gain is designed and fabricated. The 3-stage amplifier is composed of a novel cascaded combination of negative feedback and distributed amplifiers that provides the minimum small signal gain ripple and satisfactory input and output return losses inside 2-18 GHz frequency band. Then, the designed two 3-stage amplifiers and one 4-stage amplifier are cascaded to constitute a limiting amplifier module with minimum 80 dB small signal gain. The designed 10-stage limiting amplifier module also includes an analog voltage controllable attenuator to be used for compensating the gain variations resulting from temperature changes. The fabricated 10-stage limiting amplifier module provides 20 +/- 1.2 dBm output power level and excellent small signal gain flatness, +/- 2.2 dB, over 2-18 GHz frequency range.
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Effect of Nonlinear Amplifiers of Transmitters in the CDMA System Using Offset-QPSKSawada, Manabu, Katayama, Masaaki, Ogawa, Akira 07 1900 (has links)
No description available.
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Development of IS-95 CDMA RF Transceiver Including a Power Amplifier MMIC DesignWang, Shi-Ming 04 July 2001 (has links)
Abstract¡G
This thesis was consisted of two parts. Part 1 introduced the procedure for designing the RF transceiver module in an IS-95 CDMA system using link budget analysis. Part 2 was focused on a CDMA power amplifier integrated circuit design for Personal Communication Service (PCS) applications. The design procedure was introduced in detail and implemented in MMIC for using GaAs HBT foundry provided by the GCS Ltd.. The designed linear gain, output 1dB compression point and power added efficiency (PAE) are above 30 dB, 27 dBm and 36.7% respectively under a single supply voltage of 3.4 V with the help of a diode linearizer. Harmonic components were suppressed more than 26 dB without use of any filters in the output. The adjacent channel power ratio (ACPR) and the VSWR of input port are below -45 dBc and 2 respectively.
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In-Service Monitoring Technique of DWDM Systems Using Optical Time-Domain ReflectometerKuo, I-Yu 17 June 2002 (has links)
Dense wavelength-division multiplexing (DWDM) technology are the provide solutions to increase the capacity of network. With the growth of using the OADM in DWDM system, it is more and more important to research the fault-locating fiber-link in-service supervisory technique for enhance the system reliability. Optical Time Domain Reflectometer (OTDR) is a popular tool to offer an in-service fault-locating of fiber link in fiber-optic transmission systems. But in the DWDM network, this technique is never be used for in-service supervisory application on the system. Are different OADM structures will affect the in-service OTDR monitoring? Since OTDR operates with high peak powers, the stimulated Raman scattering (SRS) effect in the conventional transmission fiber gives rise to power depletion of the data signal, and may degrade the bit-error-rate (BER) performance.
In this work, we investigate the in-service 1.65-£gm OTDR monitoring supported FBG-based OADM structures. We improved FBG sandwiched between a pair of three-port optical circulator and multi-port optical circulator (MOC) FBG-based OADM to support OTDR monitoring, and research the technique of in-service OTDR monitoring for FBG-based, MZ-FBG based OADM system. The system bit-error-rate due to the OTDR monitoring a 10-Gb/s long (> 80 km) distance fiber link is examined. Negligible system power penalty, due to the OTDR monitoring, of both structures in 10 Gb/s dense wavelength division multiplexing (DWDM) link is achieved. That is mean the system with OTDR monitoring should have the in-service fault-location monitoring capability to enhance network reliability. We also investigate the in-service OTDR 1.65-£gm OTDR monitoring on the distributed Raman application system.
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Radio-Frequency Integrated-Circuit Design of Image-Reject Downconverter and Variable-Gain Amplifier for Wireless CommunicationsPu, Ta-Chun 24 July 2002 (has links)
This thesis presents a 2.4GHz image-reject downconverter fabricated in TSMC 0.25 1P5M CMOS process. The integrated active filter can not only filter out the image signal, but also reduce noise figure degraded by parasitic capacitance in the circuit. The differential LC oscillator fabricated in TSMC 0.35 1P4M CMOS process has properties of low phase noise and wide frequency turning range. Finally, a variable gain amplifier implemented in GCS GaAs HBT process was designed using signal summing architecture. The architecture is advantageous to reducing noise, distortion and increasing operating frequency. This thesis has studied what cause the difference between measurement and simulation for better performance in the future design.
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InGaAlAs/InP Semiconductor Optical Amplifier Structures Grown by Molecular Beam EpitaxyTsai, Yao-Tsong 26 June 2003 (has links)
The work of this thesis includes the growth of TE polarization and polarization insensitive semiconductor optical amplifier structures by molecular beam epitaxy. The former is suited to fabricate the SOA and laser of the emitter, the latter is suited to fabricate the SOA of the repeater and receiver. The materials of InAl(1)As, InGa(1)Al(2)As and InGa(2)As were used to be the cladding layer, SCH layer and quantum well(QW), respectively.
The first kind of our SOA structures is for 1.55-£gm TE polarization. The materials of InGa(1)As and InGa(2)As were used to be QW and sub-well, respectively. The second kind of our SOA structures is for 1.55-£gm polarization insensitive. To get polarization insensitive characteristics we use tensile strained InGa(3)As material and add two very thin compressive strain layers, InGa(1)As, in QWs to be sub-wells to mostly confine hh1 state. It has the effect of reducing red shift on the e1-hh1 transition and help to partially balance the strain in QW before the thickness of the tensile strained InGa(3)As exceeds one half of the critical layer thickness. These two kinds of structures include three QWs with modulation doping. It can reduce transparency current and noise figure and increase the saturation output power of SOA with the n-type modulation doping.
We had successfully grown the polarization insensitive SOA structure for 1.52-£gm. The wavelength of TE polarization SOA structures we grew were at 1.45(µm) and 1.47(µm) and there were somewhat differences between the designed and grown. We can increase the PL efficiency after rapid thermal annealing at 550¢J for 30(s)~45(s).
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Design and Implementation of High-Efficiency 2.4 GHz Class-E Power Amplifier MMICs and ModulesChu, Chien-Cheng 10 July 2003 (has links)
This thesis consists of two parts. Part 1 introduces the characteristics of Class E power amplifier. Part 2 is focused on the implementation of Class E power amplifier for 2.4GHz Bluetooth applications. The design procedure follows the theory of class E power amplifier, and is implemented in MMICs and modules. For MMICs, the GaAs HBT foundry services are provided by the GCTC Ltd. and WIN Ltd.. Under single supply voltage of 3.3V and the output power of 20dBm, two designed MMICs have gain 23dB and 11dB, and power added efficiency (PAE) 57% and 72%, respectively. For Hybrid modules, RF transistors are provided by the Filtronic Ltd.. Under the same supply voltage of 3.3V, the measured output power, gain, and power added efficiency are 20 dBm, 25dB, and 75% respectively. Compared with the other types of power amplifiers on the market, Class E power amplifier has higher power added efficiency, and thus can increase the using time of communication system.
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CMOS front-end amplifier for broadband DTV tunerZhang, Guang 29 August 2005 (has links)
In this work, the design of a CMOS broadband low noise amplifier with inherent high
performance single-to-differential conversion is presented. These characteristics are
driven by the double quadrature single conversion digital television tuner which requires
accurately balanced differential signals to perform its function and to improve image
rejection.
A three-stage amplifier is designed to satisfy several requirements of front-end circuits at
the same time. The resistive shunt-feedback topology is adopted to implement a
single-ended broadband low-noise amplifier as the first stage. The second stage is an
on-chip single-to-differential converter, which employs a novel method to improve its
balancing performance. A fully differential buffer capable of driving heavy loads is used
as the third stage to further suppress the phase and magnitude errors of output
differential signals.
Fabricated in 0.35??m TSMC standard CMOS technology, the designed broadband
front-end amplifier manages to limit the phase error to within ??1.5?? and magnitude error
??0.75dB over 50~850 MHz frequency range, with 16dB gain and a noise figure of 4dB.
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The Study and Fabrication of Ultra-broadband Optical Amplifier Based on Cr4+:YAG Double-clad Crystal FiberZhuo, Wen-Jun 03 July 2008 (has links)
Abstract
The maximum capacity of an optical fiber transmission system is more than doubled every year to cater the fast-growing communication need. The technology breakthrough in dry fiber fabrication opens the possibility for fiber bandwidth from 1.3 um to 1.6 um. The fast increasing demand of communication capacity results in the emergence of wavelength division multiplexing (WDM) technology, which results in the need for ultra-broadband optical amplifier. Cr4+:YAG has a strong spontaneous emission spectrum covers from 1.3 um to 1.6 um. In addition, its absorption spectrum is between 0.9 um to 1.2 um, which matches with the pumping source in current erbium doped optical amplifier. Such fiber is, therefore, eminently suitable for optical amplifier applications.
In this thesis, we introduce the development of ultra-broadband optical amplifier using the double-clad Cr4+:YAG crystal fiber, which is grown by the laser heated pedestal growth (LHPG) technique. With the butt-coupling method, the insertion loss decreases to 2.0 dB ~ 2.9 dB in a SMF-Cr4+:YAG DCF-SMF configuration at signal wavelength from 1.26 to 1.64 um. A gross gain of 3.2 dB is demonstrated at 0.7 W bi-directional pump power at present. Moreover, theoretical models and numerical simulations have been developed to find out a better method for experiments. Numerical simulation indicates that the pump ESA will seriously impede the development of optical amplifier using the double-clad Cr4+:YAG crystal fiber.
In the future, in order to reduce pump ESA we attempt to use cladding pump scheme instead of core pump scheme and to choose pump wavelength at 925 nm instead of 1064 nm,. At the same time, we will also try to grow crystal fiber of smaller core diameter and to extend its length to improve gain performance.
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