M.W.P. Strandberg. / 3668776 Archives / Reprinted from Physical review, v. 106, p. 617-620, May 15, 1957. "June 26, 1959"--Cover. / Army Signal Corps Contract DA36-039-sc-78108. Dept. of the Army Task 3-99-20-001 and Project 3-99-00-000.

Benjamin J. Leon. / 3668602 Archives / Based on a thesis, M.I.T. Dept. of Electrical Engineering, April 15, 1959. "June 5, 1959." Also published as Group report 46-59, Lincoln Laboratory, M.I.T., April 6, 1959. / Bibliography: p. 52. / DA36-039-sc-78108. Task 3-99-20-001 and Project 3-99-00-000.

[by] Samuel J. Mason. / "June 10, 1954." / Bibliography: p. 8. / Army Signal Corps Contract No. DA36-039 sc-42607, Project 132B. Dept. of the Army Project No. 3-99-12-022.

John G. Linvill. / "July 7, 1950." / Bibliography: p. 61. / Army Signal Corps Contract No. W36-039-sc-32037 Project No. 102B Dept. of the Army Project No. 3-99-10-022

Thesis (Ph.D.)--University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (April 26, 2007) Vita. Includes bibliographical references.

Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2006. / Includes bibliographical references. Also available in electronic version.

Biopotential signals are important to physicians for diagnosing medical conditions in patients. Traditionally, biopotentials are acquired using contact electrodes together with instrumentation amplifiers (INAs). The biopotentials are generally weak and in the presence of stronger common mode signals. The INA thus needs to have very good Common Mode Rejection Ratio (CMRR) to amplify the weak biopotential while rejecting the stronger common mode interferers. Opamp based INAs with a resistor-capacitor feedback are suitable for acquiring biopotentials with low power and low noise performance. However, CMRR of such INA topologies is typically very poor. In the presented research, a technique is proposed for improving the CMRR of opamp based INAs in RC feedback configurations by dynamically matching input and feedback capacitor pairs. Two instrumentation amplifiers (one fully differential and the other fully balanced fully symmetric) are designed with the proposed dynamic element matching scheme. Post layout simulation results show that with 1 percent mismatch between the limiting capacitor pairs, CMRR is improved to above 150dB when the proposed dynamic element matching scheme is used. The INAs draw about 10uA of quiescent current from a 1.5 dual power supply source. The input referred noise of the INAs is less than 3uV/sqrt(Hz).

This thesis expounds on the application of Doherty Power Amplifiers (DPA) along with baseband Digital PreDistortion (DPD) techniques to tackle the antagonistic demands of high power efficiency and linearity imposed by modern communications. Memoryless modeling is firstly introduced and its limitations when dealing with PAs driven with realistic devices. Therefore, electrical memory effects are explored in greater detail and a mathematical model showing the relation between the various harmonic components in the output and how they can re-mix back into the fundamental band is developed. The importance of the output bias network in the reduction of memory effects is highlighted. A memory polynomial (MP) based DPD is shown to be a good solution for the linearization of wideband DPA which exhibit strong memory effects. To further improve this solution, the complexity of the MP-DPD is reduced. For that, the even-order terms in the MP branches were first removed. Then, the PA memory effects theory was used to further reduce the number of coefficients of the MP-DPD by decreasing the nonlinearity orders in the different branches individually. These two steps allowed for a reduction of the number of coefficients to almost one-third and the conditioning number by three orders of magnitude while maintaining the same linearization capability. This substantially alleviates the requirements on the digital signal processors and the time needed to construct and implement the MP-DPD in real environment. Experimental validation carried out using a 400 Watt DPA, driven with 4-Carrier WCDMA signal, showed excellent linearization capability by achieving an ACPR of better than 50 dBc with a power efficiency of better than 42.4%. Despite this, the depth of the memory effects in the DPA was still significant. While an effort was made to reduce further the memory effects, the discrepancy between the simulated behavior of the DPA and that observed in simulation was significant. In an attempt to rule out the DPA structure as the cause of the discrepancy between the measured results and the behavior predicted in simulation, a single branch class AB PA was designed using the transistor model. The PA behavior was well predicted when driven with a Continuous Wave (CW) signal, however the simulated and measured behavior differed greatly when the PA was driven by a two tone signal. This rendered the desired reduction of the memory effects impossible at the design stage.

Measurements are important to specify and verify properties for components, modules and systems. The specifications for a certain figure of merit are usually given in a numerical value or a two dimensional plot. However, there are some devices, like power amplifiers with certain figure of merits that depends on two or more working conditions, requiring a three dimensional plot. This thesis presents a measurement method including graphical user interface of three parameters gain, efficiency and distortion when two-tone or WCDMA signals are used as an input to the PA.

This thesis expounds on the application of Doherty Power Amplifiers (DPA) along with baseband Digital PreDistortion (DPD) techniques to tackle the antagonistic demands of high power efficiency and linearity imposed by modern communications. Memoryless modeling is firstly introduced and its limitations when dealing with PAs driven with realistic devices. Therefore, electrical memory effects are explored in greater detail and a mathematical model showing the relation between the various harmonic components in the output and how they can re-mix back into the fundamental band is developed. The importance of the output bias network in the reduction of memory effects is highlighted. A memory polynomial (MP) based DPD is shown to be a good solution for the linearization of wideband DPA which exhibit strong memory effects. To further improve this solution, the complexity of the MP-DPD is reduced. For that, the even-order terms in the MP branches were first removed. Then, the PA memory effects theory was used to further reduce the number of coefficients of the MP-DPD by decreasing the nonlinearity orders in the different branches individually. These two steps allowed for a reduction of the number of coefficients to almost one-third and the conditioning number by three orders of magnitude while maintaining the same linearization capability. This substantially alleviates the requirements on the digital signal processors and the time needed to construct and implement the MP-DPD in real environment. Experimental validation carried out using a 400 Watt DPA, driven with 4-Carrier WCDMA signal, showed excellent linearization capability by achieving an ACPR of better than 50 dBc with a power efficiency of better than 42.4%. Despite this, the depth of the memory effects in the DPA was still significant. While an effort was made to reduce further the memory effects, the discrepancy between the simulated behavior of the DPA and that observed in simulation was significant. In an attempt to rule out the DPA structure as the cause of the discrepancy between the measured results and the behavior predicted in simulation, a single branch class AB PA was designed using the transistor model. The PA behavior was well predicted when driven with a Continuous Wave (CW) signal, however the simulated and measured behavior differed greatly when the PA was driven by a two tone signal. This rendered the desired reduction of the memory effects impossible at the design stage.