Typescript (photocopy). / Digitized by Kansas Correctional Industries / Department: Electrical and Computer Engineering.

Thesis (B.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1978. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / B.S.

The demand for broadband wireless communication is growing rapidly, requiring more spectrum resources. However, spectrum usage is inefficient today because different frequency bands are allocated for different communication standards and most of the bands are not highly occupied. Cognitive radio systems with dynamic spectrum access improve spectrum efficiency, but they require wideband tunable receiver hardware. In such a system, a preselect filter is required for the RF receiver front end, because an out-of-band (OB) interferer can block the front end or cause distortion, desensitizing the receiver. In a conventional solution, off-chip passive filters, such as surface-acoustic-wave (SAW) filters, are used to reject the OB interferer. However, such passive filters are hardly tunable, have large area, and are very expensive. On-chip, high-selectivity, linearly tunable RF filters are, therefore, a hot topic in RF front-end research. Switched-capacitor (SC) RF filters, such as N-path filters, feature good linearity and tunability, making them good candidates for tunable RF filters. However, N-path filters have some drawbacks: notably, a poor harmonic response and limited close-by blocker tolerance. This thesis presents the design and implementation of several interferer-tolerant receivers based on SC technology. We present an RF receiver with a harmonic-rejecting N-path filter to improve the harmonic response of the N-path bandpass filter. It features tunable narrowband filtering and high attenuation of the third- and fifth-order LO harmonics at the LNA output, which improves the blocker tolerance at LO harmonics. The 0.2-1 GHz RF receiver is implemented in a 65 nm CMOS process. The blocker 1 dB compression point (B1dB) is -2.4 dBm at a 20 MHz offset, and remains high at the third- and fifth-order LO harmonics. The LNA’s reverse isolation helps keep the LO emission below -90 dBm. A two-stage harmonic-rejection approach offers a > 51 dB harmonic-rejection ratio at the third- and fifth-order LO harmonics without calibration. To improve tolerance for close-by blockers, we further present an SC RF receiver achieving high-order, tunable, highly linear RF filtering. We implement RF input impedance matching, N-path filtering, high-order discrete-time infinite-impulse response (IIR) filtering and downconversion using only switches and capacitors in a 0.1-0.7 GHz prototype with tunable center frequency, programmable filter order, and very high tolerance for OB blockers. The 40 nm CMOS receiver consumes 38.5-76.5mA, achieves 40 dB gain, 24 dBm OB IIP3, 14.7 dBm B1dB for a 30MHz blocker offset, 6.8-9.7 dB noise figure, and > 66dB calibrated harmonic rejection ratio. The key drawback of our earlier SC receiver is the relatively high theoretical lower limit of the noise figure. To improve the noise performance, we developed a 0.1-0.6 GHz chopping SC RF receiver with an integrated blocker detector. We achieve RF impedance matching, high-order OB interferer filtering, and flicker-noise chopping with passive SC circuits only. The 34-80 mW 65 nm receiver achieves 35 dB gain, 4.6-9 dB NF, 31 dBm OB-IIP3, and 15 dBm B1dB. The 0.2 mW integrated blocker detector detects large OB blockers with only a 1 us response time. The filter order can be adapted to blocker power with the blocker detector.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1982. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Vita. / Includes bibliographical references. / by David Michael Papurt. / Ph.D.

Photocopy of typescript. / Digitized by Kansas Correctional Industries

Elie J. Baghdady. / "September 24, 1956." "This report is based on a thesis submitted to the Department of Electrical Engineering, M.I.T., May 16, 1956, in partial fulfillment of the requirements for the degree of Doctor of Science." / Bibliography: p. 106. / Army Signal Corps Contract DA36-039-sc-64637 Dept. of the Army Task 3-99-06-108 Project 3-99-00-100

J. Granlund. / "January 20, 1949." / Bibliography: p. 79. / Army Signal Corps Contract No. W36-039-sc-32037 Project No. 102B. Dept. of the Army Project No. 3-99-10-022.

T.P. Cheatham, Jr. and W.G. Tuller. / "January 20, 1947." / Includes bibliographical references.

Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Yucel Altunbasak; Committee Member: Brani Vidakovic; Committee Member: Ghassan AlRegib; Committee Member: James Hamblen; Committee Member: Russ Mersereau. Part of the SMARTech Electronic Thesis and Dissertation Collection.

published_or_final_version / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy