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nonlinearity
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Nonlinearity in Superconducting Microwave Planar Structures
, M.Sc. Thesis Sharif University of Technology ; Farzaneh, Forouhar (Supervisor) ; Fardmanesh, Mehdi (Co-Advisor)
Abstract
Nowadays superconducting devices and especially high temperature superconductors (HTSs) have found very wide applications in microwave engineering. This technology is raised in the form of planar microwave structures and in the different shapes of superconducting microstrip transmission lines, strip lines and coplanar waveguide (CPW) lines and different kind of applications like resonators, couplers, filters, antennas, etc. Important advantage of these structures is very low loss, small size and high quality factor. However nonlinear behavior of superconducting microwave devices, due to the dependence of the surface impedance on the applied field, limits the power handling capability of...
Design of Radio Frequency CMOS Power Amplifier for Cellular Telephony
, M.Sc. Thesis Sharif University of Technology ; Haj Sadeghi, Khosrow (Supervisor)
Abstract
A Radio Frequency Power Amplifier was designed for IS-95 standard in 0.18μm / 1.8V CMOS technology. In order to increase output voltage swing and protect gate oxide of devices, pseudo-differential cascode topology was exploited. Bondwire inductors with exact modeling were used to tune out parasitic capacitances. A low-pass, L match impedance transformation network, realized using bondwire inductors, was used at output of power amplifier. An impedance transformation network design process was developed which considers the quality factor of inductors, from the first step. Also having examined the nonlinearity phenomena in power amplifiers, a fast simulation or measurement method was proposed...
Bent function and Upper Bounds on the Nonlinearity of Vectorial Functions
, M.Sc. Thesis Sharif University of Technology ; Khazaie, Shahram (Supervisor)
Abstract
the theses is composed of two main parts related to the nonlinearity of vectorial functions. The first part is devoted to maximally nonlinear vectorial function (bent vectorial functions) which contribute to an optimal resistance to both linear and differential attacks on symmetric cryptosystems. They can be used in block ciphers at the cost of additional diffusion-compression-expansion layers, or as building blocks for the construction on substitution boxes (S-boxes) and they are also useful for construction robust codes and algebraic manipulation detection codes. A main issue on bent vectorial bent functions is to characterize bent monomial trace functions leading to a classification of...