Durum-uzay sentez metodu kullanarak a-sinifi ve fark alici ab sinifi logaritmik ortam süzgeç tasariminda yeni olanaklar

Log-domain filters are a new generation filters and one of the most important class of the current-mode circuit family. The aim of this dissertation is to realize new class-A and differential type class-AB log-domain filters which are systematically derived using state-space synthesis procedure. Several analysis and synthesis methods of log-domain circuits are presented, and the general exponential state-space synthesis method is rearranged and improved in order to design for novel different log-domain filter circuits. State-space synthesis method is a very powerful and efficient approach for the synthesis of log-domain filters. It provides a very general solution for realizing a filter function. Some of the circuits are also designed using both the state-space synthesis method and corresponding block diagram. In this thesis, first-order (class-A, allpass class-AB, multifunction class-A, multifunction class-AB), second-order (two-integrator-loop biquad class-A, notch class-AB, allpass class-AB, universal class-AB), third-order (lowpass class-AB, universal class-AB), fourth-order bandpass class-AB for VHF applications, and fifth-order elliptic lowpass class-AB filter for video frequency applications are proposed. The natural frequency, the quality factor, and gain of the filters can be electronically tuned by changing external currents. The filters are suitable for low voltage/power applications. Only BJTs and grounded capacitors are used, and operated with single power supply. The proposed filters have a greater bandwidth, large dynamic range and lower THD values due to inherently current-mode and realizing linear system with inherently nonlinear circuit building blocks and companding properties. Key Words: Log-domain filters, state-space synthesis method, current-mode circuits, class-A, differential class-AB, companding, low power/voltage filters.