Electronic filter

About: Electronic filter is a research topic. Over the lifetime, 13207 publications have been published within this topic receiving 93063 citations. The topic is also known as: filter.

All-pass filters using DDCC- and MOSFET-based electronic resistor

Abstract: The main motivation in this paper is to draw attention to the tunability and input-signal amplitude limitations when a nonlinear device is used as a resistor. For this purpose, two first-order all-pass filters are proposed using differential difference current conveyor (DDCC), a capacitor and a resistor without element-matching restriction. These all-pass filter circuits can be made electronically tunable with electronic resistors. Tunability and input-signal amplitude limitations of the proposed circuits due to the operational restrictions of the electronic resistors are examined. PSPICE simulations confirm the validity and the practical utility of the proposed circuits. Copyright © 2010 John Wiley & Sons, Ltd. (The main motivation in this paper is to draw attention to the tunability and input-signal amplitude limitations when a nonlinear device is used as a resistor. For this purpose, two first-order all-pass filters are proposed using differential difference current conveyor (DDCC), a capacitor and a resistor without element-matching restriction.)

Electrical filter with multiple filter sections

Abstract: An electrical filter having first and second filter sections with respective sets of electrical filter components. These sets of electrical filter components include primary tuning coils which are arranged parallel to a reference axis. An electrical isolation shield is disposed on a reference plane between the first and second filter sections for electrically isolating the sections from one another, the reference plane being orthogonal to the reference axis. The unique configuration of the filter sections allows for the filter sections to be independently tuned while being physically and electrically isolated from one another. The filter sections are then coupled to one another both physically and electrically subsequent to the tuning operation.

Steady-State Stability of Current-Mode Active-Clamp ZVS DC–DC Converters

Abstract: Active-clamp dc-dc converters are pulsewidth-modulated converters having two switches featuring zero-voltage switching at frequencies beyond 100 kHz. Generalized equivalent circuits valid for steady-state and dynamic performance have been proposed for the family of active-clamp converters. The active-clamp converter is analyzed for its dynamic behavior under current control in this paper. The steady-state stability analysis is presented. On account of the lossless damping inherent in the active-clamp converters, it appears that the stability region in the current-controlled active-clamp converters get extended for duty ratios, a little greater than 0.5 unlike in conventional hard-switched converters. The conventional graphical approach fails to assess the stability of current-controlled active-clamp converters, due to the coupling between the filter inductor current and resonant inductor current. An analysis that takes into account the presence of the resonant elements is presented to establish the condition for stability. This method correctly predicts the stability of the current-controlled active-clamp converters. A simple expression for the maximum duty cycle for subharmonic-free operation is obtained. The results are verified experimentally.

A practical design for insensitive RC-active filters

Abstract: A systematic RC -active network synthesis procedure for the realization of second-order transfer functions is proposed. The realization employs three operational amplifiers and no isolation amplifiers are necessary. The sensitivity of the resulting networks to passive element variations has been found to be low. The sensitivity to variations in the active elements has been made very low. A design is given in which tuning can be achieved by trimming only resistors. The design is particularly attractive for high- Q realizations. The stability properties and the influence of the finite bandwidth of the amplifiers are examined. The proposed realization has been compared with those of Kerwin, Huelsman, and Newcomb, of Tarmi and Ghausi, and of Thomas, and found to offer several attractive features as compared to these realizations. The design procedure was used to obtain a sixth-order elliptic bandpass filter. Experimental results show close agreement between theory and practice. Further, these results indicate that these realizations are insensitive to temperature and power supply variations.

Method and apparatus for measuring on-wafer lumped capacitances in integrated circuits

Abstract: A novel test structure is described which can be used to accurately measure on-wafer impedances. For example, accurate measurements of the parasitic capacitances inside active devices such as Field Effect Transistors or the capacitance of interconnect lines with either the substrate or with each other can be made. The test technique involves frequency sweep S-parameter power measurements made in the range of 50 MHz to about 20 GHz. One or more identical copies of the DUT are connected on the wafer with one or more on-wafer inductances which are usually lumped, to form a two port circuit. The circuit is essentially a filter operating in the frequency range of 50 MHz to 20 GHz. Although filter circuits are normally designed to provide a flat response in the pass and stop bands, with as sharp a skirt as possible, the objective in designing this test circuit is to design a filter response with sharp inflection points that are uniquely dependent on the reactances that comprise the filter circuit. The primary focus during design is to pre-estimate the impedance (e.g. capacitance) of the DUT, and to design the on-wafer inductances used in the circuit such that the frequency response has sharp peaks and valleys, which are easily identified from measurement. In this way the frequencies of the peaks and valleys can be accurately measured. The measured frequency response is then compared to a model of the circuit.