Order High Pass Filter Research Articles

Second Order Low-Pass and High-Pass Filter Designs Using Method of Synthetic Immitance Elements

The paper briefly describes the basics of frequency filter design method using synthetic immittance elements with current conveyors. An introduction of the paper explains the advantages and also disadvantages of using this method. Other chapters briefly introduce a design process of simple second order low-pass and high-pass filter. A theory of current conveyors is discussed too, because they are the basic building blocs of proposed synthetic element and also active frequency filters. Finally, the particular solutions of low-pass and high-pass filters are given and verified by OrCAD PSpice simulations.

Research on Harmonic Suppression and Power Compensation of Aluminum Electrolytic Rectifier

According to analyze damage of current aluminum electrolytic rectifier, one second order high pass filter was presented, which can complete harmonic suppression and power compensation. At the same time, principle and parameters computation method of it were given in the paper. Experiment results proved, it could reduce harmonic currents and increase power factor effectively if the according methods were used to design filter, it is obvious economic effects and good application prospects in the aluminum electrolytic enterprises. With the current power system harmonic pollution becoming serious, its damage is given great concern by the electrical profession. The aluminum electrolytic rectifier is great harmonic source in power system, which output currents to it, and which bright large sum of extra power rate to enterprises according to current power rate metering method[1].Furthermore, it can reduce rectifier units power factor. Accordingly, it is necessary to complete harmonic suppression and reactive power compensation for power system supplying good quality electrical energy. The given company 160KA aluminum electrolytic rectifier was presented for the experiment object in our country in the paper. According to analyzing its structure and parameters, one design method of second order high pass filter was given, which could complete harmonic suppression and power compensation. After the filter was used, it not only could suppress harmonic current, but also could increase power factor to reasonable level so as to reach anticipation effects.

Novel grounded parallel inductance simulators realization using a minimum number of active and passive components

In this paper novel lossless and lossy grounded parallel inductance simulators are reported. All grounded inductor simulator circuits employing only a single DXCCII and three passive components are proposed. The proposed topologies realized all grounded parallel inductance variations. To demonstrate the performance of the presented DXCCII based parallel inductance simulators, we used one of the circuits to construct a third order high-pass filter, a voltage-mode band-pass filter and LC oscillator. Simulation results are given to confirm the theoretical analysis. The proposed DXCCII and its applications are simulated using CMOS 0.35μm technology.

Tone-control circuit and method for conditioning respective frequency bands of an audio signal

An audio tone-control circuit includes 4 th -order low-pass, 4 th -order band-pass, and 4 th -order high-pass filter circuits. The 4 th -order low-pass filter circuit has a first phase response and receives and filters an audio signal and generates a first output signal therefrom. The 4 th -order band-pass filter circuit has a second phase response that is substantially equal to the first phase response and receives and filters the audio signal to generate a second output signal. The 4 th -order high-pass filter circuit has a third phase response substantially equal to the first and second phase responses and receives and filters the audio signal to generate a third output signal. The audio-signal circuit also includes a combining circuit that combines the first, second and third output signals into a combined signal. Furthermore, the filter circuits may be 2 nd -order filter circuits instead of 4 th -order filter circuits.

A multi-port D-R mutator using CCIIs with current followers

A multi-port D-R mutator with new current conveyors (CFCCIIs) as the four-port active element is proposed. Each CFCCII consists of a current follower added to a second-generation current conveyor (CCII). This proposed circuit is a simple configuration using CCIIs, CFCCIIs and grounded capacitances and is applied to higher order high-pass filters. This configuration can realize a superior transmission characteristic, inheriting the characteristic of the conventional LC filter. Since all the passive elements are grounded, the influence of parasitic elements of current conveyors can be reduced with this circuit configuration. As a result, this circuit is considered a suitable configuration for monolithic integration. Results obtained from the SPICE simulations show the realized filters have excellent performance and the circuit is effective.

New CMOS fully differential difference transconductors and application to fully differential filters suitable for VLSI

New CMOS voltage controlled fully differential difference transconductors (FDDT) are presented. The basic structure of the proposed transconductors is based on the current linearization of basic MOS cells in different configurations consisting from two or four NMOS matched transistors operating in the saturation region. The proposed transconductors are used to design fully differential second order lowpass, bandpass and highpass filters suitable for VLSI. PSpice simulation results for the proposed fully differential difference transconductors and their filter applications indicating the linearity range and verifying the analytical results are also given.

A novel low-cost capacitive-sensor interface

This paper describes the design of a new capacitive sensor interface. The interface is based on the use of a novel type of oscillator whose frequency is insensitive to low- and high-frequency interfering signals by the application of a third order high-pass filter and special dither techniques. The fully integrated 0.7 /spl mu/m CMOS circuit shows an inaccuracy of less than 100 aF with respect to a 2 pF reference capacitor over a -30/spl deg/ to +70/spl deg/C temperature range. The applied measurement concept guarantees high stability, high accuracy and a negligible influence of parasitic capacitances without the need for calibration.

Design and analysis of bilinear digital ladder filters

Methods for designing bilinear switched-capacitor (SC) ladder filters are well known. However, they cannot be directly extended to digital filters because of the delay-free loops allowed in SC filters. In the present paper, design methods for low-sensitive bilinearly transformed voltage-current ladder filters are developed. The matrix approach for SC filter design is extended to digital filters, and the delay-free loops are eliminated. Design equations for general order low-pass, high-pass, bandpass, bandstop, and allpass filters are obtained in a simple closed form. The design procedure gives a canonical number of delays and a number of distinct multipliers equal to the number of reactive elements in the prototype. A number of test filters are analyzed with respect to magnitude sensitivity, magnitude response with respect to coefficient quantization, occurrence of limit cycles, stability, quantization noise levels, and structural complexity. The results are compared to wave digital filters (WDF), and cascade-form filters. It is found that bilinear digital ladder filters (BDLF) in most cases perform better than WDFs, while they at the same time have a simpler structure.

Log filtering using gyrators

A general realisation for gyrators applicable to log filters, and ESS filters in general, is proposed. An implementation based on the ‘E-cells’ presented in is given. Its large signal behaviour is shown to be linear by embedding the proposed topology into a first order log filter circuit used to produce a first order highpass filter function in an equivalent way to an R-L filter.

Nullators and Norators simplify Design of RC Active Filters

Equivalent circuit of an ideal operational amplifier using NULLATORS and NORATORS is realised. Further, it is shown how this simplifies the analysis of multiple feedback loop active filter. Design constant K are calculated for second order Butterworth type low pass and high pass filters.