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.

Niobium Tunable Microwave Filter

Abstract: A superconductor bandpass filter with tunable central frequency in the range of 2-3.5 GHz has been implemented using superconducting quantum interference devices (SQUIDs). The filter is designed using two pi-network resonators connected by a transmission line. Both resonators have a SQUID inductor with a tuning range of 65-200 pH, controlled by current magnetically coupled to the SQUIDs. Over a frequency tunability of 1.5 GHz, the filter has a mid-band insertion loss of 0.5-3.0 dB and corresponding maximum unloaded quality factor of 40. Due to the presence of active elements, tunability of the filter depends on the power of the microwave signal. A maximum power of -52 dBm corresponds to a frequency tuning range of 15%. Spectral measurements by controlling the central frequency of the filter with variable pulsewidth shows that the filter can be tuned at a rate of 120 GHz/mus.

Unbalanced saw filter

Abstract: An unbalanced surface acoustic wave (SAW) resonator-filter is achieved by using a predetermined length of unbalanced transmission line to define a ground potential and permit two SAW resonators and such transmission line to function together as an unbalanced filter.

First-order memristor–capacitor filter circuits employing hp memristor

Abstract: The memristor has drawn the worldwide attention since it has been discovered at HP laboratory on 1 May 2008. Since then many researchers are taking efforts to find its applications in various areas. In this paper, we study the filter characteristics of first-order low pass and high pass filters employing memristor with a capacitor. The paper provides a comparative analysis between low pass and high pass filter circuits that utilizing ordinary resistor or memristor with a capacitor. The theoretical analyzes are verified with SPICE simulation results using a memristor SPICE model with nonlinear dopant drift and MATLAB environment. The effect of change of the input frequency and initial resistance value of memristor on the cut-off frequencies of the presented low pass and high pass filters are investigated. The memory effect of memristor is represented by simulation results.

Surface acoustic wave filters in ZnO-SiO/sub 2/-Si layered structures

Abstract: The monolithic integration of SAW (surface acoustic wave) devices in a ZnO-SiO/sub 2/-Si layered structure with high-frequency electronic circuitry has been demonstrated. The high-resolution technology for the fabrication of the aluminum interdigital pattern-electron beam lithography, bilayer masking, and dry etching-is explained and illustrated with SEM (scanning electron microscope) photographs. Experimental results on a SAW delay line, a SAW transversal filter, and a SAW resonator filter show the feasibility of obtaining on-chip selectivity with SAW filters. A passivation of the sputtered, piezoelectric ZnO layer has been realized with a thin silicon nitride layer, resulting in an increased stability of the frequency response of the SAW device. A single-chip FM upconversion radio receiver with an on-chip SAW filter is discussed. >

A Combined System of Shunt Passive and Series Active Filters

Abstract: A combined system of shunt passive and small rated series active filters has already been proposed by the authors. The operating principle and steady compensation characteristics have been presented also. The combined system can greatly reduce problems of using only shunt passive or shunt active filters and is suitable for harmonic compensation for large VA rated loads in power systems, because the required VA rating of the series active filter used here is considerably smaller than that of a conventional shunt active filter.In steady states, the combined system behaves like an ideal compensator, because the extraction of the harmonics easy. However, some loads such as cycloconverters fluctuate with rapid speed and cannot be regarded as steady loads. It is difficult for a conventional shunt passive filter to compensate for these fluctuating loads because they generate various frequency harmonics. So it is necessary to discuss transient compensation characteristics of the combined system when it is applied to compensation for fluctuating loads.In this paper, focusing on transient states, stability and compensation characteristics of the combined system are analyzed and discussed theoretically and experimentally in detail. The stable and unstable regions of the combined system and the problems faced by improving transient compensation characteristics are revealed. Then, to improve transient characteristics of the system, a new control method is proposed, and the validity is experimentally demonstrated.