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.

Sensorless Low-Current Start-Up Strategy of 100-kW BLDC Motor With Small Inductance

Abstract: This paper focuses on the start-up strategy of a high-speed 100-kW brushless dc motor with small inductance using a voltage comparator. This paper includes three key technique contributions: 1) determining zero-speed positioning, 2) removing high-frequency disturbances, and 3) optimizing the controller parameters. The sensorless low-current start-up strategy is based on an amplification circuit: a low-pass filter circuit and a signal modulate circuit. The amplification circuit is used to amplify the amplitude of back electromotive force for detecting the rotor position at low speed, the low-pass filter circuit is used to remove high-frequency disturbances, and the signal modulate circuit is used to obtain the rotor position signal. A hysteresis control strategy is proposed against the load disturbance in the start-up stage. Experimental results show that the proposed sensorless start-up strategy can realize a low-current start-up.

Rfid module and rfid device

Abstract: An RFID module includes an RFIC element, a filter circuit, a matching circuit, and a radiating element. The filter circuit and the matching circuit define an RFID device. The filter circuit includes a first inductance element, a second inductance element, and a capacitor. The first inductance element and the second inductance element are of equal inductance, and are strongly magnetically coupled to each other so as to strengthen magnetic fluxes to each other. With this configuration, an RFID module and an RFID device that include a filter circuit to remove harmonic components of the RFIC element but are not large as a whole are constructed.

A widely tunable active RF filter topology

Abstract: An active inductor based bandpass radio-frequency (RF) filter circuit topology is presented that achieves a wide tuning range. Based on the proposed structure, a prototype 2/sup th/-order filter is designed, simulated, and laid out in a 0.18/spl mu/m CMOS process. The center frequency of the filter can be tuned from 880MHz to 3.72GHz. The quality factor of the filter can also be tuned. The filter, including the input and output buffers, consumes between 12 to 26mW from a 1.8V supply and occupies a chip area of 115/spl mu/m /spl times/ 70/spl mu/m.

Two-branch microwave channelized active bandpass filters

Abstract: The realization of small highly selective microwave filters has emerged as a prominent issue in the design of miniaturized high-frequency systems. In this paper, a new way to implement channelized active bandpass filters is presented that deals with the impasse. The concept involves a two-branch configuration, which yields filter circuits that are more compact and offer lower noise figures than earlier three-branch versions, while still retaining all the advantages of channelized feedforward operation. The practicability of the technique is demonstrated with two 10 GHz bandpass filters of different design, whose assessed performance characteristics include signal distortion and noise properties.

Genetically derived filter circuits using preferred value components

Abstract: In the realisation of discrete-component analogue electronic circuits it is common practice, because of costs, to specify passive component values from a set preferred of values. For the design of integrated circuits it can also be desirable to use a standard set of passive component values. For example, to obtain accurate ratio matching of integrated resistors and capacitors by stacking identical unit valued components. The usual design approaches produce circuits in which the permitted component values are assumed to be unrestricted. The circuit is then converted to a practical circuit by simple rounding of the exact component values to the nearest value in the permitted set. Of course, in general the circuit performance realised will differ from the ideal. It may then be necessary to repeat the design with a more stringent specification or to use a more closely spaced set of permitted values, both of which can have cost implications. However if other combinations of permitted values are considered, a better circuit performance may potentially be achieved than that obtained by simple rounding. The difficulty is that in all but trivially simple circuits the space of all feasible combinations to be searched is huge. Genetic algorithms (GAs) can be used to search this space. There the application is to a simple second order active filter specified by its transfer function parameters. The aim of the present contribution is to show that GAs can be successfully applied to more complex filter structures. Moreover the optimal search is carried out directly on the frequency-response template specification rather than on a specified approximating ideal transfer function, thereby avoiding this additional source of approximation. The next section outlines the basic GA and its implementation for the present application. Results are then given for practical filter examples. An all-pole low pass response is considered with template specified by a 1 dB pass band ripple with a pass band edge at 10/sup 5/ rad/sec, and stop band attenuation of -150 dB at a stop band edge of 10/sup 6/ rad/sec. The GA is used to generate both LC ladder structures and the more complex FDNR active RC structures. >