DocumentCode :
1170126
Title :
Active RC filters containing periodically operated switches
Author :
Hirano, Kotaro ; Nishimura, Shotaro
Volume :
19
Issue :
3
fYear :
1972
fDate :
5/1/1972 12:00:00 AM
Firstpage :
253
Lastpage :
260
Abstract :
The state-variable approach to inductorless filters that utilize resistors, capacitors, gyrators, controlled sources or negativeimpedance converters (NIC), and switches suitable for integration is described. By using the state equations of active RC networks in the standard form, it is shown that multiplications of resistances, gyration conductances, transfer coefficients of controlled sources, and NIC in active RC network can be achieved by means of the switching technique. From these results, the relations between the input and the output at signal frequency of active RC filters containing periodically operated switches are derived at the steady state for the case where the switching frequency is much higher than the signal frequency. The results show that the cutoff and the center frequencies of active RC filters are adjustable by changing the ratio of the on duration in a period to the period of switching. The experimental results of low-pass, bandpass, and high-pass filters are shown along with the theoretical curves.
Keywords :
Active filters, RC; Active networks; State-space methods; Switched filters; Active filters; Band pass filters; Capacitors; Equations; Frequency; Gyrators; Radio control; Resistors; Switches; Switching converters;
fLanguage :
English
Journal_Title :
Circuit Theory, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9324
Type :
jour
DOI :
10.1109/TCT.1972.1083445
Filename :
1083445
Link To Document :
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