摘要 |
<p>The invention relates to an analog bandpass filter comprising a plurality of LC ladder circuits (1), the response from which is determined by a passband (fpi, fps) and a rejection band (with limits fri and frs). The inventive filter is characterised in that a series of tank circuits (5) is disposed in parallel to the filter charge, the resonance frequencies of said tank circuits coinciding with the lower (fpi) and upper (fps) cut-off frequency of the pass-band of the filter. Furthermore, the filter comprises a control resistor (Rc) which regulates the effect of the tank circuits on the filter. Said structure can be used to compensate the effect of the real limitations of the LC components (1) in order to adjust the response from the analog bandpass filter created with said components to the response from the ideal bandpass filter.</p> |