Parasitic insensitive programmable biquadratic pulse slimming technique
US5235540A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 26, 1990 |
| Grant date | Aug 10, 1993 |
| Priority date | — |
| Expiry date | Apr 26, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H11/0433
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A filter circuit with improved performance characteristics. A biquadratic transconductance-C filter includes a differentiator in the feed forward path of the input signal to compensate for the non-ideal operation of the transconductance elements and to simplify the performance requirements of a variable gain amplifier also in the feed forward path. The variable gain amplifier and feed forward technique are used to create two programmable magnitude, opposite sign zeros on the real axis, whose effect on the incoming data signal results in variable pulse slimming. The addition of a differentiator in the feed forward path eliminates the effect of the output admittance of the transconductance elements on the filter's group delay. The differentiator acts as a first order, high pass filter. The frequency of the differentiator is controlled so that the input signal is attenuated before it is provided to the variable gain amplifier. This reduces the dynamic range requirements of the variable gain amplifier without affecting group delay requirements.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.