2° order biquad/universal continuous time IF analog active filters type resonant and active full self-compensation techniques to improve the frequency range, the stability and/or the selectivity of the filters with a very low, or as if zero, cost. These techniques are the only ones that can (fully) erase the parasitic poles using a single resistor or an additional operational amplifier with a functionally filtering output; so in several applications the additional manufacturing cost is zero.
These inventions have 2 patent families:

1° Patent Family (publication numbers):
IT1338618 B1 (granted); US7038531 B2 (granted); EP1470640 A1;

2° Patent (Application) Family:
ITMI20031566 A1; US2006197587 A1; EP1665525 A2; CN1875542 A

For SALE or LICENSING===>Contact: cavazzoniroberto@tiscali.it

INTRODUCTION: As known to persons skilled in electronics, filters have an essential role. In fact, starting from a frequency signal, it's necessary to process it and obtain another signal having phase and amplitude according to a predetermined frequency of interest. In the telecommunications field particulary, where high amplification is necessary, a system can become critical if the filtering operation is not adeguate, and the useful information can be lost. Until now analog active filters have had several problems, mainly due the parasitic effects of the amplifiers although many compensation techniques have been studied for. To obviate the problem, usually several filter stages are cascade connected, but this drammatically increases the cost and can make the system unstable, which is clearly unacceptable.

INVENTION: This invention relates to 2° order, 3 base-stages biquad/universal continuous time (CT) analog active filters type resonant and, more particulary, noiseless active full self-compensation techniques to improve the frequency range, the stability and/or the selectivity of the filters themselves with a very low or as if zero cost, overcoming said problems.
These active filters techniques are revolutionary, because they are the only ones in the world that (fully) extend the limited bandwidth of the operational amplifiers employed using, with new direct connections, a single resistor or an additional operational amplifier that has a functionally filtering output, and without destabilizing the filter itself.

EXPERIMENTAL TEST: These filters have been carefully studied, go-between thousands of behaviour analysis done by computer using the P.S.P.I.C.E. simulator software, and testing dozen of prototypes.
Several types of analog CT active filters are available today, someone recently patented by great companies too using low noise balanced operational amplifiers also, but they can’t make use of the “Total Parasitic Voltage Control System” (TPVCS). So, mine is the best product in its category for all the above mentioned reasons.

MARKET PERSPECTIVES: Currently, some international semiconductor/electronics company, is looking forward to use my inventions in an application plan. This product type has good market into U.S.A., Canada, Europe and China.

ACKNOWLEDGMENTS:
-The new self-compensation principle (TPVCS), object of several international patents/patent applications (several going to be granted), has WON 2 Invention Awards at the “National Big Electronics Fear”, Forlì-Italy, and received an interview on RAI TV, state television.
-WINNER of the February's, 2008 Contest. See the "Inventors Hall of Fame":
http://www.ideanextstep.com/inventors_hall_of_fame.php

All the Patents' Official PUBLICATIONS are available at the following link:
http://v3.espacenet.com/results?sf=a&DB=EPODOC&PGS=10&CY=ep&LG=en&ST=adv...