Tunable balanced loss compensation in an electronic filter
The invention provides a system for providing tunable balanced loss compensation in an electronic filter. Tunable balanced loss compensation is provided by using cross-connected balanced transconductors and self-connected balanced transconductors. The cross-connected balanced transconductors and the self-connected transconductors compensate the unbalanced loss across the electronic filter. The self-connected balanced transconductors compensate the balanced loss across the electronic filter. Further, the cross-connected and the self-connected balanced transconductors are tunable by adjusting the values of their transconductances, thereby providing tunable balanced loss compensation.
1 . A system for providing loss compensation in an electronic filter, the system comprising:
a first set of transconductors, the first set of transconductors comprising at least two balanced transconductors, the at least two balanced tranconductors being cross-connected with each other, the at least two cross-connected balanced tranconductors being connected across balanced input and output ports of the electronic filter; and
a second set of transconductors, the second set of transconductors comprising at least two balanced transconductors, the at least two balanced tranconductors being self-connected, the at least two self-connected balanced tranconductors being connected between two terminals of balanced input and output ports of the electronic filter;
wherein the at least two self-connected balanced tranconductors compensate the balanced resistive loss across the electronic filter and the at least two cross-connected balanced tranconductors and the at least two self-connected balanced tranconductors compensate the unbalanced resistive loss across the electronic filter.
2 . The system of claim 1 wherein the first set of transconductors and the second set of transconductors are tunable.
3 . The system of claim 1 wherein positive inputs of the at least two self-connected balanced transconductors are connected to positive outputs of the at least two self-connected balanced transconductors and negative inputs of the at least two self-connected balanced transconductors are connected to negative outputs of the at least two self-connected balanced transconductors.
4 . The system of claim 1 wherein the loss compensation by the first set of balanced transconductors and the second set of self-connected balanced transconductors in the electronic filter is balanced.
5 . The system of claim 1 wherein the at least two cross-connected balanced transconductors and the at least two self-connected balanced transconductors comprise at least one cross-coupled pair of transistors.
6 . The system of claim 1 wherein the electronic filter comprises at least one LC filter.
7 . The system of claim 6 wherein the LC filter further comprises one or more inductors and one or more varactor diodes connected to each other.
8 . An IF filter in a double conversion TV tuner utilizing the system of claim 1.