Patent ID: 7555082

Claim:
A continuously tunable linear phase filter having a ground connection, comprising: at least one three-terminal Bessel filter, each of said at least one filter having: an input terminal for receiving a signal, an output terminal for delivering a signal, and a control terminal for receiving a control voltage, each of said terminals being in signal communication with each other; and a varactor in signal communication with each of said terminals and said ground, said varactor being responsive to said control voltage at said control terminal; wherein the capacitance of said varactor is continuously adjustable in response to a change in said control voltage at said control terminal, thereby enabling continuous tuning of said continuously tunable linear phase filter in response to said control voltage; wherein said control voltage is responsive to a known data rate, and further comprising for each of said at least one filter: a first signal path disposed between said input terminal and said output terminal, said first signal path having a first interposed communication point; a second signal path disposed between said first interposed communication point and said ground, said second signal path having a second interposed communication point; and a third signal path disposed between said second interposed communication point and said control terminal, said varactor being disposed in said second signal path between said second interposed communication point and said ground; wherein said control voltage is received at said control terminal for adjusting the capacitance of said varactor, thereby enabling continuous tuning said continuously tunable linear phase filter in response to said known data rate, and further comprising: a control system in signal communication with said control terminal, said control system having a memory containing at least one of a lookup table and a function defining a control voltage level responsive to said known data rate; wherein said control system controls said control voltage at said control terminal in response to the output of at least one of said lookup table and said function.