Off-line channel tuning amplitude slope matched filter architecture

A method for continuously and automatically frequency tuning a variable lobe filter structure (VLFS) to an inserted signal to allow tracking of the inserted signal to match a dynamically changing amplitude slope of a second signal using an offline process for improved interference cancellation system performance, the method comprising:

• a) forming a first broadband RF lobed filter having a quiescent null proximate to and offset above a center frequency of an imaginary broadband RF lobed tuning filter;
• b) forming a second broadband RF lobed filter having a quiescent null proximate to and offset below the center frequency of the imaginary broadband RF lobed tuning filter;
• c) detecting a level of RF energy output from the first broadband RF lobed filter as a first broadband RF lobed filter output;
• d) detecting a level of RF energy output from the second broadband RF lobed filter as a second broadband RF lobed filter output;
• e) calculating an error signal by subtracting the first broadband RF lobed filter output value from the second broadband RF lobed filter output value;
• f) integrating the error signal to generate a control voltage;
• g) dynamically adjusting the delay time T, via the generated control voltage, to control a lobe bandwidth of the first and second broadband RF lobed filters, an imaginary nulling RF lobed filter and the imaginary broadband RF lobed tuning filter;
• h) forming a more narrowband RF lobed filter orthogonal to the imaginary broadband RF lobed nulling filter in its quiescent state,
• i) skewing the narrowband RF filter lobe to implement a corrective amplitude slope of the inserted signal, thereby improving the performance in the improved interference cancellation system;
• and
• (j) repeating steps (a)-(i).