Two-pole notch filter

A tunable two-pole passive notch filter circuit for attenuating select frequencies of a multi-frequency CATV signal, comprising:

• an input for receiving a multi-frequency CATV signal;
• an output for transmitting a portion of the multi-frequency CATV signal;
• and
• a filter network for attenuating a band of frequencies from said multi-frequency signal, said filter network comprising three branches A, B, and C, wherein branch A comprises an inductor, branch B comprises an adjustable tank circuit, and branch C comprises an adjustable electrical resonator connected to at least one of the input or the output, and wherein branch A and branch B are connected in parallel and are arranged in series connection bete the output and a second inductor, said second inductor arranged in series between the input and branches A and B.

A tunable two-pole passive notch filter circuit, comprising:

• an input;
• an output;
• an adjustable tank circuit arranged in series connection between said input and said output;
• a fourth inductor ranged in parallel with said adjustable tank circuit, and in series connection between said input and said output;
• and
• an adjustable resonant circuit arranged in series correction between said input and said output.