Patent ID: 6678511
Filing Date: 2004-01-13
Classification: H03H

Abstract:
A pass band flatness correction circuit for correcting a pass band flatness of a main band pass filter including a first ripple of a first shape in a pass band transfer characteristic for use in a band pass filter system, the pass band flatness correction circuit comprising:a complementary band pass filter having a pass band transfer characteristic producing a counter-ripple of a reverse shape to the first ripple with respect to an input signal, for flattening the whole pass band transfer characteristic of the band pass filter system; an amplifier circuit installed between the main band pass filter and the complementary band pass filter, for amplifying the input signal into a desired gain value; and a first attenuator circuit installed in the rear end of the complementary band pass filter, and having an attenuation characteristic with respect to the input signal in order to enhance a reflective loss characteristic.