COMPACT ULTRA-WIDE-BAND BAND-PASS FILTERS WITH ENHANCED PASSBAND AND STOPBAND PERFORMANCES USING THE MATERIAL AND STUBS

摘要

A band pass filter for an ultra wide band is provided to reduce a reflection loss without a change of a total size by attaching a matching circuit to an input/output port. A band pass filter for an ultra wide band includes a pair of symmetrical ladder type inter-digital capacitors(40) and an inductance linear line(50). An input port and an output port are positioned on a micro strip line. A pair of symmetrical ladder type inter-digital capacitors is serially connected between the input port and the output port. The inductance linear line is extended from a pair of symmetrical ladder type inter-digital capacitors. An end part of the inductance linear line is grounded. A size of a pair of symmetrical ladder type inter digital capacitors is smaller than lambdag/4. A stepped impedance matching circuit is coupled in the input port and the output port for reducing a reflection loss of the input port and the output port.