Harmonic spurious signal suppression filter
The present invention is to provide a harmonic spurious signal suppression filter, which comprises microstrip lines disposed on a printed circuit board of a wireless network product, wherein one end of a microstrip input end is perpendicularly connected to one end of a first microstrip line, one end of a microstrip output end is perpendicularly connected to one end of a fourth microstrip line, the first and fourth microstrip lines are interwovenly arranged in an interdigital finger form, a second microstrip line is extended from both the microstrip input and output ends, and each end of the second microstrip line corresponding to the location of the first and fourth microstrip lines is connected to a third microstrip line of a meandering shape.
1. A harmonic spurious signal suppression filter fabricated on a printed circuit board, comprising:
a microstrip input end, one end of the microstrip input end connecting an input end of the filter;
a first microstrip line, one end of the first microstrip line perpendicularly connecting the other end of the microstrip input end;
a microstrip output end, one end of the microstrip output end connecting to an output end of the filter;
an additional microstrip line, one end of the additional microstrip line perpendicularly connecting the other end of the microstrip output end, the additional microstrip line and the first microstrip line being interwovenly disposed in a interdigital finger form; and
a meandering microstrip line, two ends of the meandering microstrip line respectively connecting the other ends of the input end and the output end, and extending from said one end of the first microstrip line and said one end of the additional microstrip line;
wherein the meandering microstrip line further comprises a second microstrip line, the second microstrip line being extended from both the microstrip input end and the microstrip output end.
2. The filter of claim 1 , wherein the meandering microstrip line further comprises a third microstrip line, the third microstrip line being formed in a meandering shape, which connects to two ends of a second micro strip line corresponding to the first microstrip line and the fourth microstrip line, respectively.