摘要 |
A filter is provided with a planar transmission line and a combined via structure connected to (both) one ends of the planar transmission line. The planar transmission line and the combined via structure are disposed in a same multilayer board. The combined via structure comprises two working parts. The first working part comprises a segment of signal via and a plurality of segments of ground vias surrounding the signal via. The second working part comprises a segment of the same signal via, a plurality of segments of the same ground vias, smooth conductive plate and corrugated conductive plate. The smooth conductive plate and the corrugated conductive plate are connected to the signal via. The second working part comprises a segment of the same signal via, a plurality of segments of the same ground vias and corrugated conductive plate. The corrugated conductive plate is connected to the signal via. |