Coplanar waveguide transmission line and design method thereof

A coplanar waveguide transmission line, comprising:

• a first dielectric substrate;
• a center conductor strip;
• two ground conductor strips;
• a metal ground layer;
• and
• a plurality of first metallized through holes;
• wherein the center conductor strip is configured to transmit a radio frequency signal, the two ground conductor strips are spaced on two opposite sides of the center conductor strip;
• the first dielectric substrate comprises a first surface and a second surface arranged opposite to each other, the center conductor strip and the ground conductor strips are stacked and fixed to the first surface;
• and
• the center conductor strip comprises:
• a first segment;
• and
• a second segment;
• the first segment is configured to connect to an external subminiature version A (SMA) connector, and the second segment extends from an end, distal from the SMA connector, of the first segment and configured to connect to an external chip;
• a distance perpendicular to an extension direction of the first segment toward the second segment is defined as width, and a width of the first segment is greater than a width of the second segment, to allow the first segment and the second segment to form a step structure, so as to realize impedance matching;
• a rectangular groove recessed toward the second surface is defined in the first surface;
• a part of the center conductor strip is stacked and fixed to a side, distal from the second surface, of the rectangular groove, to allow the rectangular groove to form a defected ground structure, so as to realize impedance matching of the radio frequency signal in a preset frequency band;
• the metal ground layer is stacked and fixed to the second surface, the plurality of the first metallized through holes pass through the first dielectric substrate, and the plurality of the first metallized through holes are respectively connected to the ground conductor strips and the metal ground layer;
• and
• the plurality of the first metallized through holes are arranged at intervals on two opposite sides of the center conductor strip.