Transmission line and mounting structure thereof

A transmission line comprising:

• a connecting portion connected to an outside;
• and
• a main body connected to the connecting portion;
• wherein
• the connecting portion includes a terminal electrode connected to an external electrode, a signal conductor, and a ground conductor;
• the main body includes a signal conductor and a ground conductor;
• the connecting portion includes a first region including the terminal electrode, a second region adjacent to the first region along a signal transmission path, and a third region between the second region and the main body;
• the first region has a capacitance component generated between the terminal electrode and the ground conductor larger than a capacitance component generated in the main body;
• the second region has an inductance component generated in the signal conductor larger than an inductance component generated in the main body;
• the third region has a capacitance component generated between the signal conductor and the ground conductor larger than the capacitance component generated in the main body;
• the signal conductor and the ground conductor in the third region include a gap closer than a gap between the signal conductor and the ground conductor in the main body;
• and
• the ground conductor in the third region includes a first ground conductor and a second ground conductor, and the second ground conductor is located between the signal conductor and the first ground conductor.