Transmission line and electronic device

An electronic device comprising:

• a first circuit substrate including a first circuit substrate first main surface and a first circuit substrate second main surface;
• and
• a transmission line electrically connected to the first circuit substrate to transmit a high-frequency signal;
• wherein
• the transmission line includes:
• a laminated body including a structure in which a plurality of insulator layers is laminated in a laminated body up-down direction, the laminated body including a first section, a second section, and a third section, the first section, the second section, and the third section being arranged in this order in a transmission direction of the high-frequency signal;
• a first signal conductor layer in the first section;
• a second signal conductor layer in the first section, the second section, and the third section;
• a third signal conductor layer in the third section;
• a first interlayer connection conductor that penetrates the insulator layer in the laminated body up-down direction in the first section and electrically connects the first signal conductor layer and the second signal conductor layer to each other;
• and
• a second interlayer connection conductor that penetrates the insulator layer in the laminated body up-down direction in the third section and electrically connects the second signal conductor layer and the third signal conductor layer to each other;
• the second signal conductor layer defines a coplanar line structure in the second section;
• a thickness of the second section in the laminated body up-down direction is smaller than a thickness of the first section in the laminated body up-down direction and a thickness of the third section in the laminated body up-down direction;
• a center of the second section in the laminated body up-down direction is above, in the laminated body up-down direction, a center of the first section in the laminated body up-down direction and a center of the third section in the laminated body up-down direction;
• a distance between the second signal conductor layer and a neutral plane of the second section in the laminated body up-down direction is shorter than a distance between the first signal conductor layer and the neutral plane of the second section in the laminated body up-down direction and a distance between the third signal conductor layer and the neutral plane of the second section in the laminated body up-down direction;
• a position of the second signal conductor layer in the laminated body up-down direction is above, in the laminated body up-down direction, a position of the first signal conductor layer in the laminated body up-down direction and a position of the third signal conductor layer in the laminated body up-down direction;
• a length of the second signal conductor layer between the first interlayer connection conductor and the second interlayer connection conductor is equal to or less than about ½ of a wavelength of the high-frequency signal;
• the plurality of insulator layers include a first layer that is an outermost layer in the laminated body up-down direction;
• the first layer is included in each of the first section, the second section, and the third section;
• and
• a portion of the first layer included in the second section is above, in the laminated body up-down direction, a portion of the first layer in the first section and a portion of the first layer in the third section.

A transmission line to transmit a high-frequency signal, the transmission line comprising:

• a laminated body including a structure in which a plurality of insulator layers is laminated in a laminated body up-down direction, the laminated body including a first section, a second section, and a third section, the first section, the second section, and the third section being arranged in this order in a transmission direction of the high-frequency signal;
• a first signal conductor layer in the first section;
• a second signal conductor layer in the first section, the second section, and the third section;
• a third signal conductor layer in the third section;
• a first interlayer connection conductor that penetrates the insulator layer in the laminated body up-down direction in the first section and electrically connects the first signal conductor layer and the second signal conductor layer to each other;
• and
• a second interlayer connection conductor that penetrates the insulator layer in the laminated body up-down direction in the third section and electrically connects the second signal conductor layer and the third signal conductor layer to each other;
• wherein
• the second signal conductor layer defines a coplanar line structure in the second section;
• a thickness of the second section in the laminated body up-down direction is smaller than a thickness of the first section in the laminated body up-down direction and a thickness of the third section in the laminated body up-down direction;
• a center of the second section in the laminated body up-down direction is above, in the laminated body up-down direction, a center of the first section in a laminated body up-down direction and a center of the third section in the laminated body up-down direction;
• a distance between the second signal conductor layer and a neutral plane of the second section in the laminated body up-down direction is shorter than a distance between the first signal conductor layer and the neutral plane of the second section in the laminated body up-down direction and a distance between the third signal conductor layer and the neutral plane of the second section in the laminated body up-down direction;
• a position of the second signal conductor layer in the laminated body up-down direction is above, in the laminated body up-down direction, a position of the first signal conductor layer in the laminated body up-down direction and a position of the third signal conductor layer in the laminated body up-down direction;
• the second section is bent such that an upper main surface of the third section and an upper main surface of the first section face each other;
• the plurality of insulator layers include a first layer that is an outermost layer in the laminated body up-down direction;
• the first layer is included in each of the first section, the second section, and the third section;
• and
• a portion of the first layer included in the second section is above, in the laminated body up-down direction, a portion of the first layer in the first section and a portion of the first layer in the third section.