Transmission line transformer and amplifying circuit

An amplifying circuit comprising:

• at least one amplifying system,
• each of the at least one amplifying system comprising:
• a substrate,
• an amplifying element that amplifies a high-frequency signal, and
• a transmission line transformer connected to an input terminal of the amplifying element or an output terminal of the amplifying element, the transmission line transformer comprising:
• a first transmission line, and
• a third transmission line disposed at a different position in the thickness direction of the substrate than the first transmission line, the third transmission line including a first end portion connected to one end portion of the first transmission line, the one end portion being connected to the amplifying element, and a second end portion that is AC-grounded, wherein:
• the first transmission line is electromagnetically coupled to the third transmission line,
• the first transmission line has a coil pattern, the third transmission line has a partially open loop pattern,
• the first transmission line coil pattern and the third transmission line partially open loop pattern each have an origin point, an end point, a path extending from the origin point to the end point, a first point on the path between the origin point and the end point, and a second point on the path between the origin point and the end point,
• the first transmission line coil pattern and the third transmission line partially open loop pattern each have a Euclidean distance from the origin point to the first point that is a maximum value and a Euclidean distance from the origin point to the second point that is a minimum value, and
• starting from a point at which the first transmission line is connected to the third transmission line, the first transmission line extends to turn in a first turn direction, and the third transmission line extends to turn in a second turn direction that is opposite to the first turn direction.