High efficiency on-chip 3d transformer structure

An integrated circuit transformer structure, comprising:

• at least two conductor groups, each conductor group forming a spiral, the spirals of the at least two conductor groups being stacked in parallel in different layers;
• the spirals including:
• turns of a first radius connected in series between the layers to form a first cylinder of turns within the at least two conductor groups;
• turns of a second radius connected in series between the layers to form a second cylinder of turns within the at least two conductor groups;
• and
• turns of a third radius connected in series between the layers to form a third cylinder of turns within the at least two conductor groups, wherein the first and the third cylinder are electrically connected to each other and electrically isolated from the second cylinder.

A method for constructing an integrated circuit transformer structure, comprising:

• forming at least two conductor groups, each conductor group forming a spiral, the spirals of the at least two conductor groups being stacked in parallel in different layers;
• forming turns of a first radius for the spirals, which are connected in series between the layers to form a first cylinder of turns within the at least two conductor groups;
• forming turns of a second radius for the spirals, which are connected in series between the layers to form a second cylinder of turns within the at least two conductor groups;
• and
• forming turns of a third radius for the spirals, which are connected in series between the layers to form a third cylinder of turns within the at least two conductor groups, wherein the first and the third cylinder are electrically connected to each other and electrically isolated from the second cylinder.