Patent ID: 8242872

Claim:
An integrated transformer comprising: a semiconductor substrate prepared with a dielectric layer having a plurality of intermediate coil levels between top and bottom coil levels, the coil levels are separated by dielectric material of the dielectric layer, the coil levels are disposed along a transverse direction; a first coil element having n turns in the dielectric layer, the first coil element includes top first conductive concentric ring structures disposed in the top coil level, wherein dielectric material of the dielectric layer fills spaces between the top concentric ring structures, the top concentric ring structures include a plurality of inner top ring structures between innermost and outermost top ring structures, bottom first conductive concentric ring structures disposed in the bottom coil level, wherein dielectric material of the dielectric layer fills spaces between the bottom concentric ring structures, the bottom concentric ring structures include a plurality of inner bottom ring structures between innermost and outermost bottom ring structures, the top first concentric ring structures in the top coil level are in registration with the bottom first concentric ring structures in the bottom coil level, the top innermost ring structure of the first coil element is electrically coupled to the bottom first innermost ring structure of the first coil element and the top innermost ring structure of the first coil element is electrically coupled to the bottom innermost ring structure of the first coil element by innermost and outermost transverse connectors, the top first concentric ring structures are electrically coupled by top lateral connectors and the bottom first concentric ring structures are electrically coupled by bottom lateral connectors, wherein lateral connectors are separated from adjacent lateral connectors by dielectric material of the dielectric layer, and wherein the first top and bottom concentric ring structures form a cage like structure with perforations filled with dielectric material of the dielectric layer; a second coil element having second concentric conductive ring structures disposed in the plurality of intermediate coil levels in registration with the inner top and inner bottom ring structures of the first coil element to form second concentric ring stack groups, the second concentric ring stack groups are enclosed within the cage like structure of the first coil element, the second concentric ring stack groups are configured to form n turns for the second coil element; and wherein the first and second coil elements are arranged to increase mutual inductance of the coil elements in a multilateral direction to increase effective turn ratio of the integrated transformer.