Abstract: An inductor or transformer for use in integrated circuit devices that includes a high-resistivity substrate. The inductor includes a plurality of conductive traces around the substrate forming a continuous conductive path from a first to a second port. The conductive path can be solenoid-shaped. Some of the conductive traces can be formed during back-end-of-line processing or backside plating of an integrated circuit die. The transformer includes a first inductor with input and output ports, and a first continuous conductive path therebetween; and a second inductor with input and output ports, and a second continuous conductive path therebetween. The second inductor is independent of and electromagnetically coupled to the first inductor. The first and second conductive paths can be solenoid-shaped. The first conductive path can be interleaved with the second conductive path.