An assembly includes a substrate, a chip mounted on the substrate, a voltage controlled oscillator circuit including an inductor and further circuit elements. The inductor is mounted on or in the substrate, and the further circuit elements are mounted on or in the chip. An assembly is disclosed that includes a substrate including a first metallization plane and a second metallization plane, a chip mounted on the substrate, and an inductor mounted on or in the substrate. The inductor includes a first inductor portion in the first metallization plane and a second inductor portion in the second metallization plane. An assembly is also disclosed including a substrate, a chip mounted onto the substrate, and a transformer formed at least in part on or in the substrate.