Described herein are new transmission line structures for use as resonators and non-resonant transmission lines in quantum circuits. In one aspect of the disclosure, a proposed structure includes a conductive shield structure provided over or in the substrate, a dielectric layer provided over the conductive shield structure, a first and a second ground plane structures provided over the dielectric layer, and a signal line structure provided over the dielectric layer, between the first and second ground plane structures. The conductive shield structure is electrically floating and each of the first and second ground plane structures and the signal line are provided opposite a respective portion of the conductive shield structure. Transmission line structures as proposed herein could be used for providing microwave connectivity to, from, or/and between the qubits, or to control the qubits. Methods for fabricating such structures are disclosed as well.