A resonator device (100, 200, 300, 400, 500) for magnetic resonance comprising: a dielectric substrate; a ground plane on a first side of the substrate; conductors on a second, opposite side of the substrate, the conductors residing on the second, opposite side of the substrate, comprising: a first resonator on the second, opposite side of the substrate, wherein the first resonator is a first single elongate conductor strip; a second resonator on the second, opposite side of the substrate, wherein the second resonator is a second single elongate conductor strip, wherein the first and second elongate conductor strips are mutually parallel; and two baluns (102A, 102B) on the second, opposite side of the substrate, each respective balun comprising a feed (111A, 111B), a first branch and a second branch, the feed of each balun connected to the first and second branches of the balun, the first and second branches of each balun capacitively coupled to the respective first and second resonators in such a manner that each of the first and second elongate conductor strips extends between the baluns; and a sample region configured to support a magnetic resonance sample between the first and second resonators, wherein the first branch of each balun comprises a delay line (113A, 113B, 113C, 113D) configured to produce a phase shift relative to the second branch of the balun. a dielectric substrate; a ground plane on a first side of the substrate; conductors on a second, opposite side of the substrate, the conductors residing on the second, opposite side of the substrate, comprising: a first resonator on the second, opposite side of the substrate, wherein the first resonator is a first single elongate conductor strip; a second resonator on the second, opposite side of the substrate, wherein the second resonator is a second single elongate conductor strip, wherein the first and second elongate conductor strips are mutually parallel; and two baluns (102A, 102B) on the second, opposite side of the substrate, each respective balun comprising a feed (111A, 111B), a first branch and a second branch, the feed of each balun connected to the first and second branches of the balun, the first and second branches of each balun capacitively coupled to the respective first and second resonators in such a manner that each of the first and second elongate conductor strips extends between the baluns; and a first resonator on the second, opposite side of the substrate, wherein the first resonator is a first single elongate conductor strip; a second resonator on the second, opposite side of the substrate, wherein the second resonator is a second single elongate conductor strip, wherein the first and second elongate conductor strips are mutually parallel; and two baluns (102A, 102B) on the second, opposite side of the substrate, each respective balun comprising a feed (111A, 111B), a first branch and a second branch, the feed of each balun connected to the first and second branches of the balun, the first and second branches of each balun capacitively coupled to the respective first and second resonators in such a manner that each of the first and second elongate conductor strips extends between the baluns; and a sample region configured to support a magnetic resonance sample between the first and second resonators, wherein the first branch of each balun comprises a delay line (113A, 113B, 113C, 113D) configured to produce a phase shift relative to the second branch of the balun.