A surface elastic wave resonator comprises a piezoelectric material to propagate the surface elastic waves and a transducer inserted between a pair of reflectors comprising combs of interdigitated electrodes and having a number Nc of electrodes connected to a hot spot and an acoustic aperture W wherein the relative permittivity of the piezoelectric material is greater than about 15, a product of Nc.Math.W/fa for the transducer being greater than 100 m.Math.MHz.sup.1, where fa is the antiresonance frequency of the resonator. A circuit comprises a load impedance and a resonator according to the invention and having an electrical response manifesting as a peak in the coefficient of reflection S.sub.11 at a frequency of a minimum value of the parameter S.sub.11 that is lower than 10 dB, the antiresonance peak of the resonator being matched to the impedance of the load.