High coupling, low loss saw filter and associated method

A surface acoustic wave device comprising:

• a single crystal LiNbO3 piezoelectric substrate for providing a propagation of a leaky acoustic wave, the substrate having an electromechanical coupling factor exceeding 5%, and an orientation defined by Euler angles (0±3°,θ,0±3°), with angle θ=90−θ′, where θ′ is a YX rotation angle of the substrate that ranges from about −40° to about −20°;
• an electrode pattern formed from electrodes provided on a surface of the piezoelectric substrate, the electrode pattern forming at least one resonator and the electrodes primarily formed from copper, wherein a thickness of the copper electrode pattern ranges from 0.15p to 0.25p, and wherein “p” being a period of the electrodes within the electrode pattern;
• and
• a dielectric overcoat comprising a SiOx, the dielectric overcoat having a positive TCF, the dielectric overcoat disposed between and over the electrodes of the electrode pattern, wherein a density of the electrodes substantially exceeds a density of the dielectric overcoat, the dielectric overcoat having a thickness in the range of hox/p=0.30*(hCu−0.15)/(0.20p−0.15)+/−0.05, wherein “hox” is a thickness of the overcoat as measured above a top surface of the electrodes, and “hCu” is a thickness of the electrodes within the electrode pattern.