Coupled slot waveguide s.a.w. resonators

Grooved-grating, waveguided s.a.w. resonators are coupled by the evanescent fields of single-mode slot waveguides formed by layers of MgO on SiO2 substrates. Except for higher out-of-band levels, the transfer characteristics of these devices compare favourably with alternative monolithically coupled s.a.w.-resonator geometries. A 4-pole response with a 3 dB bandwidth < 20 kHz and insertion loss < 6 dB is illustrated at 131.5 MHz.