Temperature compensated surface acoustic wave device and methods of manufacturing the same

A surface acoustic wave (SAW) device comprising:

• a piezoelectric substrate having a surface to support an acoustic wave;
• a plurality of resonators on the surface of the piezoelectric substrate, the plurality of resonators including at least a first resonator and a second resonator, wherein the plurality of resonators are formed by a plurality of electrodes, the first resonator has a first duty factor, the second resonator has a second duty factor, the first duty factor is larger than the second duty factor, and the first resonator is a series resonator where a width of individual electrodes of the plurality of electrodes forming the first resonator is larger than a width of individual electrodes of the plurality of electrodes forming the second resonator, wherein the width of the individual electrodes of the plurality of electrodes forming the first resonator and the width of individual electrodes of the plurality of electrodes forming the second resonator is such that the first duty factor is at least 10% greater than the second duty factor and the plurality of resonators includes a plurality of series resonators and a plurality of shunt resonators arranged in a ladder filter configuration, and the first resonator is one of the plurality of series resonators and the second resonator is one of the plurality of shunt resonators;
• and
• a dielectric layer having a positive thermal coefficient of frequency (TCF) and covering the plurality of resonators.

A wireless communication device comprising:

• a radio frequency front end (RFFE) circuitry comprising:
• a power amplifier module including one or more power amplifiers to amplify an outgoing radio frequency (RF) signal;
• and
• a surface acoustic-wave (SAW) device, coupled with the power amplifier module, comprising:
• a piezoelectric substrate having a surface to support an acoustic wave;
• a plurality of resonators including at least a first resonator having a plurality of electrodes on the surface of the piezoelectric substrate, and a second resonator having a plurality of electrodes on the surface of the piezoelectric substrate where a width of individual electrodes of the plurality of electrodes forming the first resonator is larger than a width of individual electrodes of the plurality of electrodes forming the second resonator and the plurality of resonators includes a plurality of series resonators, wherein the width of the individual electrodes of the plurality of electrodes forming the first resonator and the width of the individual electrodes of the plurality of electrodes forming the second resonator are such that a duty factor of the plurality of series resonators is at least 10% greater than a duty factor of a plurality of shunt resonators and the plurality of shunt resonators is arranged in a ladder filter configuration, and the first resonator is one of the plurality of series resonators and the second resonator is one of the plurality of shunt resonators;
• and
• a dielectric layer having a positive thermal coefficient of frequency (TCF) and formed on each of the plurality of electrodes, wherein an amount of the dielectric layer formed on the first resonator is different than an amount of the dielectric layer formed on the second resonator such that the first resonator or the second resonator is to obtain a TCF between +/−10 ppm/deg. C.;
• and
• a transceiver, coupled with the RFFE circuitry, to receive an incoming RF signal through the RFFE circuitry and provide the outgoing RF signal to the RFFE for transmission.