US 12,340,787 B2
Temperature compensated surface acoustic wave device and methods of manufacturing the same
Marc Solal, Longwood, FL (US)
Assigned to Qorvo US, Inc., Greensboro, NC (US)
Filed by Qorvo US, Inc., Greensboro, NC (US)
Filed on Sep. 26, 2023, as Appl. No. 18/372,850.
Application 16/369,007 is a division of application No. 14/730,001, filed on Jun. 3, 2015, granted, now 10,284,176, issued on May 7, 2019.
Application 18/372,850 is a continuation of application No. 16/369,007, filed on Mar. 29, 2019, granted, now 11,804,823.
Prior Publication US 2024/0014807 A1, Jan. 11, 2024
Int. Cl. H03H 9/64 (2006.01); B06B 1/06 (2006.01); G10K 9/125 (2006.01); G10K 11/18 (2006.01); G10K 11/36 (2006.01); H03H 3/02 (2006.01); H03H 3/08 (2006.01); H03H 9/02 (2006.01); H03H 9/145 (2006.01); H03H 9/25 (2006.01); H03H 9/54 (2006.01); H10N 30/06 (2023.01)
CPC G10K 11/18 (2013.01) [B06B 1/0622 (2013.01); G10K 9/125 (2013.01); G10K 11/36 (2013.01); H03H 3/02 (2013.01); H03H 3/08 (2013.01); H03H 9/02559 (2013.01); H03H 9/02834 (2013.01); H03H 9/14541 (2013.01); H03H 9/25 (2013.01); H03H 9/54 (2013.01); H03H 9/64 (2013.01); H03H 9/6483 (2013.01); H10N 30/06 (2023.02)] 9 Claims
OG exemplary drawing
 
6. A wireless communication device comprising:
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 that is coupled with the power amplifier module and that defines a passband having a lower side and an upper side, the 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
a dielectric layer having a positive thermal coefficient of frequency (TCF) and covering the plurality of resonators, wherein:
the dielectric layer has a first thickness that covers the plurality of electrodes forming the first resonator and the dielectric layer has a second thickness that covers the plurality of electrodes forming the second resonator;
a first electrode period is a first physical distance between each of the plurality of electrodes forming the first resonator and a second electrode period is a second physical distance between each of the plurality of electrodes forming the second resonator;
the first thickness is a first ratio times the first electrode period;
the second thickness is a second ratio times the second electrode period;
the first ratio is between 0.65 to 0.85 when the upper side has a steeper transition than the lower side and is less than or equal to 0.5 when the lower side has the steeper transition than the upper side; and
the second ratio is less than or equal to 0.50 when the upper side has the steeper transition than the lower side and is between 0.65 to 0.85 when the lower side has the steeper transition than the upper side; wherein one of the upper side and the lower side has a steeper transition than the other of the upper side and the lower side.