Multilayer piezoelectric substrate filters with consistent band balance
A die includes at least two surface acoustic wave resonators having different resonant frequencies. A first of the at least two surface acoustic wave resonators includes first interdigital transducer electrodes having a first duty factor and disposed on a multilayer piezoelectric substrate. The multilayer piezoelectric substrate a layer of piezoelectric material having a lower surface bonded to an upper surface of a layer of a second material different from the piezoelectric material. A second of the at least two surface acoustic wave resonators includes second interdigital transducer electrodes having a second duty factor different from the first duty factor and disposed on the multilayer piezoelectric substrate to improve band balance of a device formed from the at least two surface acoustic wave resonators.
1 . A die comprising:
at least two surface acoustic wave resonators having different resonant frequencies, a first of the at least two surface acoustic wave resonators including first interdigital transducer electrodes having a first duty factor and disposed on a multilayer piezoelectric substrate including a layer of piezoelectric material having a lower surface bonded to an upper surface of a layer of a second material different from the piezoelectric material, a second of the at least two surface acoustic wave resonators including second interdigital transducer electrodes having a second duty factor less than the first duty factor and disposed on the multilayer piezoelectric substrate to improve band balance of a device formed from the at least two surface acoustic wave resonators, the first of the at least two surface acoustic wave resonators having a higher resonant frequency than the second of the at least two surface acoustic wave resonators; and
a first radio frequency filter including the first of the at least two surface acoustic wave resonators and a second radio frequency filter including the second of the at least two surface acoustic wave resonators, the first radio frequency filter having a first passband and the second radio frequency filter having a second passband, the first passband having a higher center frequency than the second passband.
2 . The die of claim 1 wherein the first and second passbands are overlapping.
3 . The die of claim 1 wherein the first and second passbands are non-overlapping.
4 . The die of claim 1 further comprising a first duplexer including the first radio frequency filter and a second duplexer including the second radio frequency filter.
5 . The die of claim 4 wherein the first duplexer includes a first transmission filter and a first reception filter for a first radio frequency band, the first radio frequency filter being one of the first transmission filter or the first reception filter.
6 . The die of claim 5 wherein the second duplexer includes a second transmission filter and a second reception filter for a second radio frequency band, the second radio frequency filter being one of the second transmission filter or the second reception filter.
7 . The die of claim 6 wherein the first radio frequency band and second radio frequency band are overlapping.
8 . The die of claim 6 wherein the first radio frequency band and second radio frequency band are non-overlapping.
9 . The die of claim 1 wherein each of the first duty factor and the second duty factor is between 0.35 and 0.65.
10 . The die of claim 1 further comprising a silicon nitride trimming layer disposed on one of the first of the at least two surface acoustic wave resonators or the second of the at least two surface acoustic wave resonators.
11 . An electronics module having at least two radio frequency filters formed on a same die, a first of the at least two radio frequency filters including first resonators including a multilayer piezoelectric substrate and first interdigital electrode fingers having a first duty factor disposed on the multilayer piezoelectric substrate, a second of the at least two radio frequency filters including second resonators including second interdigital electrode fingers having a second duty factor greater than the first duty factor disposed on the multilayer piezoelectric substrate, the first radio frequency filter having a first passband and the second radio frequency filter having a second passband, the second passband having a higher center frequency than the second passband.
12 . The electronics module of claim 11 wherein the first resonators have lower resonant frequencies than the second resonators.
13 . The electronics module of claim 11 further comprising at least two duplexers, a first of the at least two duplexers including the first of the at least two radio frequency filters, a second of the at least two duplexers including the second of the at least two radio frequency filters.
14 . An electronic device including the electronics module of claim 13 .
15 . An electronic device with an electronics module having at least two radio frequency filters formed on a same die, a first of the at least two radio frequency filters including first resonators including a multilayer piezoelectric substrate and first interdigital electrode fingers having a first duty factor disposed on the multilayer piezoelectric substrate, a second of the at least two radio frequency filters including second resonators including second interdigital electrode fingers having a second duty factor greater than the first duty factor disposed on the multilayer piezoelectric substrate, the first radio frequency filter having a first passband and the second radio frequency filter having a second passband, the second passband having a higher center frequency than the second passband.
16 . The electronic device of claim 15 wherein the first resonators have lower resonant frequencies than the second resonators.