Device using a filter with resonators
US8907747B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 5, 2012 |
| Grant date | Dec 9, 2014 |
| Priority date | — |
| Expiry date | Feb 9, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03H9/46
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A filter device including an input electronic circuit having an input load admittance Yin, an output electronic circuit having an output load admittance Yout, a lattice filter with two types of two piezoelectric resonators having a characteristic impedance Zc; those of the first type have a resonant frequency Fr1 and an antiresonant frequency Fa1; those of the second type have a resonant frequency Fr2 different from Fr1 and an antiresonant frequency Fa2 different from Fa1. The input and output impedances are matched to the reciprocal of the real part Re{Yin} of the admittance Yin and the reciprocal of the real part Re{Yout} of the admittance Yout, which are at least two to five times greater than the characteristic impedance Zc of the resonators. The frequency differences Fa1−Fr1 and Fa2−Fr2 are at least two to three times greater than the absolute value of the difference Fr1−Fr2.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.