Electroacoustic resonator, filter, duplexer and method for determining parameters of a resonator

A method comprising:

• obtaining a signal at a resonator;
• determining transmission characteristic curves of the resonator based on the obtained signal, the resonator having a resonator surface area for a fundamental mode and an nth-order spectral component generated in the resonator, where n is a whole number of at least two and the nth-order spectral component is selected from an nth-order harmonic and/or an nth-order intermodulation product, wherein, in the resonator, output signal power is determined as a function of input signal power;
• determining an intersection point of linearly extrapolated linear ranges of the transmission characteristic curves;
• determining an actual critical input signal power of the resonator based on the intersection point;
• comparing the actual critical input signal power to a predetermined target level for a critical input signal power;
• varying resonator surface area if there is a deviation of the actual critical input signal power from the predetermined target level;
• determining values of the actual critical input signal power for a series of resonator surface areas obtained by the varying;
• and
• determining a minimum value for the resonator surface area at which the actual critical input signal power of the resonator achieves the predetermined target level based on the values of the actual critical input signal power for the series of resonator surface areas.

A method comprising:

• obtaining a signal at a resonator;
• determining transmission characteristic curves of the resonator based on the obtained signal, the resonator having a resonator surface area for a fundamental mode and an nth-order spectral component generated in the resonator, where n is a whole number of at least two and the nth-order spectral component is selected from an nth-order harmonic and/or an nth-order intermodulation product, wherein output signal power of the resonator is determined as a function of input signal power of the resonator;
• determining an intersection point of linearly extrapolated linear ranges of the transmission characteristic curves;
• determining an actual critical output signal power of the resonator based on the intersection point;
• comparing the actual critical output signal power to a predetermined target level for a critical output signal power;
• varying the resonator surface area if there is a deviation of the actual critical output signal power from the predetermined target level;
• determining values of the actual critical output signal power for a series of resonator surface areas obtained by the varying;
• and
• determining a minimum value for the resonator surface area at which the actual critical input signal power of the resonator achieves the predetermined target level based on the values of the actual critical output signal power for the series of resonator surface areas.

A method performed using a resonator that is a bulk acoustic wave resonator, the method comprising:

• obtaining a signal at the resonator;
• determining transmission characteristic curves of the resonator based on the obtained signal, the resonator having a layer of thickness of a piezoelectric layer for a fundamental mode and an nth-order spectral component generated in the resonator, where n is a whole number of at least two and the nth-order spectral component is selected from an nth-order harmonic and/or an nth-order intermodulation product, wherein output signal power of the resonator is determined versus input signal power of the resonator;
• determining an intersection point of linearly extrapolated linear ranges of the transmission characteristic curves;
• determining an actual critical input signal power of the resonator corresponding to the intersection point;
• comparing the actual critical input signal power to a predetermined target level for a critical input signal power;
• varying the layer thickness of the piezoelectric layer if there is a deviation of the actual critical input signal power from the predetermined target level;
• determining values of the actual critical input signal power for a series of resonator thicknesses based on the varying;
• and
• determining a minimum value for the layer thickness at which the actual critical input signal power of the resonator achieves the predetermined target level based on values of the actual critical input signal power for a series of resonator thicknesses.