Variable inductance circuit

An acoustic ladder network comprising:

• at least one acoustic resonator configured to:
• resonate at a series resonance frequency range to pass a signal from a signal input to a signal output;
• and
• block the signal between the signal input and the signal output in a parallel resonance frequency range outside the series resonance frequency range;
• and
• a variable inductance circuit comprising:
• a first terminal coupled to the signal input and a second terminal coupled to the signal output;
• an impedance inverter circuit comprising an input node coupled to the first terminal, an output node coupled to the second terminal, and an intermediate node coupled to a selected one of the first terminal and the second terminal;
• and
• a variable capacitance circuit coupled between the impedance inverter circuit and the selected one of the first terminal and the second terminal and further to the intermediate node, the variable inductance circuit is configured to present a variable capacitance between the impedance inverter circuit and the selected one of the first terminal and the second terminal to thereby cause a variable inductance between the first terminal and the second terminal to thereby offset an electrical capacitance associated with the at least one acoustic resonator within a target frequency range.

A wireless device comprising an acoustic ladder network, the acoustic ladder network comprises:

• at least one acoustic resonator configured to:
• resonate at a series resonance frequency range to pass a signal from a signal input to a signal output;
• and
• block the signal between the signal input and the signal output in a parallel resonance frequency range outside the series resonance frequency range;
• and
• a variable inductance circuit comprising:
• a first terminal coupled to the signal input and a second terminal coupled to the signal output;
• an impedance inverter circuit comprising an input node coupled to the first terminal, an output node coupled to the second terminal, and an intermediate node coupled to a selected one of the first terminal and the second terminal;
• and
• a variable capacitance circuit coupled between the impedance inverter circuit and the selected one of the first terminal and the second terminal and further to the intermediate node, the variable inductance circuit is configured to present a variable capacitance between the impedance inverter circuit and the selected one of the first terminal and the second terminal to thereby cause a variable inductance between the first terminal and the second terminal to thereby offset an electrical capacitance associated with the at least one acoustic resonator within a target frequency range.