Tunable compensation circuit for filter circuitry using acoustic resonators

Filter circuitry comprising:

• a first node and a second node;
• at least one series acoustic resonator coupled between the first node and the second node, wherein at least one main series resonance is provided between the first node and the second node at a main resonance frequency through the at least one series acoustic resonator;
• and
• a compensation circuit comprising:
• a first inductor and a second inductor coupled in series between the first node and the second node, wherein the first inductor and the second inductor are negatively coupled with one another and a common node is provided between the first inductor and the second inductor;
• a first shunt acoustic resonator coupled between the common node and a fixed voltage node;
• a second shunt acoustic resonator coupled between the common node and the fixed voltage node, wherein a first series resonance at a first resonance frequency and a second series resonance at a second resonance frequency, which is different from the first resonance frequency and main resonance frequency, are provided between the first node and the second node through the compensation circuit;
• and
• a first variable capacitor coupled between the common node and the fixed voltage node, wherein changing a capacitance of the first variable capacitor changes a bandwidth of a passband of the filter circuitry.