US 11,165,412 B2 · Zero-output coupled resonator filter and related radio frequency filter circuit

Abstract

A zero-output coupled resonator filter (ZO-CRF) and related radio frequency (RF) filter circuit are provided. In examples discussed herein, the ZO-CRF can be configured to function as a shunt resonator(s) in an RF filter circuit (e.g., a ladder filter circuit). The ZO-CRF includes a first resonator and a second resonator that are coupled to each other via a coupling layer. The first resonator and the second resonator receive a first voltage and a second voltage, respectively. The first voltage and the second voltage can be configured in a number of ways to cause the ZO-CRF to resonate at different resonance frequencies. As such, it may be possible to modify resonance frequency of the ZO-CRF in an RF filter circuit based on signal connection. As a result, it may be possible to reduce total inductance of the RF filter circuit, thus helping to reduce footprint of the RF filter circuit.

Claims18

Dependent claims

A zero-output coupled resonator filter (ZO-CRF) comprising:

a first resonator comprising a first electrode, a second electrode, and a first piezoelectric plate disposed between the first electrode and the second electrode, the first resonator configured to receive a first voltage between the first electrode and the second electrode;
a second resonator comprising a third electrode, a fourth electrode, and a second piezoelectric plate disposed between the third electrode and the fourth electrode, the second resonator configured to receive a second voltage between the fourth electrode and the third electrode;
a coupling layer disposed between the second electrode and the third electrode;
and
a tuning element configured to adjust the first voltage and the second voltage based on an input voltage to cause the ZO-CRF to resonate at a selected resonance frequency.

2 more elements

A radio frequency (RF) filter circuit comprising:

an input port configured to receive an RF signal;
an output port configured to output the RF signal;
a series resonator coupled between the input port and the output port and configured to resonate at a defined resonance frequency to pass the RF signal from the input port to the output port;
and
a zero-output coupled resonator filter (ZO-CRF) coupled between the series resonator and a ground, the ZO-CRF comprises:
a first resonator comprising a first electrode, a second electrode, and a first piezoelectric plate disposed between the first electrode and the second electrode, the first resonator configured to receive a first voltage between the first electrode and the second electrode;
a second resonator comprising a third electrode, a fourth electrode, and a second piezoelectric plate disposed between the third electrode and the fourth electrode, the second resonator configured to receive a second voltage between the fourth electrode and the third electrode;
a coupling layer disposed between the second electrode and the third electrode;
and
at least one tunable element configured to adjust the first voltage and the second voltage based on an input voltage to cause the ZO-CRF to resonate at a selected resonance frequency to shunt the RF signal to the ground.

7 more elements

Dependencies are inferred from the claim text.

Zero-output coupled resonator filter and related radio frequency filter circuit

Life of this patent

Zero-output coupled resonator filter and related radio frequency filter circuit

Life of this patent

Abstract

Claims18