High Quality Factor Integrated Acoustic Resonant Metamaterials with Giant Frequency Tuning Range (>30%) for Reconfigurable Radio-Frequency (RF) Front-Ends

INV-20003

Background

The need for miniaturized radios have increased the need for reconfigurable CMOS-compatible RF front-ends. Tunable bandpass/notch filters and wide tuning range low-jitter Voltage Controlled Oscillators (VCOs) are desirable to form adaptive, low-power and miniaturized multi band radios.

In the last decades, Aluminum Nitride (AlN) acoustic resonators have been used to form (1-5GHz) CMOS-compatible filters and VCOs. However, because of material limitations, these devices only enable a low tuning range (<2-3%) and moderate Q-values (~2000).

Technology Overview

In this invention, the proposed resonator is based on the adoption of a novel metamaterial structure that is formed by a periodic sub-wavelength arrangement of locally resonant magnetostrictive FeGaB thin rods placed on the top side of a thin AlN piezoelectric film. The AlN layer is sandwiched by two interdigitated metal electrodes (IDTs). Also, a set of coils crossed by a DC-current (IDC) is deposited on the top surface of the rods to produce the magnetic flux (B) that changes their Young’s modulus. Adjacent metal strips forming the top and bottom IDTs are connected to opposite voltage polarities so that a large electric field can be excited in the thickness of the AlN layer. Each periodic cell forming a pRAM is formed by two sets of different regions, which is labeled as “Regions-A” and “Regions-B”.

Benefits

- CMOS-compatible acoustic resonators capable of achieving tuning ranges in excess of 30%

- The displacement modal characteristics of pRAMs permit to confine the acoustic energy far from the metal electrodes

- The design criteria and theory applied to AlN pRAMs can be extended to any other piezoelectric material (PZT, Lithium Niobate, Aluminum Scandium Nitride)

- The design criteria and theory applied to AlN pRAMs can be extended to the design of high-sensitivity sensors, such as magnetometers, electric field sensors, physical and chemical sensors

Applications

- Matching networks in commercial and military RF front-ends

- Communication systems

- 4G/5G radio-modules

Opportunity

- License

- Partnering

- Research collaboration