A Unidirectional Transducer Design for Scaling GHz AlN-Based RF Microsystems

Area of Science:

• Materials Science
• Electrical Engineering
• Acoustics

Background:

• Aluminum nitride (AlN) is a key material for radio frequency (RF) microsystems.
• Existing AlN transducers face limitations in frequency scalability and insertion loss.
• Unidirectional transducers are crucial for efficient RF signal processing.

Purpose of the Study:

• To introduce a novel unidirectional transducer design for AlN-based RF microsystems.
• To enhance frequency scalability and reduce insertion loss in AlN transducers.
• To validate the performance of the proposed transducer design.

Main Methods:

• Design and theoretical exploration of thickness-field-excited single-phase unidirectional transducers (TFE-SPUDT) with 5/16 wavelength electrodes.
• Experimental validation using acoustic delay line (ADL) testbeds.
• Characterization of center frequency, insertion loss (IL), and fractional bandwidth (FBW).

Main Results:

• The TFE-SPUDT design enables efficient piezoelectric transduction with improved frequency scalability.
• ADL testbeds demonstrated a 1 GHz center frequency, 4.9 dB minimum IL, and 5.3% FBW.
• Performance significantly surpasses previously reported AlN transducers in terms of IL and frequency scalability.

Conclusions:

• The proposed TFE-SPUDT design offers superior performance for AlN-based RF microsystems.
• This advancement contributes to signal processing, sensing, and quantum acoustic applications.
• The design is readily extendable to other piezoelectric platforms.