Experimental Study of Fine Frequency Selection Techniques for Piezoelectric Aluminum Nitride Lamb Wave Resonators

Ting-Ta Yen

EECS Department
University of California, Berkeley
Technical Report No. UCB/EECS-2013-189
December 1, 2013

http://www.eecs.berkeley.edu/Pubs/TechRpts/2013/EECS-2013-189.pdf

Strong demand for high-Q resonators and filters in mobile wireless communication systems has initiated various research on radio frequency microelectromechanical systems (RF MEMS). Several CMOS-compatible RF MEMS resonator technologies, either electrostatic or piezoelectric, can provide multi-frequency operation on a single substrate and have the potential to realize a channel-select RF front-end architecture. However, utilizing a narrowband filter bank in such an architecture as the key component for frequency selection leads to a major challenge: fine frequency control. Depending upon the standard, it may entail the simultaneous fabrication of tens to hundreds of filters with 0.05 to 0.1% bandwidth, and spacing. Aluminum nitride (AlN) Lamb wave resonators (LWRs) utilize piezoelectric transduction to ensure low motional resistance. The resonance frequency of a LWR is defined by interdigital transducer (IDT) pitch and is thus decoupled from the overall device dimensions. This fine frequency selection technique is enabled by adjusting the so-called AlN "overhang" dimension allowing control of relative frequency of Lamb wave resonators in an array to 0.1%. Experimental results suggest the center frequency of LWRs can be linearly adjusted by up to 5% with no significant effect on other resonator parameters including Q, Rm, C0, and kt2. Closely and evenly spaced AlN Lamb wave resonators, without post-process trimming, demonstrate the potential to realize a pure mechanical, high performance, yet low power RF front-end system.

Advisor: Albert Pisano and Clark Nguyen


BibTeX citation:

@mastersthesis{Yen:EECS-2013-189,
    Author = {Yen, Ting-Ta},
    Title = {Experimental Study of Fine Frequency Selection Techniques  for Piezoelectric Aluminum Nitride Lamb Wave Resonators},
    School = {EECS Department, University of California, Berkeley},
    Year = {2013},
    Month = {Dec},
    URL = {http://www.eecs.berkeley.edu/Pubs/TechRpts/2013/EECS-2013-189.html},
    Number = {UCB/EECS-2013-189},
    Abstract = {    Strong demand for high-Q resonators and filters in mobile wireless communication systems has initiated various research on radio frequency microelectromechanical systems (RF MEMS). Several CMOS-compatible RF MEMS resonator technologies, either electrostatic or piezoelectric, can provide multi-frequency operation on a single substrate and have the potential to realize a channel-select RF front-end architecture. However, utilizing a narrowband filter bank in such an architecture as the key component for frequency selection leads to a major challenge: fine frequency control. Depending upon the standard, it may entail the simultaneous fabrication of tens to hundreds of filters with 0.05 to 0.1% bandwidth, and spacing.
    Aluminum nitride (AlN) Lamb wave resonators (LWRs) utilize piezoelectric transduction to ensure low motional resistance. The resonance frequency of a LWR is defined by interdigital transducer (IDT) pitch and is thus decoupled from the overall device dimensions. This fine frequency selection technique is enabled by adjusting the so-called AlN "overhang" dimension allowing control of relative frequency of Lamb wave resonators in an array to 0.1%. Experimental results suggest the center frequency of LWRs can be linearly adjusted by up to 5% with no significant effect on other resonator parameters including Q, Rm, C0, and kt2. Closely and evenly spaced AlN Lamb wave resonators, without post-process trimming, demonstrate the potential to realize a pure mechanical, high performance, yet low power RF front-end system.}
}

EndNote citation:

%0 Thesis
%A Yen, Ting-Ta
%T Experimental Study of Fine Frequency Selection Techniques  for Piezoelectric Aluminum Nitride Lamb Wave Resonators
%I EECS Department, University of California, Berkeley
%D 2013
%8 December 1
%@ UCB/EECS-2013-189
%U http://www.eecs.berkeley.edu/Pubs/TechRpts/2013/EECS-2013-189.html
%F Yen:EECS-2013-189