# Open circuit resonance

For a piezoelectric system, a mechanical resonance whose frequency /( f_{oc} /) corresponds to a condition where the piezoelectric ceramics are open circuited (not connected together). (See Hirose[1], p. 213.) The piezoelectric system may consist of piezoceramic(s) alone, piezoelectric transducer(s), or piezoelectric transducer(s) plus attached resonators.

Open circuit resonance is characterized by high impedance (i.e., low admittance) which yields relatively low amplitude for a given drive voltage.

An open circuit resonance is always accompanied by a somewhat lower short circuit resonance. See Comparison of short circuit resonance and open circuit resonance.

This resonance condition is often called "parallel resonance". However, the meaning behind this terminology requires an understanding of the piezoceramic's equivalent circuit whereas the concept of "open circuit resonance" is physically intuitive and is therefore preferred.

Historically this resonance condition has been called "antiresonance". However, since "antiresonance" is an actual resonance condition, "antiresonance" is an oxymoron which should be avoided.