Transcript Piezoelectric Ceramics and It`s Application in Communication

Multimedia English Teaching PP.
Title: Application of
Piezoelectric Ceramics
in Communication system
Dr. & Prof. Chun-Huy Wang
Electronical Engineering
, Nan-Jeon Institute of Technology
＜Electronic Ceramics ＞
Dielectric
Piezoelectric
Pyroelectric
Ferroelectric
Dielectric Property
Piezoelectricity
Pyroelectricity
Ferroelectricity
What can piezoelectric ceramics do?
Piezoelectricity
Mechanical and electrical energy
conversion phenomena, discovered by
France Scientist Pierre and Jacques
Curie brother in 1880.
Direct Piezoelectric Effect
Mechanical
Electrical
Converse Piezoelectric Effect
Piezoelectricity
Piezoelectric Ceramics
 (perovskite)結構，化學式為
cornal
center
face
center
Pervoskite structure, with the chemical
formula as ABO3 e.g. : BaTiO3
Piezoelectric Ceramics
cornal
center
face
center
Domain and domain boundaries of polycrystalline BaTiO3
-(Jaffe et al. 1971),
(left)domain structure of unpoled ferroelectric ceramics –
(right) graphical representation
Poling
Poling is the final process in the
fabrication. Initially, unpoled ceramics
have no piezoelectricity because the
piezoelectric tensors of the grains are
randomly oriented.
 During the poling process, ferroelectric
switching occurs and creates non zero
overall piezoelectric tensors.
(1) unpoled
(2) during poling (3) after poling
P~E Curve
Domain Wall Movement
P~E curve vs Voltage Applied
Communication Applications
Piezoelectric ceramics used as the
resonator and filter in
communication system with
frequency lower than 100MHz。
For frequency higher than 100MHz，
the Surface Acoustic Wave (SAW)
devices is used.
Communication Applications
The ceramic filter and resonator are
made of high stability piezoelectric
ceramics that functions as a
mechanical resonator.
 The frequency is primary adjusted
by the size and thickness of the
ceramic element. Typical application
includes TVs, VCRs, telephones,
remote controls and radios.
Communication Applications
Operating Principle and feature of each filter
Ceramics Resonator
Resonator is the basic frequency
control component, the piezoelectric
filter is composed by the piezoelectric
resonator .
Ceramics Resonator
Ceramic Filter
Monolithic Filter (used for low frequency)
Ceramic Filter
SAW Resonator and Filter
 SAW : Surface Acoustic Wave
In natural world, SAW can
create by earthquake.
In engineering, SAW can
create by piezoelectric effect.
SAW Resonator and Filter
SAW Resonator and Filter
Advantages of SAW
 High Sensitivity
 High Accuracy
 Passive
 Wireless
 Digitalized
 Mass Production
 Many Application Possibilities
SAW Resonator and Filter
Two Port Resonator
One Port Resonator
SAW Resonator and Filter
Applications of
SAW Filter 
GSM
Applications of
SAW Filter 
PCS & CDMA
SAW Resonator and Filter
Applications of SAW Resonator
Thank you
For Listening！