SAW-type transducers

Piezoceramic transducers are used to generate ultrasonic waves which propagate on the surface of the glass plate of a touch panel. When the panel is touched, a portion of the wave is absorbed. This change in the ultrasonic waves is used to determine the position of the touch event. This type of touch panel is known as SAW (surface acoustic wave) type touch panel. Unictron’s piezoceramic elements are developed to be used in SAW type touch panel of various sizes. Custom-made specifications or designs are available. Unictron’s piezoceramic elements are recognized for the high quality, durability and lower cost.
saw-type-touch-panel-transducer
A SAW type touch panel is made of a pure glass plate with no coating on it. Normally there are 4 piezoelectric ceramic transducers positioned at the corners of the glass plate (2 for transmitting and 2 for receiving ultrasonic signals). The piezoelectric ceramic transducers convert electric signals into ultrasonic waves which are sent to the array of reflectors on the glass surface and the acoustic waves are directed across the glass surface. The receiving piezoelectric transducers gather the directed waves from the reflectors and convert them into electrical signals. The coordinate of the touch point is calculated by comparing the received waveform profile to that of the stored in an untouched condition.

Unictron’s high-frequency thick film transducer elements can be designed to fit touch panels of different sizes. Custom-made specifications or custom-made designs are also available.

 

Applications

  • Piezoceramic transducers for the transmitting and receiving of acoustic signal in SAW (surface acoustic wave) type touch panels.

Characteristics

  • Fast touch response
  • High resolution
  • High light transmission
  • Durable, stable and accurate

 

Dimension (mm)
Resonant Frequency (MHz)
Impedance (Ω) at Resonant Frequency
Capacitance (pF) at 1 kHz
Operating temperature range (℃)
14 x 2 x 0.4
5.40 ± 0.15
<20
150 ± 20%
-10 ~ +60
17 x 2 x 0.4
5.40 ± 0.15
<20
190 ± 20%
-10 ~ +60
8 x 2 x 0.4
5.40 ± 0.15
<35
90 ± 20%
-10 ~ +60

* Other dimensions are available upon request.