Surface Acoustic Wave (SAW) Resonators utilize mechanical vibration of piezoelectric material, while LC/RC utilizes electrical resonance. Oscillators using a SAW Resonator are stable against peripheral circuit or supply voltage fluctuation, providing freedom from adjustment. SAW Resonator employs surface acoustic wave, and is able to be applied to high frequency circuit where conventional crystal, ceramic resonators are not available, as a resonator oscillates stably with its fundamental mode over frequency range from 200 MHz to around 1 GHz.

Surface Acoustic Wave (SAW) Resonator DesignSurface Acoustic Wave (SAW) is a type of mechanical wave motion which travels along the surface of solid material. Surface acoustic wave technology takes advantage of the piezoelectric effect in its operation. The basic surface acoustic wave device consists of a piezoelectric substrate, an input interdigitated transducer (IDT) on one side of the surface of the substrate, and an output interdigitated transducer on the other side of the substrate. The space between the IDTs, across which the surface acoustic wave will propagate, is known as the delay-line. This region is called the delay line because the signal, which is a mechanical wave at this point, moves much slower than its electromagnetic form, thus causing an appreciable delay.

Advantages of Surface Acoustic Wave (SAW) Resonators

Because the resonant frequency of a SAW device is not dependent on the entire mass of the substrate unlike conventional quartz devices, they are particularly suited to high frequency applications right into the gigahertz region. Having a high frequency fundamental oscillation mode increases simplicity and reduces design cost compared to traditional quartz with associated frequency multiplication circuitry. SAW Resonators too have an advantage over traditional LC / RC electrical resonance solutions in that the method of vibration is mechanical, and as such are not affected by fluctuations in supply or peripheral circuit voltage.

Applications of Surface Acoustic Wave (SAW) Resonators

SAW Resonator can be applied to many types of high frequency devices including RF remote controls, CATV FSK demodulators and CATV 2nd local oscillators. SAW Resonator is ideal for applications such as automotive keyless entry, tire pressure monitoring, gate and door openers, personal and home security, automated meter readers, wireless point of sale terminals, identification tags, bar code readers, and computer peripherals.