TC-SAW Design Study

Temperature compensation technology in Surface Acoustic Wave (TC-SAW) devices allows for improvement in their performance. OnScale enables designers to explore many TC-SAW device design spaces to offer a greater insight into the optimum design.

In this example, we simulate a 3D unit cell model of a TC-SAW device to analyse the effect of electrode and Si02 thickness on the electrical performance.

Model Setup

A schematic of the model and the two input variables can be seen below:

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Basic Model Schematic

Parametric Variables

The key model parameters were as follows:

Parameter

Description

Default Value

subs_thk

Thickness of substrate

10 µm

elec_thk

Thickness of the electrodes

100 nm

si02_thk

Thickness of Si02 layer

250 nm

fin_pitch

SAW finger pitch

1 µm

nfing

Number of finger pairs

80

ncycles

Simulation length in cycles

2000

freqint

Centre frequency

1.9 GHz

The design variable electrode thickness was swept from 100nm to 200nm in 14 steps and the Si02 thickness was swept from 250nm to 400nm in 14 steps. This resulted in a total of 196 simulations which were run in parallel.

Simulation Sweep Results

The full simulation sweep was completed in 2 minutes when using 8 cores per simulation and had a total cost of 52 core hours.

Using the outputs from the simulations, it is possible to calculate the device impedance, Q factor, resonance frequency and coupling coefficient. These outputs can all be plotted against the input variables to provide an insight into the device performance as shown in the image below:

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