Which statement is true about crystal thickness and center frequency?

Which statement is true about crystal thickness and center frequency?

• A. Higher frequency requires thicker crystal
• B. Higher frequency requires thinner crystal
• C. Frequency is independent of thickness
• D. Lower frequency requires thinner crystal

Answer: (B)

In thickness-mode crystals, the center frequency is set by how thick the crystal is. For a given material and vibrational mode, the resonance condition is f = v/(2t), where v is the acoustic velocity and t is the thickness. This shows an inverse relationship: as thickness decreases, the frequency increases. So a higher center frequency requires a thinner crystal. The frequency isn’t independent of thickness, and a lower frequency comes from a thicker crystal, not a thinner one.

In thickness-mode crystals, the center frequency is set by how thick the crystal is. For a given material and vibrational mode, the resonance condition is f = v/(2t), where v is the acoustic velocity and t is the thickness. This shows an inverse relationship: as thickness decreases, the frequency increases. So a higher center frequency requires a thinner crystal. The frequency isn’t independent of thickness, and a lower frequency comes from a thicker crystal, not a thinner one.