DDS Function Generator Switching

Hello,

I would like to investigate QCM with dissipation monitoring by quartz crystal. Basic approach is opening and closing the function generator at crystal’s resonance level. I have 10MHz crystal. By AD9851(or any dds suggestion I would accept) I am going to give 10MHz sinusoidal signal. There is no issue with that but I want to see decaying signal. To do that, At least 5ms operate time switch(maybe relay) I need it. I dont want any distortion to signal to distort. What can I use as a switch for DDS? Thank you.