I see no issues working with piezoresistors at high
frequencies, e.g. there is nothing inherent in a
diffused silicon piezoresistor that would inhibit
performance at frequencies that ULSI CMOS devices
operate.

You will of course need to monitor your RC constants
and parasitics and design a mask layout and circuit
with good noise immunity.

--- T Zhu  wrote:

> Dear all:
>
> I am doing research on piezoresistive sensing
> issues, specipiclly, for
> the mechanical mixer applications, but in my
> knowledge, up to date, the
> piezoresistive approach is DC and for low frequency.
> But i am target at
> 20MHz, is that possible for piezoresistive sensing
> approach?
>
> Anyone got some advice on that,or suggest some
> literature for me?
>
> Thanks very much indeed.
>
> TT

--

Raj Gupta, Ph.D.
Volant Technologies
San Francisco, CA
http://terahz.org