High frequency quadrature signal generator

[kent]

Hi All

I would like to build a synchronous detection circuit for detecting the real and imaginary part of the signal (I and Q value), the operating frequency for the system is 20 MHz...I would like to know is there any existing chip that can generate the quadrature signal for me (cos wave and sine wave)? And I have never used a crystal as a signal source before...and anyone please give me some application tips about using crystal...Thanks

Kent

 

[berkeman]

To generate a quadrature signal, you can use a phase-locked loop (PLL):

http://en.wikipedia.org/wiki/Phase_locked_loop

And you would probably use Gilbert cell multipliers to do the detection, I would think:

http://www.odyseus.nildram.co.uk/RFIC_Circuits_Files/MOS_Gilbert_Cell_Mixer.pdf