I've been using a Radiotronix DP-1205 RF transceiver that operates in the 915MHz unlicensed ISM band. The power level, operating frequency, FM deviation, etc., are set using the SPI serial interface. So I decided to see if my MHZ100Q A/D PCB could see the signal. I bypassed the antialiasing filter and associated buffer, and then coupled the transceiver signal to the input.
It Works! The signal is low amplitude (less than 10% of full scale), and there are a lot of spurs 20dB down or so, but the carrier is clearly visible. The 902 to 928 MHz band is being undersampled at 100 MHZ so it shows up at 2 to 28 MHz in the digitized signal (in full compliance with Nyquist's rules).
The A/D is only spec'ed to 550 MHz, so I wouldn't trust the signal and distortion levels, but it's definitely a usable signal.
More details on the MHZ100Q project site at Source Forge.
Showing posts with label undersampling. Show all posts
Showing posts with label undersampling. Show all posts
Monday, August 10, 2009
Subscribe to:
Comments (Atom)