Filtering ideas

pmlonline · 2006-03-14T16:56:48+00:00

Hello,I'm new at signal processing and was wondering if there's any newinnovative methods in detect very weak signals over noise. Signalexample less noise ->The signal lasts about 1/2 ms and a fraction of a uV. Noise couldpossible be hundreds times greater than signal. One advantage is thecircuit controls exactly when the signal fires. So at least thecircuitry knows exactly when to detect the signal. I would like tolimit the sampling time to 0.5 second.The input coil is 3.5" dia., 3.5" tall, 1000 turns of 24G, 23 ohms. Icalculate 60mH and guessing at about 8000 pF.Perhaps a common 1st stage would be a low noise op-amp followed by somefiltering-- perhaps an Elliptic filter is good at filtering out highend ->http://www.ortodoxism.ro/datasheets/lineartechnology/10696f.pdfPerhaps a PLL would make a good 3rd stage. I'm wondering if there areany other methods. Not sure if DSP could work since the STN is broadunless we're talking about a 24 bit ADC-- sounds like a lot of bits tome.Thanks,Paul