Masoud_A
Newbie level 1
Hello Dear Electronics Friends,
I have a question about Lock-In detection:
I have a signal that contains harmonics of 10 kHz sine wave. This signal is the output of a photodetector and is firstly generated by a DDS chip and patched to optical beam. I want to put together an analog Lock-In amplifier to extract harmonics of this 10 kHz signal. What I am planning to do is generating harmonics of 10 kHz with similar DDS chips that are being clocked synchronously; then, I will take each of these signals into AD8333 I/Q demodulators to generate complementary signals and at the end I will mix the photodetector signal with each of these complementary signals via AD630 balanced mod./demod. to get the Fourier Series coefficients (a1,b1, ...., an,bn). Finally I will detect these (an,bn) pairs with an FPGA module and calculate the amplitude and phase of each harmonics.
Since I am a mechanical student and not adroit at electronics, I don't know whether this is the right way or not. My goal is to shrink down the system as much as possible while getting synchronous detection of the harmonics.
I have a question about Lock-In detection:
I have a signal that contains harmonics of 10 kHz sine wave. This signal is the output of a photodetector and is firstly generated by a DDS chip and patched to optical beam. I want to put together an analog Lock-In amplifier to extract harmonics of this 10 kHz signal. What I am planning to do is generating harmonics of 10 kHz with similar DDS chips that are being clocked synchronously; then, I will take each of these signals into AD8333 I/Q demodulators to generate complementary signals and at the end I will mix the photodetector signal with each of these complementary signals via AD630 balanced mod./demod. to get the Fourier Series coefficients (a1,b1, ...., an,bn). Finally I will detect these (an,bn) pairs with an FPGA module and calculate the amplitude and phase of each harmonics.
Since I am a mechanical student and not adroit at electronics, I don't know whether this is the right way or not. My goal is to shrink down the system as much as possible while getting synchronous detection of the harmonics.
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