Hi all
According to my understanding, the basic purpose of quadrature Demodulation is to shift the band pass signal modulated at high frequency carrier to lower frequency region (near zero frequency) in order to reduce burden at ADCs as useful information is only present in pass band. Different types of ICs are used for this purpose e.g. AD8333 from "Analog Devices". FPGA based DDC cores are also there for this purpose.
Another technique used for demodulation is by "under sampling" i.e. Sampling at ADC is done well below the Nyquist criterai and use aliasing in own advantage by bringing higher frequencies in lower frequency region. My question is that is it not more simple to use this technique instead of using extra electronics (like AD8333) or FPGA resources?
Can anyone kindly explain what are advantages/disadvantages of both methods i.e. Demodulation using ICs/FPGA and by using "under sampling" principal?
According to my understanding, the basic purpose of quadrature Demodulation is to shift the band pass signal modulated at high frequency carrier to lower frequency region (near zero frequency) in order to reduce burden at ADCs as useful information is only present in pass band. Different types of ICs are used for this purpose e.g. AD8333 from "Analog Devices". FPGA based DDC cores are also there for this purpose.
Another technique used for demodulation is by "under sampling" i.e. Sampling at ADC is done well below the Nyquist criterai and use aliasing in own advantage by bringing higher frequencies in lower frequency region. My question is that is it not more simple to use this technique instead of using extra electronics (like AD8333) or FPGA resources?
Can anyone kindly explain what are advantages/disadvantages of both methods i.e. Demodulation using ICs/FPGA and by using "under sampling" principal?