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I'm new in electronics and I want to create a FM receiver that performs a product of the received RF signal and a local signal (the local signal is also frequency modulated with a Voltage Controlled Oscillator). I was thinking that a voltage controlled tunning receiver circuit could work. If true, where can I find a circuit diagram or in what kind of device could I find something that does what I want?

More details as requested: I'm trying to do a Frequency modulated continuous wave radar. No after demodulation is needed, the product signal will be sampled to a computer. The difference with any normal FM receiver is that I want my local oscillator to be a VCO. The band would be around 800Mhz.

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  • \$\begingroup\$ Superheterodyne = performs a product of the received RF signal and a local signal. What band? What modulation index? What received minimum power? What power supply? Plenty of stuff to state before anyone might offer a circuit. \$\endgroup\$
    – Andy aka
    Feb 28, 2015 at 14:01
  • \$\begingroup\$ What are you trying to accomplish? You seem to be describing the process used in most FM receivers where the incoming signal is mixed (multiplied) with a local oscillator to get a signal at the IF frequency for eventual demodulation and audio amplification. Depending on the receiver, the local oscillator control can be a tuning capacitor, a voltage, or a digital synthesizer. \$\endgroup\$
    – Barry
    Feb 28, 2015 at 14:02
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    \$\begingroup\$ I'm trying to do a Frequency modulated continuous wave radar. No after demodulation is needed, the product signal will be sampled to a computer. The difference with any normal FM receiver is that I want my local oscillator to be a VCO. The band would be around 800Mhz. \$\endgroup\$ Feb 28, 2015 at 14:09
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    \$\begingroup\$ This sounds a bit ambitions as a project for someone new to electronics. You can find plenty of papers proposing one circuit or another for FMCW radar. I don't know much about the topic myself, but hopefully someone will suggest something easy to build, although easy is probably going to be relative to a certain skillset... \$\endgroup\$ Feb 28, 2015 at 15:07
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    \$\begingroup\$ Thanks for the response. I'm planning to use a NE612 mixer, is it possible to couple it to a vco? how? what kind of things should I care about? \$\endgroup\$ Feb 28, 2015 at 18:34

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