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I have three questions with respect to an RF mixer. Let us consider this component - ADE-35MH+ from mini-circuits. The component has three pins - LO, RF, and IF.

  1. What is the output on IF? Is it LO + RF or LO - RF?
  2. Are the pins bidirectional mixer? means, IF and RF are both IN/OUT pins? Basically I want to know if it can act as up and downconverter
  3. How to find IF bandwidth for this mixer? My RF signal has 100 MHz bandwidth and after IF conversion, I need 100 MHz on the new frequency.
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    \$\begingroup\$ Datasheet links, please. (Put them in the question - don't hide them in the comments.) \$\endgroup\$
    – Transistor
    May 5, 2023 at 19:38
  • \$\begingroup\$ added the link for you, enemra. Next time, please do that yourself :) \$\endgroup\$ May 5, 2023 at 20:33
  • \$\begingroup\$ Thanks :) @MarcusMüller \$\endgroup\$
    – enemra
    May 8, 2023 at 21:51

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What is the output on IF? Is it LO + RF or LO - RF?

Both, usually. The same mechanism that upconverts also downconverts!

Are the pins bidirectional mixer? means, IF and RF are both IN/OUT pins?

Look at the performance graphs: The isolations specified wouldn't make sense if that wasn't the case.

Basically I want to know if it can act as up and downconverter

Whether RF or IF are higher in frequency is up to you to decide. This is a mixer, not specifically an up- or downconverter. Look up the mathematical theory of mixers – they simply produce sum- and difference-frequencies. With a frequency range so wide, it's not even possible that this device includes any filters to remove either!

How to find IF bandwidth for this mixer? My RF signal has 100 MHz bandwidth and after IF conversion, I need 100 MHz on the new frequency.

You have frequency behaviour graphs. Again, this is a mixer, not a specific downconverter or upconverter. Its bandwidth is its frequency range, where of course you need to watch out for higher-order intermodulations landing in your intended output – but that's not a bandwidth issue of your mixer, but of the signal and LO frequency you feed in.

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    \$\begingroup\$ And a mixer that multiplies in the time-domain is an up-and-down-converter, however many mixers (including this one) do not exactly multiply, but use some other nonlinear function that is cheaper, so you get all possible harmonic combinations of frequencies, like 2*RF - 3*LO and it's your job as a system designer to make sure these don't interfere with the one you want. (thankfully the more complicated combinations have lower amplitudes) \$\endgroup\$
    – user253751
    May 5, 2023 at 21:04
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    \$\begingroup\$ @user253751 exactly! That's why I mention the higher-order intermodulation products. \$\endgroup\$ May 5, 2023 at 21:08

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