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I'm supposed to do a class report on microware antennas. The report said we have to present 1 microwave antenna that sends digital signal and another that sends analog signals.

Do you know such specific antenna ? (I'll then work on googling their technical specifications)

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    \$\begingroup\$ Then either the report is incorrect in its assumptions about the nature of things or you are misrepresenting said report. \$\endgroup\$
    – Andy aka
    Jan 23, 2017 at 11:16
  • \$\begingroup\$ @Andyaka I'm starting to realize it with the answer below. Anyways this is what I heard in class (knowing my teacher I'm not even surprise about you guys reactions) \$\endgroup\$
    – Jason Krs
    Jan 23, 2017 at 11:18
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    \$\begingroup\$ It may be talking about bands that are dedicated to data transmissions versus (different) bands that are dedicated to linear (or analogue) transmissions. \$\endgroup\$
    – Andy aka
    Jan 23, 2017 at 11:41
  • \$\begingroup\$ @Andyaka Please see the update on my OP \$\endgroup\$
    – Jason Krs
    Jan 23, 2017 at 12:41
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    \$\begingroup\$ Sadly it's not unusual to have teachers that don't themselves really understand the material, and therefore ask nonsensical questions. \$\endgroup\$
    – pjc50
    Jan 23, 2017 at 13:22

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No. There's no physical difference between digital signals and analog signals on the air. Both are converted to analog voltages.

The only things about the electrical system that attaches to the antenna that matter for an antenna are

  • center frequency
  • bandwidth
  • impedance

Selling an antenna "for digital transmissions" is like selling a car to "transport green apples". The color of apples doesn't have anything to do with their transportability. The question whether the data that is modulated onto a microwave signal is analog or digital has nothing to do with their bandwidth, center frequency or the device's impedance.

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  • \$\begingroup\$ okay. But are there antennas (or their associated control boxes) that can only perform digital or analog ''tasks'' or both (though on the air it's all analog) ? \$\endgroup\$
    – Jason Krs
    Jan 23, 2017 at 11:08
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    \$\begingroup\$ Antenna directivity and gain also matter in most cases. \$\endgroup\$
    – neonzeon
    Jan 23, 2017 at 11:13
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    \$\begingroup\$ @JasonKrs that doesn't actually mean anything – it just meant to say "this works well for usage with digital systems". Simply because almost all microwave links are digital these days. It's marketing speech. You can buy "WiFi antennas" at every electronics store. They are not specifically for WiFi – they just work well at the frequencies that wifi runs at (and can be just as well used for any other system at the same frequencies); if you ask a question and get an answer… \$\endgroup\$
    – Marcus Müller
    Jan 23, 2017 at 11:35
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    \$\begingroup\$ what did I just explain? there is no such thing as a digital or analog antenna \$\endgroup\$
    – Marcus Müller
    Jan 23, 2017 at 11:40
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    \$\begingroup\$ selling an antenna "for digital transmissions" is like selling a car to "transport green apples". The color of apples doesn't have anything to do with their transportability. The question whether the data that is modulated onto a microwave signal is analog or digital has nothing to do with their bandwidth, center frequency or the device's impedance. \$\endgroup\$
    – Marcus Müller
    Jan 23, 2017 at 11:44
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Your "control boxes" are Modems (short for MODulator/DEModulator).

Of course, these boxes need to be aware of what kind of transmission they do. You can transmit any sufficiently band-limited signal over an RF link.

So these boxes might just be transmitting garage door opener codes, they might be transmitting analog audio that is analogly modulated as FM, they might transmit the same audio modulated as analog AM, but they might also transmit that same audio using a digital audio transmission standard.

Realistically, microwave communication links of the last 30 years can be expected to be digital, since you usually want to transmit data that is already in digital form, anyway.

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  • \$\begingroup\$ @JasonKrs I'm sorry, but please don't do such things. It's bad style. Ask a separate question that everyone sees. \$\endgroup\$
    – Marcus Müller
    Jan 23, 2017 at 18:16
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You can find an application from 1950's - maybe a radar or telephone multichannel link, definitely analog. Then a digital application of today, maybe a desktop WiFi-box or a car door remote controller opened to show the microstrip antenna.

You should notice and say that the radiowave is the same - so is the antenna, only signals have different modulations. That is well told in the comments and other answers.

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