Timeline for Does an antenna pick up signals of all frequencies or only its resonant frequency?
Current License: CC BY-SA 4.0
19 events
| when toggle format | what | by | license | comment | |
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| May 31, 2023 at 8:46 | answer | added | Noji | timeline score: -1 | |
| Feb 17, 2022 at 20:48 | history | edited | Urthona26 | CC BY-SA 4.0 |
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| Feb 16, 2022 at 17:50 | comment | added | Mike Waters | You should move your comment to the question. | |
| Feb 16, 2022 at 17:42 | history | edited | Mike Waters | CC BY-SA 4.0 |
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| Feb 13, 2022 at 19:51 | comment | added | wbg | I suggest you reread the answers provided now that you begin to understand. There's impedance matching, radiation pattern, radiation resistance, RF grounding, transmission line loss, etc. So much for all of to learn and consider ! | |
| Feb 13, 2022 at 19:46 | comment | added | wbg | The following is highly simplified. Resonance is a feature or a bug depending on how you use it. For a mono band antenna you want resonance b/c it filters and has good gain. But if you cannot b/c of space limitations then you can load the antenna to look electrically longer but the wave length will not match the geometry. Then gain is not as great and there's loses but it works good enough. People built very complex antennas for their home station but for mobile I tend to stick really simple ones and take whatever loses I have to. | |
| Feb 12, 2022 at 23:01 | answer | added | AG5CI | timeline score: -1 | |
| Feb 11, 2022 at 17:28 | comment | added | Urthona26 | I think I understand. So an antenna can pick up a signal that's so weak that humans can't use it. So resonant frequency is important. But if that's the case, how can a very short antenna on my personal radio tune into longwave stations? Doesn't an antenna need to be hundreds of metres long to have this sort of resonant frequency? Is it because resonant frequency is more important for transmission than reception - so an antenna needs to be very tall to transmit low frequencies but even a short antenna can pick them up? | |
| Feb 10, 2022 at 20:45 | comment | added | wbg | Recall that a resonant antenna has a very narrow band pass. Also, many antenna are NOT resonant. Being resonant means you will get maximum power transfer as I understand it but it also acts like a filter. Also read about RLC filter circuits. | |
| Feb 10, 2022 at 20:44 | comment | added | wbg | It cannot receive ANY frequency only a set. Just because it receives doesn't mean there's enough gain to be useful. Antennas also transmit so even if there's enough gain to receive you will not be able to transmit. Also, the receiver tuner doesn't have infinite ability to tune. Read about heterodyne detection. The incoming frequency is shifted and there's some limiting factors there. | |
| Feb 10, 2022 at 19:23 | comment | added | Urthona26 | But if the antenna can receive signals of any frequency, and the tuning circuit filters out all the unwanted frequencies, why is it necessary to design antennas with a specific resonant frequency? Couldn't we use an antenna of any resonant frequency and just use the tuning circuit to get the frequency we want? That's what I want to know. | |
| Feb 10, 2022 at 9:00 | history | tweeted | twitter.com/StackHam/status/1491698459866501120 | ||
| Feb 9, 2022 at 1:02 | comment | added | wbg | It may help your understanding, if you know that the receive circuit on most radios are very good at amplifying small signals. Even a poor choice of antenna for a certain band could allow the receiver to pick something out and provide enough gain to hear. That doesn't mean such an antenna will be able to transmit useful power on that band. | |
| Feb 7, 2022 at 23:08 | answer | added | hotpaw2 | timeline score: 4 | |
| Feb 7, 2022 at 18:46 | answer | added | rclocher3 | timeline score: 2 | |
| Feb 7, 2022 at 15:11 | answer | added | Wireless Learning | timeline score: 0 | |
| Feb 7, 2022 at 12:35 | answer | added | user10489 | timeline score: 2 | |
| S Feb 7, 2022 at 6:57 | review | First questions | |||
| Feb 7, 2022 at 15:12 | |||||
| S Feb 7, 2022 at 6:57 | history | asked | Urthona26 | CC BY-SA 4.0 |