I want to use an antenna for my project and want to use it in the frequency domain: 1GHz to 10 GHz. Is it possible to use a single antenna with dynamic input range? I read about reconfigurable antenna's but couldn't find anything concrete on it.
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\$\begingroup\$ Look up ultrawideband antennas, for PCB antennas I would look at spiral antennas. \$\endgroup\$– Captainj2001Commented Dec 19, 2016 at 16:07
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\$\begingroup\$ What radiation pattern is needed? \$\endgroup\$– Andy akaCommented Dec 19, 2016 at 16:40
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\$\begingroup\$ Perhaps a Log Periodic antenna? Or if you can live with a minimum frequency of more like 2.5-3GHz, perhaps this ultra wideband chip antenna \$\endgroup\$– SamCommented Dec 19, 2016 at 22:31
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\$\begingroup\$ I am looking for UWB antenna, I did find some Vivaldi antenna after picking up the keywords from your responses , Thanks. \$\endgroup\$– U7786Commented Dec 31, 2016 at 13:46
1 Answer
So, you can of course have something like a monopole antenna in a telescopic way, that you attach some motor to that changes the length – but to be honest, that'd be a bit awkward.
I'd recommend using something in between 2 and 5 separate antennas that all cover their share of the spectrum – for example, the first one could cover 1.0 – 1.6 GHz, the second 1.6 – 3.4 GHz, the next one 3.4 – 5.8 GHz, and the next one 5.8 – 10.6 GHz. That way, the relative bandwidth, ie $$\frac{f_{max}-f_{min}}{f_{center}}$$ would be roughly constant 0.5 for all antennas, and thus, you wouldn't need to build ultra-wideband antennas.
It's mathematically hard to build an antenna where this relative bandwidth gets large, but with self-complementary antennas like the Vivaldi antenna (if you need some directional gain) or self-complementary spiral antennas, one can achieve amazin bandwidths.
Note that saying "I need an antenna that covers 1 to 10 GHz" does sound a little unwise. It's extremely hard to build circuitry that works at 10 GHz the same way it works on 1 GHz, and antennas also typically serve a certain purpose. You don't even mention that – but it very much defines the types of antennas that are feasible for any given application. You might want to sit down and more exactly define your system's overall capabilities / requirements and then come back to ask more well-defined questions about your antenna.
In other words: the way you ask this question reflects a lack of understanding of RF principles, and thus, I doubt you have a system that would actually make use of 1 GHz to 10 GHz.
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\$\begingroup\$ Not all antennas are resonant. For example, a parabolic dish works well for any wavelength that is significantly shorter than its diameter. \$\endgroup\$ Commented Dec 19, 2016 at 16:09
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\$\begingroup\$ @DaveTweed that's absolutely true, but the bandwidth of the feed is typically limited; classical solutions to that problem are tapered waveguides, that, to little surprise, work similarly to things like a Vivaldi antenna in transforming free-space Z to waveguide Z \$\endgroup\$ Commented Dec 19, 2016 at 16:14