I'm interested in evaluating the suitability of a standard-gain pyramidal horn for an ultrawideband (UWB) signal. However, I've had difficulty finding reliable information about the phase response over frequency that would be needed to make this determination.
In this context, use the FCC's definition of UWB, the relevant parts of which are:
- Operates in the 3.1 GHz to 10.6 GHz range
- Bandwidth greater than 500 MHz
The application I have in mind will not need to work over every frequency in that band, just a subset of it that is approx 500-2000 MHz wide.
Considerations w/ Wideband Antennas
There are many types of "wideband" antennas that can easily meet the bandwidth requirement (log periodic, horn, etc.). However, a good UWB antenna should also have these properties (according to ):
- Linear phase over the signal bandwidth
- Constant phase center over signal bandwidth
These conditions are necessary to prevent the UWB pulse from being distorted during transmission/reception. This is relevant to point out because many "wideband" antennas violate these conditions. E.g. a log-periodic antenna has a phase center that changes with frequency (i.e. as the frequency changes the active region changes), and some wideband antennas may have a relatively flat gain response over frequency, but might not have a linear phase over the entire band of interest.
Does a pyramidal horn antenna meet these requirements?
 Stutzman, Warren L., and Gary A. Thiele. Antenna theory and design. John Wiley & Sons, 2012.