Giggle Giggle .... you really don't like '1's do you!!
1 1/2 gig to 15 gig I have some prototype crossed Vivaldis.
So vertical and horizontal with the same phase center.
Minicricuits has some cute little broadband 90 deg hybrids. Next step is to design one of those into
the crossed Vivaldi's artwork and get broadband Circular Polarization.. There is a $5 one that would give CP on 12, 9, and 6 cm.at the same time. Cheers Kent G8EMY/W5
On Sunday, July 3, 2022, 10:28:18 AM CDT, Gareth G4XAT via groups.io <g4xat@...> wrote:
Perfect, thanks Kent, that way I can perhaps do all three bands with you 5-15 unit. The data looks promising so worth a try. Gareth
The phase center of a Vivaldi varies little with frequency.
Optimize at the higher frequency and you will be very very very close on the lower frequency.
Kent WA5VJB
On Sunday, July 3, 2022, 06:21:45 AM CDT, Gareth G4XAT via groups.io <g4xat@...> wrote:
I have a very nice prime focus dish feed for 5.7GHz and a nice old ex-Meteosat 90cm prime focus dish to fit it on. I started wondering about trying to convert the 5.7 circular feed to dual band, i.e 3.4 & 5.7. But the WG size of the 5.7 feed cuts off at around 3.8GHz according to an online calculator. So NO then..... I have a G3PHO modified feed on a 65cm offset dish but its a heavy old offset dish....
Or maybe I could do 5.7 and 10GHz from a single WG but with dual probes mounted as required?
I also have the Vivaldi PCB antennas that cover the frequency and can devise a simple adjustment to allow of feed position optimisation based on the desired band.
Am I in pursuit of the impossible? (I suspect yes...)
I have a very nice prime focus dish feed for 5.7GHz and a nice old ex-Meteosat 90cm prime focus dish to fit it on. I started wondering about trying to convert the 5.7 circular feed to dual band, i.e 3.4 & 5.7. But the WG size of the 5.7 feed cuts off at around 3.8GHz according to an online calculator. So NO then..... I have a G3PHO modified feed on a 65cm offset dish but its a heavy old offset dish....
Or maybe I could do 5.7 and 10GHz from a single WG but with dual probes mounted as required?
I also have the Vivaldi PCB antennas that cover the frequency and can devise a simple adjustment to allow of feed position optimisation based on the desired band.
Am I in pursuit of the impossible? (I suspect yes...)
