Odd shaped satellite dish - Page 1
Forum section: electronics / rf-microwave

author: Halcyon
author_rank: Unknown
timestamp: October 17, 2024, 06:17:03 am
content: Hi guys,I've travelled past this building numerous times, it's one of the NEP television studios in Sydney (https://www.nepgroup.com.au/find-studios/media-city-sydney-studio-1)On the roof, there is quite a large dish which always seems to be pointing in the same direction (at least every time I've driven past). What has me curious is the elongated feed horn, which doesn't seem to be focussed on just a single point.What's the purpose of this and how does it work? I dare say it's used for both transmission and reception. I haven't got a clear photo of it, but attached is the Google satellite view. You can just make it out at maximum zoom.

author: antenna
author_rank: Frequent Contributor
timestamp: October 17, 2024, 06:39:19 am
content: Is it possible that the "horn" is a series of slot antennas and the one they drive controls the direction of the pattern as a means to track satellites? Starlink uses a phased array of slot antennas from a flat surface to achieve directionality. Perhaps this is similar, but instead of phasing slots, it simply chooses one, then moves to the next and the shape of the reflector does the rest.

author: 2N3055
author_rank: Super Contributor
timestamp: October 17, 2024, 07:51:32 am
content: Array Fed Reflector Antenna ?

author: ftg
author_rank: Frequent Contributor
timestamp: October 17, 2024, 08:17:51 am
content: Looks like a multibeam antenna for monitoring multiple satellites at the same time.It could be an ATCi Simulsat:https://atci.com/products/simulsats-product-selector.htmlHere's some close up video of one:I think most of these setups are receive only.It would also make it much less flexible if one had to co-ordinate frequency use across tens of satellites and potentially fit the required filters.NEP being a TV studio makes receive-only also more possible.The dish next to it could be C-band or their uplink setup.Quote from: ATCihttps://atci.com/documents/atci/simulsat-faq.pdf

author: Halcyon
author_rank: Unknown
timestamp: October 17, 2024, 11:19:47 pm
content: Thanks ftg. The dish looks identical to the one you linked.

author: CaptDon
author_rank: Super Contributor
timestamp: October 18, 2024, 01:24:27 pm
content: Indeed receive only of multiple satellites across the same arc that a steerable dish would traverse. This dish can receive several different birds at the same time without needing to be steered. By the size and spacing it would not maintain a tight enough pattern to be legal for uplinking. The birds are closer together these days and that requires the 'tighter' patterns for uplinking. We had to replace some of our uplink dishes to avoid spillover interference to adjacent birds when they tightened the spacing up there. We were looking at some birds so low on the western horizon that the trash truck coming through the parking lot would kill the signal. And the twice a year sun outages were always fun. They would last 5 to 10 minutes and occur 2 or 3 days in a row. We would pick the same programming from a different bird which would also be effected, but at a different time.