Welcome to part 2 of the satellite dish teardown. Today we will be looking at the feed horn of the satellite dish that has spent the last 10 years being an ornament on my house. This will include looking at the radome, the shape of the feed horn and the internal features to make it work well.
So, this weekend was a perfectly normal weekend at the home of Swamphen Enterprises. It was one of those weekends spent sorting out all those things in the house you never quite get round to doing. One of these was deal with the satellite dish that the previous owner had left attached to the wall, but with the cable cut. This satellite dish has been acting as a decoration for the last 10 or so years, and it was time for this to end. You will be familiar with this dish, as it starred as one of my #AntennaInTheWild tweets and in my reflector blog post about how a perforated dish can act as a solid piece of metal: https://swamphen.co.uk/new-blog/2019/6/10/when-a-grid-becomes-a-solid. Having removed it from its long-held position, it was only fair to do a teardown of it!
Feed horns have always held a fascination for me, just make a bit of shaped metal and you can control electromagnetic radiation. In my opinion, a great super power to have! However, when you put several feed horns together you can create something even more powerful and informative.
A feed horn is a type of horn antenna, which means it is formed by flaring the sides of metal waveguide into a horn like shape thus creating a controlled beam of radio waves. A monopulse system is one that sends out multiple overlapping beams at the same time. Typically, a monopulse antenna is an antenna array which is symmetrical about boresight.