Cheese antenna

The antenna consists of a cylindrical parabolic reflector consisting of sheet metal with a parabolic curve in one dimension and flat in the other, with metal plates covering the open sides, and a feed antenna, almost always some sort of feed horn, in front, pointing back toward the reflector.

These are used when the location in a single plane is desired, which is often the case for horizon-scanning radars seen on ships.

The first example of the cheese was developed for the Royal Navy's Type 271 radar, allowing it to accurately measure the bearing to a target while having a wide vertical coverage so the reflection would remain in the beam while the ship pitched up and down in the waves.

Similar designs may also be found in height finding radars, with the antenna turned "sideways" in order to accurately measure the elevation angle.

These are not widespread, as most height finders used a modified "orange peel" design to focus in azimuth as well, in order to be able to pick out a single aircraft.

The Royal Navy Type 271 radar was the first application of the cheese design. This Type 274 used a "double cheese", with the upper surface made of wire mesh rather than a solid plate.