The flat slot array antenna has a seven-layer structure, and the material is a certain anti-rust aluminum. It is composed of a slit array, a waveguide array, a partition, a feeder network, etc., and the diameter is less than 200mm. The parts are precisely processed by high-speed CNC milling. Both sides of the parts are processed with complex grooves. The thickness of the structure ranges from 0.5 to 2.0mm. The typical accuracy of the parts is 0.01mm. Needle-welded connections between layers are required. All contact surfaces are needle-welded. The brazing rate of the brazing seam of the working waveguide is basically 100%, without visible deformation, the flatness of the radiating surface is 0.1mm, and the brazing fillet is less than R0.2mm.
Due to the high requirements on the dimensional accuracy and welding rate of the flat seam array antenna, there are more than 100 brazing seams that need to be brazed, and the aluminum alloy brazing process is poor and easy to deform, which makes brazing difficult. The key of the brazing process is how to ensure a good welding rate and control the deformation to a minimum. The salt bath brazing process is commonly used in seam array antennas abroad. The process is complicated and pollutes and consumes energy. However, this antenna is brazed by the vacuum brazing process.
In order to ensure the necessary welding rate and dimensional accuracy, the design of the brazing tooling is very important. This brazing adopts an elastic tool with a sophisticated structure to ensure that the assembly gap occupied by the solder is effectively closed after the solder is melted. The compression mechanism can follow to compensate for the amount of collapse of the structure after the solder is melted, and maintain a certain degree of compression force. This can also effectively correct the original unevenness of the antenna parts, and control the size of the pressure to avoid excessive pressure. Large and deformed, which not only guarantees the quality of brazing, but also guarantees the dimensional accuracy.