Closely spaced array of cavity backed slot antennas with pin curtains walls

An array of two cavity backed slot antennas with pin curtain walls is described. The use of pin curtains is shown to result in greatly reduced fabrication errors and improved repeatability. The effects of the pin curtain parameters on coupling between the array elements are investigated in order to establish design guidelines for achieving a mutual coupling performance which is as good as when using solid copper walls. It is found that these are not as strict as the general guidelines for pin curtains found in the literature. By means of extensive Finite Difference Time Domain simulations and measurements, the antenna performance characterised by impedance matching, radiation patterns and efficiency is shown to be unaffected when these pin curtains are used in place of solid copper walls. From this, a practical design has been arrived at.