Design and Fabrication of an Efficient Metallic Phased Array for TACAN Application

We propose a wideband, low-loss, low-cost, and high-gain metallic phased array for tactical air navigation (TACAN) systems. Such an array composed of 12 slot patch antennas with an air substrate. The element of this array has been optimized for working in 950 ~ 1250 MHz with a gain of 9 dBi. For using such an array in the TACAN system, an iterative method is utilized for synthesizing a cosecant-squared pattern (CSP). This method optimizes the element excitation in a linear phased array and allows having fewer ripples in the shaped region and lower sidelobe level (SLL). The obtained excitations by means of this method are realized using an all-metal feed network. Such a feed structure does not use any phase shifter and its dimensions are optimized on the air substrate to operate in the wideband frequency range and to be a low-loss and low-cost structure. To validate the numerical and analytical results, the entire system, i.e., the antenna array along with its feed network, is fabricated and successfully measured. The measurements on a 180 cm × 24 cm array and 550 mm × 350 mm feed network show a CSP with a maximum gain of 12.4 dBi and SLL <; -23 dB at the central frequency of TACAN bandwidth (962 ~ 1213 MHz).