Optimization of a Subarray Structure to Improve the $G/T$ of an Active Array Antenna

In this letter, a subarray optimization to improve G/T of an active array antenna is presented. To optimize G/T, an equation for G/T is derived by calculating the formulas of the gain and noise temperature in the active array antenna. By using G/T and the peak sidelobe level of a scanned beam, the cost function is defined. Applying this cost function to the subarray optimization, a G/T value of 5.68 dB/K is obtained. To demonstrate the improved G/T, the subarray optimization without considering G/T is also conducted. Because G/T is not considered, some cases having low G/T is occurred. Compared to the worst case from these results, the proposed subarray optimization strategy improves G/T by 1.01 dB/K.