A Novel Nested Array for Real-Valued Sources Exploiting Array Motion

Abstract

In this letter, a novel nested array is proposed which not only increases the degrees of freedom (DOF) but also reduces the mutual coupling that occurs in the general nested array structure by moving the original array only half wavelength. Here we deal with real-valued sources like AM or BPSK whereby we can explore the property of the sum coarray along with the difference coarray of the synthetic array (SA). It is assumed that the sensing environment does not change over the array motion of half wavelength. First, we develop the novel nested array and prove that the sum difference coarray (SDCA) of SA is hole-free up to a certain number. Then we provide closed-form expressions for the number of unique and consecutive lags of the SDCA of SA. We also optimize the array for a given number of sensors. Simulation results show the superiority of the proposed array over other existing arrays.