Multiple Array Spacings for an Interferometer Direction Finder With High Direction-Finding Accuracy in a Wide Range of Frequencies

In this letter, a novel method for achieving high direction-finding (DF) accuracy that is below 0.1° root mean square error (RMSE) in phase interferometer systems is proposed. To do this, unambiguous array spacing with maximum phase-difference error is first obtained, and then the set of array spacing with both the longest baseline and the maximum phase-different error is selected. An example to achieve an accuracy below 0.1° RMSE in the frequency range of 6-18 GHz with a field of view of 120° is provided to validate the proposed method. Simulation results show that 0.026° RMSE DF accuracy is achieved.