Direction Finding System Using Five-Element Circular Antenna Array Interferometer

We conducted a comprehensive analysis of the five-element circular antenna array interferometer direction finding system, examining both equal and unequal baseline structures along with their phase ambiguity characteristics. To enhance direction finding accuracy, we developed a weighted processing method for multi-baseline measurement data and established corresponding algorithms for weight coefficient selection and signal processing. The implementation workflow involves key components such as phase difference estimation using correlation algorithms, coordinate transformation through trigonometric calculations, ambiguity resolution via Chinese remainder theorem, and receiving channel error correction employing calibration matrices. Computer simulation results indicate that both baseline structures achieve nearly identical direction finding precision, with maximum error remaining below 0.10 across all directions in the ultra-short wave frequency range. These findings validate the effectiveness of our proposed methodology in improving direction finding system performance.