Beam scanning characteristics of microstrip triangular array antenna on normally biased NiAl ferrite

A conventional 4×4 planar microstrip equilateral triangular array antenna (METAA) is designed on a NiAl biased ferrite substrate in the C-band (5 GHz) region. The antenna shows tunability in resonant frequency, bandwidth, and efficiency and radiation conductance on application of an external magnetic field normal to the plane of the array geometry. The radar cross-section (RCS) characteristics, especially the resonance behavior of the array with various bias conditions, are studied and compared to the case of an unbiased ferrite. It is investigated that the RCS can be moved with respect to frequency by changing the magnetic bias field. It is also found that magnetic losses affect the RCS at resonance significantly.