Octave Bandwidth UHF/L Band Circulator

Nonreciprocal ferrite devices - in particular, low-loss circulators - are increasingly difficult to realize at the lower microwave and UHF frequencies. Previous low-loss S-band and L-band circulators used a high-density magnesium manganese ferrite with aluminum substitution (General Ceramics R-6). Measurements show that the loss of R-6 in broad-band circulators increases rapidly when the operating frequency is decreased below 1100 Mc. Therefore, a new material is required for UHF application.