Thin-Film, Lumped-Element Circulator.

The development of a miniature broadband UHF circulator was investigated. The basic design was evolved from Konishis work on lumped-element circulators. Thin-film techniques were used to implement the resulting circuit design. The methods of Knerr involving a common capacitance to achieve broadband performance were implemented. The effects of ferrite saturation magnetization, ferrite thickness, crossover capacitance, common capacitance, and applied magnetic field were studied. A circulator was produced in a 34 inch cube format with less than 1 dB insertion loss, 10 dB isolation over 200 MHz, centered at 860 MHz. Author