Design of low loss waveguide circulators at large peak and mean power levels

To avoid nonlinear losses at large signal level in ferrite devices, it is necessary to magnetize the ferrite material below subsidiary resonance, magnetize it at subsidiary resonance and suppress the onset of spinwave instability by broadening the spinwave linewidth, or bias it between the subsidiary and main resonances. A description is given of a very low loss S-band differential phase shift circulator and two different S-band junction circulators biased with direct magnetic fields between the subsidiary and main resonances.