The Elements of Nonreciprocal Microwave Devices

This paper gives an elementary but nevertheless quite complete introduction to the basic theory of nonreciprocal microwave devices. The concept of reciprocity, itself, is introduced and some of the consequences which result when one violates reciprocity are pointed out. The basic theory of microwave ferrite devices is developed from a classical theory which gives one a strong intuitive feeling for extrapolating the theory to devices not discussed in the paper. The analysis is extended to include basic design criterion for the three general types of microwave ferrite devices which exist today. The operation of these devices are compared and advantages and disadvantages of the various devices are pointed out for the benefit of the component engineer.