A Broad-Band Microwave Circulator (Correspondence and Authors' Reply)

Edward A. Ohm has recently shown some applications of microwave circulators, first suggested by A. G. Fox, S.E. Miller, and W.W. Mumford of the Bell Telephone Laboratories. One in particular, a circulator microwave modulator, I believe, needs some further discussion. This device is shown in Fig. 1. As shown, the energy from the oscillator travels to the port containing the modulator, where it is modulated, reflected from the short circuit, passed back through the modulator and to the output arm of the circulator. Let us consider what occurs if the modulator is a typical ferrite type modulator, like those commercially available. This modulator is shown in Fig. 2.