A Broad-Band Coaxial Ferrite Switch (Correspondence)

A broad-band strip-line reflective ferrite switch has been described by Johnson and Wiltse, who also referred to the possibility of a similar switch in coaxial line. This note describes a coaxial on-off switch which will operate over the band 2500-4100 Mc; two such units can be combined to make a two-way switch. An isolation of 40 db was achieved, with a very low loss for the transmitting path, which, in both these devices, was obtained by magnetizing the ferrite well beyond the value for isolation.