Resonance isolator and Y circulator with lumped elements at VHF

The paper describes a resonance isolator and a circulator, with lumped elements for the frequency range between 200 mc/s and 240 mc/s. The isolator provides an isolation of 20 dB, an insertion loss of 0.7 dB and VSWR <1.1 in the range of 220 to 240 mc/s. The circulator operates between 205 and 215 mc/s. The isolation is >20 dB, the insertion loss 0.5 dB and VSWR <1.2. The design of the coils generating the magnetic RF fields is described in detail. Contributions to the theory and information on the selection of the material and the applied circuit are given. Finally the characteristics of the two devices are compared.