Temperature Compensation of VHF-band Lumped-Element Ferrite Circulator for Wireless Communication Application

Abstract

The design of a VHF-band lumped-element ferrite circulator has been introduced. The experiments have indicated that the ferrite circulator has good performances in the room temperature. However, when the ambient temperature has changed, the significant degradations of performances of the ferrite circulator have been observed. A temperature-compensation technique has been adopted to guarantee the good performances of the ferrite circulator, in which one kind of special alloy has been employed and an experimental prototype has been constructed. The measured data have shown that, excellent performances can be obtained in the frequency range 140–180 MHz and over 20 dB isolation has been guaranteed throughout the temperature range of 0°C∼ 70°C.