Study of a low-loss self-biased circulator at 40 GHz: Influence of temperature

A study of a very low-loss mm-wave self-biased circulator as a function of temperature is proposed. This device presents, at room temperature and without magnets, maximum insertion losses of 0.52 dB in a 4.1-GHz bandwidth centered at 39 GHz. The evolution of the performances between 22 and 115°C is presented and discussed in view of the modifications of the static magnetic properties of the ferrite in this temperature range.