Influence of the control signal input in pinhole device (thin-film transformer)

The modulation of the output signal from a thin-film transformer was studied. This type of thin-film transformer uses a strip line and an amorphous CoNbZr magnetic film. The changes in reflection and transmission coefficients for the transformer were observed by the application of a local magnetic field using a control current. The reflection coefficient changed drastically; however, the change of the transmission coefficient was small. The effect from the control pinhole adjacent to the input strip line was larger than the effects observed from other control pinholes. Two types of thin-film transformer with two control pinholes were prepared. The local magnetic field near the input and output pinholes can be adjusted by the polarity and intensity of the control current. It was demonstrated that the characteristics of the thin-film transformer were controllable by a local magnetic field.<>