A MAGNETOSTATIC WAVE RADIATION IMPEDANCE OF SYMMETRICAL SLOT LINE IN SIGNAL-TO-NOISE ENHANCER

In a slot-line-type signal-to-noise enhancer for a magnetostatic wave, it is shown theoretically and confirmed experimentally that enhanceme nt can be improved by the symmetric slot-line structure with yttrium i ron garnet (YIG) films on both sides of the slot line and by the layer ed structure of high permittivity materials. It is shown that the impr ovement in the amount of enhancement requires an increased attenuation constant of the slot line caused by the conversion loss of the linear operation to the magnetostatic wave. The magnetostatic wave radiation impedance is then derived by recognizing the contribution of the magn etic flux density normal to the slot plane among the electromagnetic f ield components traveling along the slot line to the conversion of the magnetostatic wave. By means of this radiation impedance, the attenua tion constant is derived for the symmetric slot line and the slot line with a high permittivity layered structure so that improvement to enh ancement is clarified.