A slot-line MSW signal-to-noise enhancer

A broadband MSW signal-to-noise enhancer is described which is based on a slot-line transducer that can efficiently launch MSW onto a metallized surface of a YIG film. The effect of metallizing the YIG surface is to increase the bandwidth, from the approximately 1 GHz previously demonstrated with a microstrip device, to approximately 3.5 GHz in the slotline device. Ideally the spacing between the YIG film and the metal layer should be zero, however, in practice a residual non-uniform spacing of approximately 7 μm resulted in a decreased bandwidth. Enhancement of greater than 5 dB was measured, at a power level of +20 dBm, over a 2.2 GHz bandwidth with a threshold power level of 0 dBm.