Direct current tunable noise suppressor using sub-micrometer patterned permalloy films.

A tunable noise suppressor at gigahertz frequency using sub-micrometer patterned Permalloy (Py) loaded coplanar waveguide transmission line is presented. The transmission line consists of 100 nm thick Py patterns on top of 0.9 μm thick gold lines. Measured results show that the stop band frequency of the noise suppressor is changed from 4.8GHz to 6GHz depending on the aspect ratios of Py patterns. Variation of the gap in between Py patterns changed the stop band frequency from 4 GHz to 6 GHz. Furthermore, a novel way of tuning the stop band frequency of the noise suppressor by using an external direct current is reported. By applying 150mA direct current along the transmission line, the frequency is changed from 6 GHz to 4.3GHz. The measured results of 1.5% pass band loss, 2° transmitted signal phase distortion, and 3 dB extra return loss of the designed noise suppressor are demonstrated. Noise suppression frequency and the magnitude of signal attenuation can be further improved by increasing the thickness of Py or using multi-layer Py. [ABSTRACT FROM AUTHOR]