MMIC gyrator bandstop filter with ultra-wideband tuning

This paper describes the first monolithic microwave integrated circuit bandstop filter using an inverted gyrator design. Operating up to 3 GHz it also represents the highest reported frequency application of a gyrator filter design. New active bias configurations were developed to achieve a stable gyrator response and assessment of the filters´ tuning speed and control voltage requirements has shown its suitability for digital control in applications requiring frequency agility. The individual MMICs are capable of tuning a 3%, -30 dB attenuation bandwidth, over greater than an octave, and a series combination of two MMICs have a tuneable stopband from 0.7 to 3.3 GHz.