A new design concept for wideband frequency-tunable and high-order MMIC microwave active recursive filters

This paper describes a new original microwave filter design concept using recursive principles and fully integrable in MMIC technology. To validate this technique, a 7 GHz fixed center frequency filter with 2% bandwidth and a tunable filter with 2.5 GHz tuning range around 8 GHz have been successfully implemented employing a 0.2 μm GaAs P-HEMT monolithic technology. A multicellular approach, using a cascade association of first-order recursive cells, is also described. A tunable two-pole filter has then been realized by a cascade association of two tunable one-pole filters.