Improved MMIC active filters based on passive LC resonators with active negative resistance circuits

A new GaAs MMIC active resonator employing negative resistance compensation for the passive inductor has been designed. The power consumption has been minimised, and sensitivities to parasitic effects and supply voltage variations have been reduced. In the light of the study carried out in this paper, the new resonator has the potential to achieve significantly lower noise figures than active inductor based filters, providing the passive components have sufficiently good quality factor. A prototype 2.4 GHz resonator was fabricated with the GMMT F20 MMIC process. Measured results show that a maximum power of 9.5 dBm can be handled, whilst drawing only 27 mW from a 3 V supply