A Novel CMOS Tunable Transversal Active Filter Adaptable to Temperature Variations and Circuit Elements Tolerance

In this paper, a three taps transversal filter for working at C-Band was designed. This filter was designed in SiGe BiCMOS 0.35 μm technology. A tuning section, which was implemented by combination of RLC devices and a DC voltage (Vt) with the range of changing 0-2V was designed and added to the filter structure and made it tunable. This new proposed filter has a high flexibility in tuning the central frequency between 2.4 to 3.4 GHz and also in tuning gain. By these two important capabilities, this filter can adjust its performance with unwanted conditions, which make filter not to operate in the desirable mode. Temperature variations and circuit elements tolerance were two cases which their effects on filter operation were studied and finally it was explained that how filter denies their undesirable effects on its performance.