This paper describes the design of a phase shifter with electrically adjustable parameters employing only one voltage differencing gain amplifier (VDGA) and one floating capacitor. This circuit requires no external resistors, resulting in a resistorless design and a low component count. The proposed circuit implements a first-order all-pass filter response with electronic control of its…

We have suggested an architecture of the second-order all-pass active RC-filter (ARCF), based on three differential difference amplifiers (DDA’s), which provides full set of amplitude-frequency responses (AFR’s) (low pass filter (LPF), high pass filter (HPF), band pass filter (BPF), rejection filter (RF)). We have given the basic equations, which allow ARCF’s. The results of computer…