Linearly tunable CMOS VDBA design

摘要

A CMOS voltage differencing buffered amplifier (VDBA), whose transconductance gain can be varied linearly by the external DC bias current, is described in this paper. A current squaring circuit is used for biasing the transconductance amplifier with improved wide-input dynamic range, yielding electronically and linearly tunable transconductance. The application of the proposed VDBA in realizing a phase shifter circuit is also suggested. Simulations on the circuits are performed using PSPICE program to confirm the theory and demonstrate the circuit performances.