A method to implement a square-rooting circuit is described. The
proposed circuit employs operational transconductance amplifiers
(OTAs) as the only active elements. The implementation technique is
based on an electronically variable resistor formed by the OTA,
where the magnitude of the resistance is controlled by the output
current, to provide the square-rooting function. The proposed scheme
can operate with both a voltage input and a current input signal. The
purpose of the circuit is emphasised in terms of simple configuration,
high accuracy and low cost. Experimental results showing the circuit
performance are presented.