DIGITALLY CONTROLLED TIME-GAIN COMPENSATION FOR ULTRASONIC SCANNERS

A new digitally controlled time-gain compensation (TGC) amplifier for ultrasonic scanners has been developed. The TGC amplifier features low -noise, 40 dB compensation gain and can perform full customizing of th e slope profile, thus permitting adjustable compensation for different frequency transducers and allowing particular areas of interest to be enhanced. The TGC is based on a specialized low-noise, voltage-contro llable amplifier, an 8 bit digital-to-analogue converter, and a high-d ensity 'in-system programmable' logical device. The simple design make s it possible to use the amplifier as a stand-alone unit or to incorpo rate it into existing ultrasonic equipment.