Integrated Amplifiers using Fully Ion Implanted InP JFETs with High Transconductance.

Monolithically integrated amplifiers have been fabricated on InP using fully ion implanted JFETs. The FETs have a gate length of 1.5 micron and a maximum transconductance of 110 mS/mm, the highest ever reported for ion implanted InP JFETs. The amplifiers utilized both a conventional direct-coupled design as well as a new symmetrical design. The conventional direct-coupled amplifier shows a maximum gain of 8 (18 dB) while the symmetrical amplifier design exhibits the same gain without DC offset regardless of the FET threshold voltage and the power supply voltage used.