History of MMICs

Updated May 6, 2005

On this page we will collect information on the evolution of MMICs. Why? Because we love this stuff! Remember class, this is going to take some audience participation, so send us some material!

Let's start with the world's first MMIC, which was an amplifier. In 1975, a paper published by Ray Pengelly and James Turner entitled "Monolithic Broadband GaAs F.E.T. Amplifiers" sealed their fate as the inventors of the MMIC. Working at Plessey, their little single-stage amplifier provided 5 dB of gain at X-band using 1 micron optically-written gates. They used computer optimization to design their lumped element matching structures, which included capacitors and inductors, but no DC blocking on the input/output. Backside processing had not yet been worked out, so the FET's source was grounded externally.

Let's let Ray Pengelly continue the story...

"The picture you are showing is not the actual first MMIC - that was a 2nd iteration with higher gain and lower noise figure.

The CAD program was Compact via GE satellite with home-grown lumped element models. The design was done at Plessey Applied Research Labs, Roke Manor and fabricated at Plessey Central Research Labs, Caswell. It was Comsat, so in Washington DC I think -- too many years ago!?

I have some of the original hand-drawn MMIC layouts dated March 3, 1975. These were then transferred to Rubilith and then photo reduced and multi-upped to a mask -- GaAs substrates then were small, (1" or less) irregularly shaped pieces so you didn't get many circuits per run. I remember the celebrations in the clean room at Caswell when we got 6 circuits all working at DC on one occasion!!