Fastest IC reports 670-GHz operating frequency

Fastest IC reports 670-GHz operating frequency

In the last few years, transistor technologies have improved to the point that solid-state amplifiers operating above 300 GHz ( 0 MAX , a good practical rule of thumb is to choose a transistor with an fMAX 50% to 100% higher than the target operating frequency of the circuit.

In the past few years, a Northrup Grumman group has developed both InP HEMT and HBT technologies with an fMAX >1 THz and 0.62 THz, respectively. This implies that the current upper limit for amplifiers lies between 0.5 and 0.67 THz with the current generation of HEMT transistors and between 0.3 and 0.4 THz for HBT transistors. (The technical paper is available at http://tiny.cc/ec87w.)

Summary of Northrop Grumman high-frequency transistor current and next-generation performance

Developed at the company’s Simon Ramo Microelectronics Center under a contract with the Defense Advanced Research Projects Agency’s (DARPA) Terahertz Electronics program, a new performance record more than doubles the frequency of the fastest reported IC. Dr. William Deal, THz Electronics program manager for Northrop Grumman’s Aerospace Systems sector, says the amplifier is the first of its kind operating at 670 GHz.

These devices could double the bandwidth, or information-carrying capacity, for future military communications networks. They will enable more-sensitive radar and produce sensors with highly improved resolution. A variety of applications exist at these frequencies, with present scientific needs for low noise amplification and local oscillator chains for radiometry, atmospheric sensing, and spectroscopy.

Solid-state power amplifiers operating at these frequencies would also have immediate impact in lowering the dc power consumption of local oscillator multiplier chains.

Paul O’Shea