San Diego (CA) - Unveiled today at the International Solid-State Circuits Conference, a silicon-based amplifier for future operation in the 70 GHz to 110 GHz range has been demonstrated. The silicon project may eventually allow for data transfer rates at up to 10 Gbps over distances of up to one kilometer.




James Buckwalter, an assistant professor in the Department of Electrical and Computer Engineering at UC San Diego's Jacobs School of Engineering, invented the amplifier and named it the Cascaded Constructive Wave Amplifier.



He says, "Cascaded constructive wave amplification is a new circuit architecture that can push silicon into new operating regimes near the fundamental limits of Moore's Law and allow the ultra high data rates that the millimeter wavelength range of the electromagnetic spectrum offers. We're exploring how silicon can play a role at frequencies exceeding 100 Gigahertz. Silicon has the advantage of allowing inexpensive integration of microwave and now perhaps millimeter wave components."



This area of the EM frequency spectrum has not been of great commercial use despite its desirable properties. This has historically been due to the high cost of creating tranceivers which can operate in this range. The new silicon-only solution not only reduces costs, but allows for extremely high mass production. The image shown below is only 310 µm by 1000 µm.





The new silicon-based amplifier marks progress toward high capacity wireless communications systems that will operate at millimeter wave frequencies (70-110GHz) and could provide data transfer rates as fast as 10 Gigabits per second over a kilometer. Toward this goal, the new amplifier provides both high gain (the ability to increase the volume of a signal) and high bandwidth (the ability to do it over a broad range of tones). It has a direct transmission line path from the input to the output that carries electromagnetic waves -- undisrupted -- across the surface of a silicon chip. Amplification "stages" along this transmission line boost the signal power by monitoring the signal amplitude and generating feedback in just trillionths of a second, feedback that injects additional energy in phase to the signal. The amplifier provides record-breaking gain of 26-30dB at 100GHz and allows wave propagation along the chip surface. Credit: UC San Diego Jacobs School of Engineering