A new chip by Columbia University researchers uses a circulator made of silicon transistors to reroute signals and avoid interference from a transmitter and receiver that share the same antenna. The chip enables them to work around the principle of Lorentz Reciprocity, in which electromagnetic waves are thought to always travel along the same path both forward and backward.
If this technology work well, the promise is that this technology instantly doubles data capacity and could eventually be built into smartphones and tablets.
Looks interesting. I expect to see how well this works in real life – is it practical?
Traditionally, electronic devices have used several techniques to allow full duplex communications service to work. Here are few techniques that have been used before (usually combination of several of those approaches):
- two separate antennas for transmitter and receiver physically separated enough (so transmitter power does not overload receiver)
- transmitter and receiver operated on different frequencies (filters can be used to separate signals)
- circulators and directive couplers on antenna connection (usually big bulky components with limited attenuation)
- use time division multiplexing so that transmitting and receiving happens at the different time in controlled manner fast enough that the data flow feel enough “real time and full duplex)