New Full Duplex Radio Chip Transmits and Receives Wireless Signals at Once

A new wireless chip can perform a feat that could prove quite useful for the next generation of wireless technology: transmitting and receiving signals on the same frequency, at the same time with the help of a single antenna. This approach instantly doubles the data capacity of existing technology though is not yet capable of power levels necessary to operate on traditional mobile networks.

more…

Are they transmitting back in opposite phase?

Apart from this being a handy development, something about it seems to tie in with measuring a system without destroying it as referred to in another thread.

> These signals are usually coordinated in one of two ways: time-division duplex, in which a transmitter and receiver take turns broadcasting on the same frequency, and frequency-division duplex, in which the transmitter and receiver broadcast on separate frequencies at the same time.

True. Was working for CSIRO on use of phase multiplex, rather than frequency or time. But that was one way (for optical fibre communications). Another multiplex method is to use polarisation.

> designing elements called circulators built of magnetic materials

Never heard of them.

> silicon transistors on the face of a CMOS chip in an arrangement that reroutes signals as they are captured by both the transmitter and the receiver in order to avoid interference. “You essentially want the signals to kind of circulate in a clockwise sense,” It also helped to use an echo-cancelling receiver that the lab also pioneered. This receiver solves the classic problem that transmitted signals tend to “echo” back into a receiver when a full duplex radio is in operation.

I know about the echo problem. It was first solved by radio engineers working on radar during WWII.

mollwollfumble said:

> designing elements called circulators built of magnetic materials

Never heard of them.

They’re used extensively in microwave and higher frequency applications.

btm said:

mollwollfumble said:

> designing elements called circulators built of magnetic materials

Never heard of them.

They’re used extensively in microwave and higher frequency applications.

Ta, like this I suppose, that sort of makes sense of the “clockwise” in the original article. two types “ferrite” or “waveguide”. Nope, still don’t understand the physics involved.