[backwoods-engineer]

But now, Stanford researchers have developed the first wireless radios that can send and receive signals at the same time.

Absolute and utter bullcrap.

As an RF engineer and amateur radio operator, I can tell you that this has been done for DECADES. Just one example: the 10 GHz repeater built by the San Bernadino Microwave Society. They used spatial diversity to transmit and receive on the same frequency at the same time.

Dang, I hate how journalists (and idiot professors) explain things like this.

[Erasmus]

Correct me if I'm wrong, but I doubt that Stanford would put out this press release unless they had a technique for sending and receiving simultaneously and on the same channel. In other words a single-channel repeater (and single-channel simultaneous T-R radios to go with it).

I recall reading claims like this back in the 1970s from a British firm doing defense work. I think it was Plessy.

The problem is, of course, to try to null out the transmitted signal to get at the received signal coming back to you on the same transmission line. This would mean a null of at least 130 decibels on the transmitted signal.

You'd have to start with the mother-of-all directional couplers and then back that up with some black magic DSP on the front end of the receiver.

Even changing reflections of the transmitted signal off nearby objects would bollix the null, requiring some extraordinary technology to maintain it.

But therein may lie an interesting application for 'continuous-wave' radar.