A simple, innovative design scheme can double the bandwidth of cellular and Wi-Fi
A group of engineers from the University of Texas at Austin say they have solved the half-duplex problem of receiving and transmitting radio signals, thanks to the creative use of the circulator. A circulator is a circuit in which a radio signal is transmitted through a chain of ports in such a way that a signal supplied to the first port exits through the second, to the second through the third, and so on. The inventors proposed a circuit without moving parts and inexpensive and easy to manufacture. In the future, it will be possible to integrate it not only into Wi-Fi routers, but also into smartphones. About it writes the journal Nature
Cellular networks and Wi-Fi networks have one fundamental problem - they work on the principle of half-duplex communication. At one point, a device can either transmit data or receive it - but not simultaneously. If you try to do this at the same time, the interference between the signals makes it impossible to work with them. Circulators have long been used to implement full duplex in expensive communications equipment. Classical circulators use permanent magnets and ferrite alloys, and therefore have a large weight and dimensions.
Texas engineers created a circulator without any magnets, the prototype of which has a size of only 2 cm. Industrial production and further developments can lead to a reduction in the size of the device by orders of magnitude. The new circulator works in a similar way to the classical way, but its effect of magnetic displacement of the electromagnetic wave is replaced by the effect of a traveling wave rotating inside this ring device. Due to the absence of magnets, magnetic cores and the presence of electronic control, the operating frequency of the new circulator can be tuned in a very wide range right during its operation, which is impossible to do with classical magnetic circulators. It turns out that the new circulator can simply double the network bandwidth at no particular cost.