“Just like a capacitor or a resistor, a device capable of routing electromagnetic waves is a fundamental building block in almost any circuit,” associate professor Yuanxun ‘Ethan’ Wang said. “Making it available with unlimited bandwidth would trigger a revolution in design of mobile phones, automobile sensors or even quantum computers.”
The researchers proved that a circulator — a device that sends and receives electromagnetic waves from different ports — could enable signals to be sent and received simultaneously. This could double the space on the spectrum available for chips to transfer data.
Previous generations of circulators used magnetic material, which cannot be incorporated into current microchips and doesn’t have the bandwidth for today’s devices. The prototype uses coaxial cables to route the electromagnetic waves through non-magnetic material, but the researchers are planning to build the device using silicon-based or other semiconductor materials.
The key to the design is an approach called ‘sequentially switched delay lines’, which is similar to the way trains are routed from one track to another, to allow multiple trains to enter and exit train stations without collision.
The design includes six transmission lines, all of equal lengths, connected by five switches. The switches are turned on and off sequentially to distribute electromagnetic waves and allow simultaneous transmission and reception of data-carrying signals.
The circulator is said to work from the lowest of frequencies up to radio frequencies, and might even work in the visible light part of the spectrum.
