Frequency-division multiplexing in the terahertz range using a leaky-wave antenna

The idea of using radiation in the 0.1-1.0 THz range as carrier waves for free-space wireless communications has attracted growing interest in recent years, due to the promise of the large available bandwidth(1,2). Recent research has focused on system demonstrations(3,4), as well as the exploration of new components for modulation(5), beam steering(6) and polarization control(7). However, the multiplexing and demultiplexing of terahertz signals remains an unaddressed challenge, despite the importance of such capabilities for broadband networks. Using a leaky-wave antenna based on a metal parallel-plate waveguide, we demonstrate frequency-division multiplexing and demultiplexing over more than one octave of bandwidth. We show that this device architecture offers a unique method for controlling the spectrum allocation, by variation of the waveguide plate separation. This strategy, which is distinct from those previously employed in either the microwave(8) or optical(9) regimes, enables independent control of both the centre frequency and bandwidth of multiplexed terahertz channels.