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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 bandwidth1,2. Recent research has focused on system demonstrations3,4, as well as the exploration of new components for modulation5, beam steering6 and polarization control7. 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 microwave8 or optical9 regimes, enables independent control of both the centre frequency and bandwidth of multiplexed terahertz channels.

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Figure 1: Schematic of the multiplexer.
Figure 2: Free-space-to-waveguide coupling.
Figure 3: Multiplexing of terahertz signals from two transmitters.
Figure 4: Tuning the channel frequency with plate separation.
Figure 5: Spectrum allocation tuning with waveguide geometry.


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The authors thank K. Reichel for contributions. This work was supported by the US National Science Foundation and the W.M. Keck Foundation.

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All of the authors contributed to the conception and design of these experiments. R.W.M. and N.J.K. built the set-up and collected and analysed the data. All authors contributed to the discussions and to the writing of the manuscript.

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Correspondence to Daniel M. Mittleman.

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The authors declare no competing financial interests.

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Karl, N., McKinney, R., Monnai, Y. et al. Frequency-division multiplexing in the terahertz range using a leaky-wave antenna. Nature Photon 9, 717–720 (2015).

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