# Digital coding metamaterials with multi-modulation schemes and beam steering for intra-chip millimeter-wave connectivity

## TL;DR

This paper introduces a digital coding metamaterial that enables efficient intra-chip millimeter-wave communication by modulating signals and steering beams without traditional antennas.

## Contribution

The novelty lies in using a metamaterial to directly modulate and steer millimeter-wave signals for intra-chip communication, bypassing antenna limitations.

## Key findings

- The metamaterial converts digital control inputs into discrete phase shifts of a 70 GHz TE-mode surface wave.
- It supports modulation schemes like BPSK, QPSK, and 8-PSK, along with hybrid modulation and beam steering up to ±28°.
- The design reduces signal crosstalk and increases channel capacity and spectral efficiency in intra-chip communication.

## Abstract

In modern wireless communication systems, data transmission is achieved through the collaboration of digital modulation circuits and antennas. Digital baseband signals are first modulated in terms of amplitude, frequency, and phase of the carrier wave and then transmitted directionally via antennas. However, in intra-chip environments, the performance of on-chip antennas is fundamentally constrained by micro-fabrication and integration requirements. As a result, these antennas often exhibit low gain and efficiency and are susceptible to interference among closely spaced transmission channels. To address these limitations, we propose a digital coding metamaterial for direct signal modulation within intra-chip wireless channels, providing an alternative solution to achieve directional signal delivery without depending on the antenna’s intrinsic radiation pattern. The proposed metamateiral can directly convert digital control inputs into discrete phase shifts of a 70 GHz TE-mode surface wave, enabling post-radiation modulation as the electromagnetic wave propagates through the metamaterial. When combined with a single broadcast antenna, multiple metamaterial units can perform simultaneous, multi-directional modulation and transmissions. The proposed metamaterial supports various phase shift modulation schemes, including BPSK, QPSK, and 8-PSK. Furthermore, it enables hybrid modulation and beam steering modes, offering a beam steering range of up to \documentclass[12pt]{minimal}
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\begin{document}$$\pm 28^{\circ }$$\end{document}. The proposed metamateiral presents an innovative method for information routing in intra-chip transmission, helps reduce signal crosstalk under parallel transmission, and expands wireless channel capacity and spectral efficiency.