Terahertz metamaterial modulators based on wide-bandgap semiconductor lateral Schottky diodes

Abstract

With the advent of 6G communications and the constant quest for more bandwidth in wireless technologies, the use of frequency bands lying in the terahertz spectrum becomes inevitable. Efficient high-speed modulation and demodulation techniques are necessary for the development of future terahertz communication systems. However, the speed of state-of-the-art terahertz modulators is limited to MHz-GHz; therefore, far away from the requirements of practical high-speed communication systems. In this work, we discuss that lateral Schottky diodes in wide bandgap semiconductors can enable simultaneous high-speed modulation (intrinsic cut-off frequency > 100 GHz), large modulation depth (>10dB), and low-loss (∼1.5dB) in a metamaterial configuration. These devices are lateral and thus do not require complex semiconductor or electromagnetic design or fabrication. Therefore, the proposed modulator design approach can unlock the potentials of the terahertz band for future 6G wireless communications.