First Experimental Demonstration of Photonic Time Crystal Amplification Using Varactor-Modulated Microstrip at 1 GHz

This paper presents the first experimental validation of photonic time crystal (PTC) amplification at 1 GHz. PTCs are artificially engineered periodic structures that manipulate electromagnetic properties across both time and frequency domains. We implement a varactor-modulated microstrip transmission line to realize a temporal momentum bandgap enabling signal amplification without the need of conventional amplifiers. The prototype achieves 25 dB peak gain at 1.015 GHz with low modulation power, and a 1-dB compression point of -30 dBm. This is the highest experimentally verified frequency for PTC amplification to date. The combination of tunable gain, low power consumption, and simple fabrication positions PTCs as a promising technology for compact, energy-efficient RF systems.