Researchers have demonstrated a fully-integrated single-chip microwave photonics system, combining optical and microwave signal processing on a single silicon chip. The technology can replace bulky and power-hungry components, according to the researchers, from imec and Ghent University, enabling faster wireless networks, low-cost microwave sensing, and scalable deployment in applications such as 5G/6G communications, satellite communications, and radar systems. Modern communication networks rely on both high-speed fiber-optic links and wireless radio-frequency microwave transmission, but as demand for higher data rates and operation at higher frequencies grows, new systems need much tighter integration between these two modes of communication to overcome the struggle with signal processing complexity, high transmission losses, and power-hungry electronics. Packaged microwave photonic chip, with two high-speed inputs and two outputs, and control wires for programming the filter response and the input-output connections. The fiber array has not yet been connected in this picture. Courtesy of imec. Microwave photonics offers a promising solution by using optical technology to process high-frequency signals with lower loss, higher bandwidth, and improved energy efficiency. However, most microwave photonics systems rely on bulky, fiber-based architectures that limit scalability. In contrast, integrating microwave photonics onto a chip could enable more scalable and power-efficient systems, but early experimental demonstrations have either lacked key functionalities or required external components to achieve full performance. “The ability to integrate all essential microwave photonics components on a single chip marks a major step toward scalable and energy-efficient high-frequency signal processing,” said Wim Bogaerts, professor in the Photonics Research Group at Ghent University and imec. “By eliminating bulky external components, this technology paves the way for more compact, cost-effective solutions in next-generation wireless networks and advanced sensing systems.” The Photonics Research Group and IDlab, two imec research groups at Ghent University, and imec, created a chip that integrates high-speed modulators, optical filters, photodetectors, as well as transfer-printed lasers, to process and convert both optical and microwave signals. The key innovation in this single-chip system lies in the combination of a reconfigurable modulator and a programmable optical filter enabling efficient modulation and filtering of microwave signals while significantly reducing signal loss. According to the researchers, the combination enhances overall performance, allowing the system to handle complex signal processing tasks with greater flexibility and efficiency for a wide range of applications. The chip is built on imec’s standard iSiPP50G silicon photonics platform, which includes low-loss waveguides and passive components, high-speed modulators and detectors, and thermo-optic phase shifters for tuning the optical response. To provide an integrated light source, the researchers incorporated an indium phosphide optical amplifier (developed by III-V Lab) on the chip using the micro-transfer-printing technology developed at the Photonics Research Group (imec/Ghent University). In combination with on-chip tunable filter circuits, this allows the optical amplifier to function as a widely tunable laser, further enhancing the system’s versatility, according to team members.