Microwave photonics (MWP) is concerned with the use of photonic devices, systems and techniques for applications in microwave, millimetre-wave, and THz wave engineering, and also encompasses the development of high-speed photonic components for microwave system applications. The field is continuing to experience significant growth, fuelled by the recent interest and development in integrated microwave photonics and microwave/millimetre-wave photonics for 5G applications and beyond.