As the frequency increases, due to limited bandwidth and high noise, processing the microwave signals using the digital components such as frequency synthesizers, analogue-to-digital converters and RF up/down converter, becomes highly difficult. Today’s fully digitized radar systems works in sync with other subsystems only up to few GHz. Further, generation of extremely stable RF signals particularly at upper–side of radar frequency band with available technology is almost impossible today or highly expensive. Thus, the development of a new technology, based on photonics, to generate a wide spectrum of highly-stable RF signals (up to mm waves) and transport, detect/measure ,and process those microwave signals is very much essential to mitigate the limitations of existing RF technology. In this survey paper, we reported the outcome of a thorough literature survey on the up-to-date worldwide developments in the field of photonics radar technology. The reported survey address the maturity of photonics radar technology in four different aspects namely (i) generation and transportation of RF signal, (ii) processing of microwave signal in photonics domain, (iii) detection and measurement of photonics microwave signal and (iv)Photonics radar architecture(v) Photonics based software defined radar (vi) Photonics based MIMO radar; to explore/understand the full-potential of the photonics radar technology to meet the demand of neat-future next generation radar requirements.