Integrated broadband antennas for photonic-enabled millimetre-wave transmission

The scope of this doctoral thesis is within the development of advanced wireless communication links operating in the millimetre-wave frequency range, contributing in the development of key requirements, on one hand enhancing the radiated power and enabling the steering of the radiated power. This thesis presents a photonic-based approach to support high data rates and meet the requirements that are expected for next generation systems, defined for beyond 5G (also known as 6G), highly mobile steerable devices. We present advances in the design and optimization of planar antennas on low-cost laminates integrating high-speed photodiodes in hybrid fashion. We present technique for opto-electronic integration with purpose of maximising the power transfer from photodiodes to the antenna. Both the utilise uni-travelling carrier photodiode (UTC-PD) and p-i-n photodiode (PIN-PD) are utilised for this purpose. With the successful demonstration of single-element UTC-PD and PIN-PD emitters, we conduct further research to realise integrated emitter arrays. In this respect, a photonic-integrated emitter with planar phased array antennas is developed using UTC-PDs, providing radiated mm-Wave power of up to -2 dBm. We experimentally demonstrate the photonics-enabled beamsteering over a frequency range of 60 GHz to 70 GHz, with a beam scanning range of 30°. Moreover, using the phased array module, the wireless data transmission is also achieved together while performing beamsteering. As a result, this is the first of its kind system demonstration employing integrated photonic emitter, forming the basis for large-scale integrated antenna arrays for 5G systems. Additionally, we also demonstrate photonics-based terahertz source working in the J-band (220 – 325 GH) frequency. Two modules are developed by integrating a high-speed InGaAs/InGaAsP PIN photodiode in a WR-03 rectangular waveguide WR-3 package for photonic to terahertz conversion. The first device performs direct photonic to THz conversion, providing an output power of -14.4 dBm (36.3 μW). The second device, is based on a hybrid photonic-electronic technique. By photonic-electronic co-integration, the PIN-PD is coupled to a frequency multiplier chip in a single package, providing the photonic generation and frequency multiplication in the same device. To the best of our knowledge, this is the first realisation of WR-03-integrated emitter based on a PIN photodiode. Finally, thesis presents the design of ultra-wideband detectors based on Schottky barrier diodes assembled in quasi-optic package. The primary goal is to propose a design for the receivers with large baseband bandwidth, capable of operating across frequency bands in mm-Wave and THz range. A record baseband of 25 GHz is achieved using custom-built detectors. For the proof of concept, experiments are conducted using the custom-built devices capable of transmitting more than 12.5 Gbps of data signals on carrier from mm-Wave to sub-THz.I am grateful for the funding by European Union’s Horizon 2020 Research and Innovation Programme under the Marie Sklodowska Curie project FiWiN5G, with grant number 642355. I also acknowledge the financial support from European Action COST EUIMWP CA16220.Programa de Doctorado en Ingeniería Eléctrica, Electrónica y Automática por la Universidad Carlos III de MadridPresidente: Andreas Stöhr.- Secretario: Horacio Lamela Rivera.- Vocal: Ho-Jin Son