Millimeter wave generation techniques for future communication systems

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University LondonMillimeter-waves (mm-wave) can be an attractive candidate for providing capacity improvements beyond 5G. Since mm-wave generation is the main factor in mm-wave communication, this thesis aims to generate high-quality frequencies in the mm-wave band using a cost-effect and straightforward design. The mm-wave generation converges with the Radio over Fiber (RoF) communication system through the data transmission. A 60 GHz is generated based on carrier suppression using an external modulation method; for the first time, an inverted optical filter is used to suppress the carrier; the performance of the obtained signal worked effectively up to 10 Gb/s for 20 km. A high-quality 72 GHz mm-wave signal based on carrier suppression is generated based on the quadrupling frequency technique; the Optical Suppression Sideband Ratio (OSSR) improved by 29.1dB. The performance of the resulting mm-wave signal is compared with two optical modulators, The Electro Absorption Modulator (EAM) and Mack Zehnder Modulator (MZM), along with two different types of photodiodes Avalanche Photodiode (APD) and PIN-PD. The resulting performance of the EAM is higher than the MZM, with a Q max factor of 20. Additionally, the power of the received 72 GHz signal is improved by 35% with APD. A novel approach is introduced to generate an upper band of mm-wave frequencies through the 12 frequency tupling technique using parallel DD-MZM's only. In addition, the max Q factor of various transmission distances for the obtained frequencies is measured. The max Q factor for 300 GHz with 20 Gb/s over a 10-km transmission distance is 8.22 with a minimum BER of 1.97 × 〖10〗^ (-28). A performance of 300 GHz over free-space optics (FSO) over various distances was investigated using two FSO channel models, gamma-gamma and log-normal, with different attenuation levels. The resulting performance is highly desirable with a max Q factor of up to 80 dBm / km to a 2000-m FSO link. Therefore, mm-waves generated using the proposed designs could be implemented beyond 5G for future indoor and outdoor communication networks