10th U6+ Consortium of African Universities International Conference

The generation of photonic microwave (PMW) signals with high frequency, low noise level and high power is essential for application in areas that require signals with high power for longer transmission, high signal to noise ratio (SNR), immunity to interference by electromagnetic waves and with precise control on the power, frequency and bandwidth of the signals. A number of electronic approaches for generating photonic microwave signals face a number of challenges which includes high noise level arising from the optoelectronic devices, interference by electromagnetic waves, low frequency and power with limited bandwidth of the output signals. This paper presents experimental results on photonic microwave signal generation using two techniques. The first which applied the concept of frequency mixing and direct modulation of the heterodyned coherent signals. The experiment generated photonic microwave signals with the modulating frequencies ranging from 200 MHz to 1200 MHz. Single microwave signals ranging from 480 MHz to 780 MHz were successfully generated. The photonic microwave signals generated using this technique exhibit signal to noise ratio ranging from 26.03 dB to 36.35 dB. The second technique aims at frequency shift by tuning polarization to generate new frequencies which generated photonic microwave signals at 0.25 GHz and 0.75 GHz representing the up and down conversion with the shift from 0.25 GHz to 0.75 GHz coming as a result of change in polarization by 450. The results of this work demonstrates great potential of generating single microwave signals with low noise level using frequency mixing and frequency up and down conversion with high quality output signals which are suitable for application in microwave communication systems and the related fields of technology.