Analysis of a single-mode waveguide at sub-terahertz frequencies as a communication channel

We study experimentally the transmission of an electromagnetic waveguide in the frequency range from 160 to 300 GHz. Photo-mixing is used to excite and detect the fundamental TE10 mode in a rectangular waveguide with two orders-of-magnitude lower impedance. The large impedance mismatch leads to a strong frequency dependence of the transmission, which we measure with a high-dynamic range of up to 80 dB and with high frequency-resolution. The modified transmission function is directly related to the information rate of the waveguide, which we estimate to be about 1 bit per photon. We suggest that the results are applicable to a Josephson junction employed as a single-photon source and coupled to a superconducting waveguide to achieve a simple on-demand narrow-bandwidth free-space number-state quantum channel

Power line communications systems

The purpose of this project is to determine the performance of a Power line communication connection by measuring its propagation characteristics. For power line communication to become efficient, a model of their behaviour at frequencies from 0 to 30 MHz is required. The attenuation and phase response are of particular interest. In this project, indoor cables within a building were utilized. A three core indoor cable is modeled as a two wire lumped-element model with distributed parameters. These parameters are capacitance, inductance, conductance and resistance.The predicted results, generated by MATLAB software closely matched those obtained by the measurements carried out on the 10m flat cable. The model and its results will allow communication designers to determine the optimal communication scheme for this power line channel.However, more investigation is required to determine noise characteristics and impedance mismatch in the power line network before it can be completely modeled