Optically reconfigurable E-plane waveguide resonators and filters

This paper presents an optically reconfigurable E-plane waveguide resonator and filter. N-type silicon dice doped with phosphorus is used as the switching element and is connected to the edge of a metallic fin. Illumination of the silicon dice allows realization of a different length of the fin, thus creating a shift in resonant frequency of the structure. Frequency tuning range up to about 5.2% is achieved for the resonator as well as the filter. Measurements on a fabricated optically reconfigurable resonator confirm the accuracy of the design procedure. Measured responses show good agreement with simulation.

Application of fractional delay filters to tune the centre frequency location of single-band sigma-delta modulators

This paper presents a novel technique for the design of narrow-band sigma-delta modulators with an embedded tunable centre frequency mechanism. This method demonstrates that the use of sum filters combined with a fractional delayer provide the flexibility of tuning the noise shaping band for any desired variable centre frequency input signal.