Network synthesis applied to the design of tuned optical front-ends for microwave lightwave systems

An analysis of the tuned optical front-end noise performance of lightwave receivers modulated by microwave carriers shows that under certain load conditions partial noise cancellation may be obtained. The Letter presents a method of synthesising a tuning network between the photodiode and the receiver input stage which minimises noise over a selected microwave bandwidth. The synthesis, carried out with lumped elements, makes no a priori assumptions on network topology, and an example is given of the design of a 4-6 GHz tuning network realised using an HEMT transistor.