An efficient microwave characterisation of PIN photodiodes

This paper investigates for the first time the transmission line behaviour of a PIN photodiode at microwaves frequencies. Original theoretical models are developed for the complex propagation constant of this structure and compared with measurements carried out at U.C.L. It is shown that the classical methods found in the literature for characterising the propagation of slow waves are not efficient in this case. The general variational principle previously developed by the authors is used in a new way. Results are obtained which closely agree with the experiment. The assumptions made on the trial fields used in the variational formulation are confirmed by a fullwave analysis of the fields in the multilayered structure using the method of lines.