On the Dependence of Radiation from Microstrip Circuits upon Substrate Parameters

Radiation coupling effects in microstrip circuits usually arise when two separate circuits are adjacently mounted. Such spurious coupling is caused by radiation from discontinuities in one circuit illuminating the other. Such coupling presents a serious problem to the microwave circuit designer particularly at higher microwave frequencies where surface mounted solid state devices are widely used. This work deals with a study of the dependence of microstrip radiation on substrate parameters. A model for the radiation produced by a curved line is investigated, and then applied to a short serpent array. Test pieces on various substrates have been manufactured to confirm the validity of this model.