Input impedance calculation for a cylindrical microstrip antenna fed by a microstrip line

We consider the problem of excitation of a cylindrical microstrip antenna fed by a cylindrical microstrip line. The problem has been solved by the moments method in the spatial domain using a new representation of the Green’s function. In the model proposed, a cylindrical microstrip line of finite length is attached to the patch and is considered as its part. The so-called lumped delta generator is chosen as the excitation source. At the first stage, current distributions on the patch and in the microstrip line are found by solution of the integral equation. Then using the well-known relations of the transmission-line theory and the equivalent-scheme method, we calculate the reflection coefficient in the microstrip line and the antenna input impedance. Patches of different shapes are discussed. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 51, No. 3, pp. 223–233, March 2008.