Hybrid analysis/design method for active integrated antennas

The paper presents a new hybrid analysis/design scheme where electromagnetic full wave and nonlinear circuit solvers are used in conjunction with an improved Kurokawa (1969) analysis. The full wave solver is the finite-difference time-domain (FDTD) method and is used to extract the scattering parameters (S-parameters) of all passive components and to predict the radiation patterns. The extracted S-parameters are then used in a CAD nonlinear circuit solver to characterise the device line and find an operation point. Note that the effects of the higher order harmonics on the operation point of this active antenna are taken into account by means of the harmonic balance algorithm. To validate the proposed method, an oscillator-type active antenna working at 2.019 GHz is fabricated and tested. It is shown that the calculated and measured results, such as operation frequency and radiation patterns, agree very well