Study On The Field And Circuit Joint Method To The Active Integrated Antenna

Active integrated antenna (AIA) is a combination of activecomponents and passive antenna. For its compact structure, low powerconsumption, light weight, low cost and high design flexibility, it has abroad application prospect in a lot of fields such as: wirelesscommunication, radio astronomy, and biomedicine. However, due to AIA’scharacteristics to combine antenna design technology and circuit designtechnology together, it’s hardly to achieve effective simulation based oncircuit analysis method or field analysis method separately. In order tohandle this problem, we study the field and circuit joint simulation methodto the active integrated antenna.This paper has mainly discussed two models for active components toimplement the field and circuit joint method based on finite-differencetime-domain method (FDTD), a full-wave time-domain simulation method.One is equivalent circuit model and the other is scattering parametermodel. Its results are briefly summarized as following.1. An interface model spanning two-dimensional multiple cells isimproved based on traditional interface model spanningone-dimensional multiple cells.2. Based on equivalent circuit model and the interface modelspanning two-dimensional multiple cells，the modified nodeapproach (MNA) is extended to analyze arbitrary multiport device.Besides, the flow chart to analyze linear and nonlinear device isgeneralized. 3. Based on scattering parameter model, two processing techniqueshave been studied: one is using inverse Fourier transformation andthe other is using numerical fitting method. The electric fieldupdating formula for multiport device with interface modelspanning two-dimensional multiple cells is developed. And amodeling for FDTD with parallel structure in z domain is proposedto match the fitting results.4. The improved interface model and solving method are applied tothe analysis of an oscillation-type active integrated antenna, whichverifies that the interface model spanning two-dimensionalmultiple cells is more accurate than the traditional interface model.