Design And Implementation Of Microstrip Filter In ZigBee RF Front-End Of Wireless ECG Monitoring System

Telemedicine is one of the hot issues of international concern in recent years. And wireless ECG monitoring is an important component, which is that use modern communication technology, computer technology, electronics technology, network technology to monitor patient for long time and long-distance. The activities range of the patient can be exempted from the hospital.This paper introduces homenet, wireless ECG monitoring system and every modules of the system. Much research and design of microstrip filter of ZigBee RF front-end is made. Major research work and research results in this paper are summarized as follows:First of all, a fifth-order parallel-coupled filter for this system is simulated and designed, the results of test show that the filter meet the design requirements of the indicators.Second, against the parasitic pass-band of parallel-coupled, a DGS is designed to inhibit it. The principle of DGS is detailed. Much simulation and research on non-asymmetric dumbbell-shaped and T quasi-elliptic function filter which is two of elliptic function characteristics of DGS is made with CST simulation software. On this basis, a new type of non-symmetric DGS filter is proposed, designed and produced. The results of simulation and test show that this filter has quasi-elliptic function characteristics and its stop band attenuation is deep. So this filter is very applicable to filter out the harmonics in parallel-coupled filter.Finally, this new DGS is applied in fifth-order parallel-coupled filter of homenet system. The result shows that the performance of filter is improved without increasing the circuit area.