Microstrip filtenna at ISM band

Abstract

This thesis describes a design and simulation of microstrip Filtenna at ISM band (Industrial, Science and Medical) applications with the frequency of 2.45 GHz. In terms of multi-operation antennas such as filtering capability, this Filtenna design is a good candidate for implementation in future multiband radios, cognitive radio (CR), and software defined radio (SDR). This approach is a great utility since it allows the wireless terminal to operate in ISM frequency bands. The filtering antenna (Filtenna) provides an additional filtering action which greatly improves the noise performance and reduces the need for filtering circuitry in the RF front end. Over the past view years, there are many filteringantenna structures have been proposed, studied and reported. However the previous designs have contributed some contra issues to be eliminated, such as large size and wide signal transmission lose. To meet these requirements, one of the most significant types of multifunctional antennas (MFA) has been presented in this thesis. Compact microstrip antenna with filtering capabilities (Filtenna) is proposed in this thesis. A rectangular microstrip antenna has been designed based calculations and the previous studies. On the other hand, parallel-coupled bandpass filter is designed. The CST simulator has been used to design simulate and optimize the antenna and filter separately. Then, they are combined to become a filtenna. The performance of the filtenna is then simulated. The simulation result shows that the return loss of the antenna itself is –11.37 dB at 2.45 GHz. The filter has –16.76 dB return loss while the insertion loss is –2.3 dB. Then the filtenna return loss is –18.3 dB. The proposed filtenna is suitable to be used in any communication system at 2.45 GHz frequency which needed a compact system.