The Design And Research Of Stop Band Characteristics UWB Antenna

Ultra-wideband (UWB) systems have been expanding at a stupendous rate since the Federal Communication Commission (FCC) of the United States allocated the spectrum3.1-10.6GHz for commercial use in2002. As an important part of the communication system, the performance of antenna will directly affect the performance of the entire system. Therefore, the researches on UWB antennas to meet the requirements of the system application are meaningful and valuable.This paper is composed of two parts. The first part briefly introduces the concept of UWB and characteristic of UWB communication technology. A brief description of the history and research trends of the UWB antenna is given and the UWB microstrip patch antenna is focused. Then the main performance parameters, design methods, notch characteristics and theoretical analysis methods of the UWB antenna are described.The second part is the antenna designs. Firstly, a novel UWB microstrip patch antenna with a deformed rectangular metal radiating patch and a U-shaped ground is proposed. To achieve UWB characteristic, the offset-fed structure, metal arms on the ground, corner cut on patch are introduced to make good broadband impedance match. Simulation results show that the proposed antenna a bandwidth3.1-10.8GHz for S11<-10dB. Then by adding a U-shaped parasitic element on the side of microstrip feed, triple notched frequency bands of3.2-3.6GHz for Worldwide Interoperability for Microwave Access (WiMax),5.1-5.9GHz for Wireless Local Area Networks (WLAN),9.5-9.9GHz for X band are achieved. Simulation results show that the length and width of parasitic element determine the notch bands.Two proposed antennas were fabricated. A good agreement between the simulated and measured results is observed. And the proposed antennas have good radiation performance.