Research On Coplanar Waveguide Feed Antenna And Design On Its Miniaturization

The coplanar waveguide antenna has the thin section, small size, light weight, and a flat structure. It is easy to obtain linear polarization, circular polarization, dual-polarization, multi-band and other functions. Based on these advantages, the coplanar waveguide antenna has been widely used in the modern wireless communication. With the rapid development of antenna technology, the miniaturization design of the antenna has become a trend.Therefore, how to effectively broaden the high band bandwidth of the coplanar waveguide antenna, reduce the return loss and miniaturized become a hot topic.Firstly, this paper introduces the research background and the current research status of the coplanar waveguide antenna and its miniaturization.Secondly, some basic parameters of the antenna are introduced such as VSWR, return loss, and polarization patterns and so on. The theory of the antenna is summarized such as the method of moments(Method of Moments), FEM(Finite Element Method) and FDTD method(Finite-difference Time-domain). And the theoretical basis of the coplanar waveguide antenna miniaturization is analyzed; an effective way is found to achieve the miniaturization of the antenna- to increase interdigitated capacitance.And then, the ground and the radiating structure of the coplanar waveguide antennas are optimized. One is that the rectangle ground structure is optimized as the trapezoid structure: the return loss of the center frequency is reduced from-13 dB to-16 dB, and the frequency band is also extended range from 7GHz-12 GHz to5GHz-12.5GHz; the other is that the radiating of the antenna is optimized using the opening slot technology:single slot structure and double slot structure. Compared with the trapezoid antenna, the return loss of single slot antenna is reduced further from-16 dB to-18 dB, and the frequency range is further extended to 2GHz-13 GHz.However, the measured results of the double slot antenna show that its performance is not satisfied.Finally, the miniaturization of the antenna is designed using the interdigitated capacitance technology. The interdigitated capacitance is designed in the ground structure, which realizes the miniaturization of the antenna successfully. The size of the antenna is reduced from 29mm*29mm to 22mm*22mm, and the overall size is reduced by 24%. Compared with the single slot antenna, the bandwidth of the miniaturization antenna decreases slightly, but still the frequency band is extended range up to 9GHz-12.5GHz.Finally, this paper is summarized, and the innovation and the improvement of the research are proposed.