Research And Design Of The Compact Plane Ultra-wideband Antennas

The ultra-wideband wireless communications technology developed in recentyears in the wireless communication in the history of great sign-ificance for short-distance high-speed pulse communication technology, high-speed, low error rate,wide bandwidth, excellent features to make it in the indoor high-speed wirelesscommunications, radar tracking, rang-ing, precise positioning guidance and othervarious areas have been a lar-ge number of applications and considerabledevelopment.Antenna for the ultra-wideband communication system requires not only hasgood frequency characteristics, the antenna has a smaller size, lower cost, simplermechanical structure in order to facilitate better integration of various types ofportable wireless communication devices. Based on the above requirements, with aplanar structure of the microstrip antenna, its unique low profile, low cost, ease ofthe outstanding features of the integrated conformal enter the horizons of scientificresearch workers, has been a great deal of attention in the related areas, and there area lot of research done. This thesis is to explore in depth the concept of differentapplications to meet the ultra-wideband communications system antenna, microstripantenna design compact multi-purpose ultra-wide bandwidth and excellentperformance, expand the depth of research and design work, design and productionof measuring a variety of compact planar ultra wideband antenna with differentfunctions.The main innovative design results are as follows:1.According to the resonant frequency of the empirical formula of rectangularmetal patch microstrip antenna and narrow working band features. The design andsimulation of the reflection coefficient of indicators with different aspect ratiostructure of the rectangular patch microstrip antenna. According to the simulationresults arrived at a different aspect ratio patch can inspire the conclusion of the electromagnetic waves with different resonant frequency to design a compact planarultra wideband antenna two different aspect ratio patch combination and theformation of gradient structure, Verification through simulation with the measureddata, these two antenna VSWR are more than129%, designed to meet theminiaturization based on the expansion of the bandwidth of microstrip antenna,Through simulation and testing, the antenna has excellent time domain and frequencydomain characteristics, far exceeding the design requirements of the UWB antenna.2.Improve the application of the concept of the existing antenna, using a coplanarwaveguide feed structure, design a small planar microstrip antenna meet not only thelong-range radio frequency identification (RFID) communication system bandwidthrequirements but ultra-wideband (UWB) system bandwidth requirements.Theantenna with the miniaturization of portable and low-cost, Relative standing wavethan the bandwidth of more than133%, can well meet the needs of two differentcommunication systems, simulation and instrument measured results show that theantenna in a similar antenna in time domain and frequency characteristics are at theforefront.3.Based to prevent the communication systems such as WLAN frequencyaliasing, resulting in unnecessary interference noise, using a coplanar waveguidefeed structure, by the introduction of different shape and structure of the gap in themetal radiator, design two planar antennas which can stop5.0GHz-5.8GHz, in thepremise of maintaining the good characteristics, the first antenna measured relativeVSWR bandwidth of more than154%, the second antenna has a smaller size, the twoantennas meet the design goals of the miniaturization.The results show that theantenna has obvious advantages in a similar antenna.Through a large number of detailed studies, completed the design work of thefive planar ultra wideband antenna models with different features andapplications.The design and study results show that the different aspect ratio structureof the patch can be effectively completed the design of microstrip antennaminiaturization of broadband. Through the introduction of the different dimensionsrelated to the wavelength of the gap on a metal radiator, can achieve resistance characteristic of the antenna.