The Research Of Dual-band/Broadband Printed Antennas And Automotive Anti-collision Radar

With the rapid development of modern microelectronics technology and the continuous progress of integrated circuit technology, the wireless communication device tends to be miniaturization, modular, multifunctional and intelligent. Antenna is the radio frequency front end of modern communication system. Its size and performance will directly affect the communication quality of the whole system.While having the advantages of small-size, easily integrated and light-weight, the printed antenna also has the shortcoming of low-gain and narrow-band. Due to these defects, the application of printed antenna in multi-band and wide band communication is limited, which is not conducive to the multi-function of device.This paper studies the dual-band / broadband printed antennas and automotive anti-collision radar antenna, meanwhile puts forward some new antenna structure models, which provide a reference for engineering design. In this thesis, the main contents are as follows:(1)Using slotting, slot loading, bending and other techniques, we deform the structure of microstrip antenna and design two dual-frequency microstrip printed antennas. By using photolithography technology in the 2.6GHz main circular radiation patch etched on a pair of "1" slot, we get a dual-band antenna that works in 2.6GHz and 5.8GHz; Using the bending technology, the center frequency of 900 MHz monopole antenna and 1800 MHz monopole antenna are printed on the same piece of dielectric slab, so we get a dual-band monopole antenna which can be applied to the GSM/DCS band.(2)Using the method of frequency band broadening and reasonable selection of dielectric substrate, we design two broadband printed antennas. One is the broadband leaf-shaped antenna which can work in WIFI 5.0GHz and WLAN 5.8GHz, the other is the wineglass broadband antenna which can work in 2.45 GHz, WiMAX 2.6GHz and WLAN 5.8GHz.(3)Based on the rectangular patch antenna elements with grooves, we design a vehicle collision avoidance radar antenna with low loss, high gain and omni-directional radiation characteristics. Choosing the proper feeding unit, a compact microstrip antenna array is formed, which has 4 elements, low loss, high gain and isolation.