The Research Of UWB Antenna And Radar Antenna

The antenna is a device which converts guided waves to free space electromagnetic waves and is an essential part of any communication system.Since the advent of UWB (Ultra-Wideband) technology, it has been received widespread attention and enormous amount of research. There are many advantages such as a great deal of channel capacity, good time domain analytical skills etc. With the rapid development of radar technology, there has been a lot of deveploment prospect and market demand, such as security access control systems, anti-collision vehicle radar system. So, UWB antenna and radar antenna have strong research. This paper mainly expounds the design and research of different antennas which meet different performance requirements in UWB system and radar system. The main work and innovation are as follows:Firstly, face to the UWB Location System, three kinds of Vivaldi antennas are designed and fabricated. A compact Vivaldi antenna is designed by etching trapezoid slots at outer edges of antenna and adding grating elements. The size of compact Vivaldi is 39×45×0.8mm3 and the measured bandwidth is 11.6GHz (2.9-14.5GHz) under the condition of S11<-10dB. The simulated gain is 5.5?7.8dBi at the full UWB. In order to reject the WLAN signal in UWB band, the notched Vivaldi antenna with capacitively loaded loop (CLL) resonators is proposed. The notched band is 5-5.9 GHz. A high gain Vivaldi antenna (40×50×0.8mm3) is designed by laoding dielectric and inproved the impedance matching at low-end frequency band with diamond slot stub. The measured bandwidth is 11.3GHz from 2.9 to 14.2GHz under the condition of S11<-10dB. The simulated gain is 5.5?9dBi at the full UWB band. The measured gain is 5?7.6dBi from 3 to 5.8GHz.In addition, the high gain Vivaldi antenna has a good end-fire radiation and group delay performance. The simulated and measured results of three Vivaldi agree well.Secondly, in view of the demand of 78GHz automotive radar system, the three different structures of wilkinson power divider are designed with good amplitude-phase consistency in feeding network of antenna array. Besides, the transition structure of grounded coplanar waveguide (GCPW) to microstrip line(MS) is researched and designed to achieve connection between the microstrip antenna array and chip circuit.Finally, for requirement of phase control in vehicle radar, two transmitting antenna including 2×8, 4×8 antenna array and two way receiving antenna are designed. Transmitting and receiving series-fed microstrip antenna array are designed Dloph-Chebyshev amplitude weighting to decrease low sidelobe level(SLL). The simulated bandwidth of 2×8 antenna array is 0.9GHz (77.5?78.4GHz)and SLL is less than -19dB in phi=0° and phi=90° plane. The simulated gain is 14.3dBi at 78GHz. The simulated bandwidth of 4x8 antenna array is 1.3GHz(77.3?78.6GHz), SLL is less than -15dB in phi=0° and phi=90° plane, the simulated gain is 17.6dBi at 78GHz. The simulated bandwidth of two way receiving antenna is 1GHz from 77.5?78.5GHz, SLL is less than -18dB in phi=0°and phi=90° plane, the simulated gain is 14.4dBi at 78GHz.