基于超宽带测量设备设计与实现的多路径AOA识别
Abstract This thesis proposes an indoor Ultra wideband (UWB) channel measurement technique for highly directional antenna and multiple input multiple output (MIMO) scenarios. When there are two or more paths reaching the receiving antenna at the same time, it is multipath scenarios. Multipath propagation will cause constructive and destructive interference, and phase shifting of the signal. So it is challenge to estimate the Angle of Arrival (AOA) in the multipath scenarios. Ultra wideband technique has a lager bandwidth and high resolution，which are noteworthy. Antenna impulse is another considerable question, which will have a significant impact on the channel information. Design and performance of Vivaldi antenna array has been presented. A number of beam patterns have been measured and stored by vector network analyzer (VNA) in anechoic chamber. However, the interference among antennas will cause antenna coupling and Unreliable estimation of AOA. So another UWB antenna: Dielectric rod antenna has been introduced in this thesis. Also a mechanical rotational system has been proposed for Dielectric rod antenna to estimate AOA. On the one hand, this method can prevent interference to reduce the antenna coupling. On the other hand, just one antenna need to be used, the size of the antenna array has been reduced. This paper also proposed a method which makes it possible to include the antenna properties in the UWB channel models and extract the channel information from a multipath environment with UWB antennas. The presented technique has a considerable accuracy to estimate the AOA.7488
Keywords Ultra-wideband Antenna Design AOA Estimation Contents
1 Introduction 1
1.1 UWB history 1
1.2 UWB antenna . 2
1.3 Channel measurement 2
2 Theory 3
2.1 UWB channel measurement technique . 3
2.2 Highly directional UWB antenna 5
3 Antenna Design 7
3.1 Vivaldi antenna array design . 7
3.2 TEM Horn antenna design 8
3.3 Dielectric rod antenna design 10
3.4 Feeding network design 12
4 Experiments 16
4.1 Vivaldi antenna test in anechoic chamber . 16
4.2 Vivaldi antenna test with metallic reflector . 16
4.3 Time domain simulation of Vivaldi antenna and Dielectric rod antenna 17
4.4 Channel Measurements for Antenna Deembedding 19
4.5 Antenna properties comparison . 23
4.6 Difference of LOS and NLOS components . 24