Measurement of direction-of-arrival of coherent signals using five-port reflectometers and quasi-Yagi antennas
ABSTRACT The measurement results of detection-of-arrival (DoA) of coherent signals using five-port reflectometers and quasi Yagi antennas are presented. The receiver operating at 2.4GHz consists of eight five-port reflectometers and a uniform linear array (ULA) of eight 2.4GHz quasi-Yagi antennas. The DoA is estimated by measuring the phase difference of signals pitched by the antenna array and by using the MUSIC algorithm associated with Spatial Smoothing Pre-processing (SSP). The phase difference is determined using the five-port technique. The measurement results show that the DoA of coherent signals are well estimated with a maximum error of 2°. In addition, we also show that it is capable of estimating the time delay and direction of arrival simultaneously using the five-port technique.
Conference Paper: Three octave six-port network for a broadband software radio receiver[Show abstract] [Hide abstract]
ABSTRACT: The six-port network has been identified in recent years as the best candidate to implement a Software Defined Radio (SDR). However, it is difficult in practice to implement a device without impairments if a broadband design is addressed. In this paper we present a three octave six-port network, covering the frequency range from 698 MHz to 5850 MHz. The six-port network is part of a SDR receiver prototype for a novel broadband mobile communications system. It has been measured with good performance.Microwave Conference (EuMC), 2010 European; 10/2010
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ABSTRACT: A novel multiplexing technique for angular estimation that avoids the use of switches and multiple RF chains is presented. The principle of operation is as simple as connecting cables of different electrical lengths to the antennas. The advantages are simplicity and fast measurements, which enables the study of time-variant channels. If the duration of the excitation signal is less than a certain limit (which depends on the delays introduced by cables and on the delay spread of the propagation channel), the technique performs a time-domain multiplexing. However, the technique is especially interesting in the case that the excitation signal duration exceeds this limit. In that case, it requires the frequency of the signal to increase or to decrease linearly in time, regardless if the variation is discrete or continuous in time. The post-processing of the receiver output used to separate the signals corresponding to each antenna is detailed in this study. Once separated, the signals can be processed with a high-resolution algorithm to estimate the direction of departure and the direction of arrival. To validate the capability of this method, simulation results and measurements in an anechoic chamber are presented.IET Microwaves Antennas & Propagation 10/2009; · 0.84 Impact Factor
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ABSTRACT: According to the characteristic of the echo of high-frequency ground wave radar(HF GWR), which is one-dimensional narrow band signal, a virtual direction of arrival(DOA) matrix is constructed at first, then the DOA of target evaluation is achieved by the method of resolving equations for two-dimensional DOA matrix. And this method bases on the redundancy information of a linear two-row array of antennae. Both the simulation process and the treatment results of measured data (in the case of low SNR echoes and short data series) are given at the end of this paper. By comparing with GPS data of the targets, the validity and practical applicability of the method in this paper is verified.Wuhan University Journal of Natural Sciences 02/2007; 12(2):289-293.