60-GHz Wideband Radio Channel Sounder
ABSTRACT This paper describes a developed wideband millimeter-wave radio channel sounder, which is based on the previously developed 2- and 5-GHz channel-sounder concept. Performance is analyzed, and examples of measurements, analysis, and comparison to lower frequencies are given. The sounder enables wideband (3-dB bandwidth of 100 MHz) measurements with continuous phase and excellent link budged without a cable connection between the transmitter and the receiver.
Conference Proceeding: Low phase noise signal generation circuits for 60 GHz wireless broadband system[show abstract] [hide abstract]
ABSTRACT: Demand for large capacity and low installation costs explains the extensive use of millimeter wave frequencies in digital wireless broadband communications. In digital wireless systems, the achievable bit error rate is strongly dependent on low phase noise in millimeter wave signal sources. The low phase noise can be achieved with frequency multiplication of high performance microwave oscillators. This study aims to reduce the size of millimeter wave frequency doublers by evaluating the spiral transmission line transformer as a means to minimize the size of the balun. As a result we developed a millimeter wave frequency doubler, which used only 0.3 mm<sup>2</sup> area on MMIC. We also present theoretical evaluation and simulation of these novel balanced frequency doublers. Furthermore, a 60 GHz frequency doubler was designed to demonstrate the frequency doublers in a millimeter wave signal source with ultra low phase noiseMicrowave Symposium Digest. 2000 IEEE MTT-S International; 02/2000
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ABSTRACT: Characteristics of wideband indoor radio channel at 5.3 GHz were defined based on an extensive measurement campaign using a wideband channel sounder with 19 ns delay resolution. Pathloss exponents were 1.3-1.5 in LOS and 2.9-4.8 in non-line of sight (NLOS). Large difference in NLOS exponents was due to different dominating propagation mechanisms in different types of building structures. The delay dispersion was characterized by cumulative distribution functions (CDF) of the RMS delay spreads, the values for CDF=0.9 varied from 20 to 180 ns in different setups in an office building and large hall environments. The correlation functions of the radio channel in spatial and frequency domains were extracted. Small scale models for five typical indoor scenarios were developed using tapped delay linesIEEE Transactions on Antennas and Propagation 09/2001; · 2.33 Impact Factor
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ABSTRACT: This paper describes three-dimensional (3D) radio channel measurements at the base station site in an urban environment. We introduce a measurement concept which combines an RF switched receiver array and a synthetic aperture technique and allows full 3D characterization of the channel. Additionally, dual-polarized patch antennas as array elements enable full determination of the polarization properties of the impinging signals. We describe measurements at over 70 different transmitter positions and three receiver array sites with different sectors and antenna heights. Our results show that the received energy is concentrated within identifiable clusters in the azimuth-elevation-delay domain. We demonstrate that the observed propagation mechanisms are mainly determined by the environment close to the base station. Street canyon propagation dominates also when the receiver array is at or even above rooftop level with the studied measurement distances. Thus, the azimuth spectrum at the BS site is fairly independent of the location of the mobile. Signal components propagating over the rooftop are often related to reflections from high-rise buildings in the surroundingsIEEE Transactions on Antennas and Propagation 03/2002; · 2.33 Impact Factor