Use of VNAs for wideband propagation measurements

Street, A.M.; Lukama, L.; Edwards, D.J.

doi:10.1049/ip-com:20010639

Cited by 48 publications

(34 citation statements)

References 12 publications

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“…Using a vector network analyzer (VNA) arrangement [9], the complex transmission parameter, S 21 (f ), is measured between f l = 3.1 GHz and f h = 10.6 GHz at N f = 1601 frequency points. The bandwidth is thus W = f h −f l = 7.5 GHz and frequency resolution is ∆f = 4.685 MHz.…”

Section: System Model and Channel Measurementmentioning

confidence: 99%

Impact of Bandwidth on Small-Scale Fade Depth

Malik

Allen

Edwards

2007

IEEE GLOBECOM 2007-2007 IEEE Global Telecommunications Conference

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Abstract-This paper investigates the impact of channel bandwidth on fading in wireless channels using indoor measurements. The variation of channel energy over a local region is examined for narrowband, wideband and ultrawideband (UWB) channels, and the corresponding fade depth is evaluated. The relation between bandwidth and fade depth is then captured with a simple dual-slope model. The effect of antenna polarization and line-ofsight blockage is also investigated. We observe that the fade depth initially falls rapidly with bandwidth, reaching 4 dB at 1 GHz, but further reduction in fading with bandwidth is much slower.

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Section: System Model and Channel Measurementmentioning

confidence: 99%

Impact of Bandwidth on Small-Scale Fade Depth

Malik

Allen

Edwards

2007

IEEE GLOBECOM 2007-2007 IEEE Global Telecommunications Conference

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“…Thus, information on the electromagnetic properties of the areas where measurements have been made, provide valuable insight in appreciating the capabilities and limitations of UWB technology for indoor applications. A number of researchers [2][3][4][5][6][7][8][9][10][11] have studied UWB channel characteristics in commercial, industrial or in house environment using frequency-domain measurements. The author in [12] presents an overview of UWB propagation channels and their characteristics, summarizing the basic theory and techniques for measurements and modeling.…”

Section: Introductionmentioning

confidence: 99%

Channel Measurements and Modelling in a Military Cargo Airplane

Spiliotopoulos¹,

Kanatas²

2010

PIER B

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Abstract-The results of an ultrawideband (UWB) measurement campaign carried out in a Hercules C-130 military cargo airplane are presented. The environment encompasses several metallic surfaces resulting in a large number of multipath components. Path-loss factor n representing the distance dependence of the channel path-loss is calculated for various frequency centers and bandwidths. A pathgain calculation model based on the concept of seperability of distance and frequency variables is proposed and comparison to measurements is given. Furthermore, time dispersion parameters, namely mean excess delay and root mean square (r.m.s.) delay spread are examined and their dependence on transmitter-receiver antennas separation is investigated. A power law is then employed to model the relation between the number of multipath components and the r.m.s delay spread. The temporal correlation between adjacent path amplitudes is found to be negligible. A modified Saleh-Valenzuela model is invoked to describe the clustering of multipaths, where a different power decay factor is used for the rays of the first cluster as opposed to subsequent clusters. Moreover, the Weibull distribution models the small scale channel fading with a lognormally distributed shape parameter. The average values of this parameter imply severe fading conditions. Finally, simulation results of the proposed statistical model are compared to measured data demonstrating reasonable agreement.

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“…Basically, the problem stems from the fact that coherent receivers with a wide bandwidth allow significant noise power to enter the receiver, which limits the system's dynamic range. Measurement systems employing a single vector network analyzer have been proposed for indoor channel characterization efforts [32,33,34,35]. With this approach, coherent, wideband, propagation measurements can be performed over relatively short distances.…”

Section: Introductionmentioning

confidence: 99%

“…With this approach, coherent, wideband, propagation measurements can be performed over relatively short distances. To maintain coherence, the signal generated by the network analyzer is relayed to the distant transmitter via long RF cables or optical links [35]. While this approach performs well in an indoor setting, it is impractical for an outdoor setting where multiple sites need to be accessed, often behind significant foliage.…”

Section: Introductionmentioning

confidence: 99%

Compact Reconfigurable High-Frequency Ultrahigh Frequency (HG-UHF) Antenna

Sarabandi¹

2003

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Public Keporting burden Idr mis collection of information is estimated to average 1 hour per response, including the time for reviewing instmctions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comment regarding this burden estimates or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services. Directorate for information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and The goal of this research effort was the development of computer algorithms for the predication of radio wave propagation in forest or Vegetated environments. In addition, recognizing the need for measured data sets for validation of such modesi, two measurements Campaigns were conducted, one to determine path loss for near-Earth propagation and one which utilizes a unique, synchronized, long-range measurement system (the system has been tested to over a kilometer, and in principle will work over longer ranges), developed for this project, and which allos for the evaluation of both pathless and frequency decorrelation. Since the start of the project in May, 2001, significant progress was made towards achieving the project goal. A physics-based methodology was used, in which the actual physical scenario of a given propagation problem or environment is modeled. A description of this physicsbased methodology and why this approach is applied is given In the final technical report. The impact of this effort on FCS and related programs is then discussed, followed by a brief summary of the project accomplishments. Completed work is then described. Where noted, expanded and detailed discussions of several of the developed algorithms is later given. Significant progress has been made in the development of a set of simulation tools for the prediction of channel effects on a radio signal propagating in a forest or vegetated environment, as well as in developing measurement techniques and systems for validating such tools. Complex and rigorous mathematical formulations have been developed and combined with efficient computer algorithms to produce a set of simulations tools which characterize and predict channel effects to a degree of accuracy and generality not previously available.To date no general tools are available to system design engineeTS, which would give them the ability to accurately assess the performance of a complex communication system and evaluate the channel capacity. An accurate and general model of the propagation channel is critical for evaluating system performance in terms of system parameters such as the tradeoff between radiated power and signal processing, modulation schemes, diversity schemes, etc., and such a tool would give the system engineer a-priori knowledge of optimum system configuration, without the need for costly prototypes.--Having recognized this deficiency, the goal of this research effort was the ...

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Use of VNAs for wideband propagation measurements

Cited by 48 publications

References 12 publications

Impact of Bandwidth on Small-Scale Fade Depth

Impact of Bandwidth on Small-Scale Fade Depth

Channel Measurements and Modelling in a Military Cargo Airplane

Compact Reconfigurable High-Frequency Ultrahigh Frequency (HG-UHF) Antenna

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