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As millimeter-wave(mmWave) 5G communication is actively developed, the importance of measurement to verify its quality is emerging. In the mmWave phased array antenna, a phase deviation may occur between antennas due to manufacturing tolerances of active/passive elements, which may degrade beamforming performance. We proposed a method for measuring the element-level phase through an electro-optic(...Show More
Frequency extension of the RF power standard using a thermal voltage converter (TVC) has been accomplished down to 1 kHz. To measure the effective efficiency of a thermoelectric power sensor (PS), a reference TVC with a built-in tee is employed. A modified TVC measurement system enables us to automatically measure the dc substituted power of the PS as well as the RF voltage of the reference TVC in...Show More
This article presents a standard field generation system with an antenna for the calibration of a Ka-band electric-field probe. We constructed a measurement system having capability of not only rotating the azimuth angle of the probe but also changing the separation distance between the antenna and the probe. As a result, the orientation and separation distance of the probe can be suggested for mi...Show More
A useful calibration method utilizing the SOLR, ‘Unknown Thru’, is introduced. The proposed method is expected to be very useful for the applications where long cables should be used with a VNA such as antenna measurements. With the proposed method very long or lossy cables can be used as long as one-port calibration can be carried out at the cable ends. Compared to the classical SOLR it has much ...Show More
To calibrate Ka-band electric field probe standard field generation system with antenna was implemented. For traceability we measured the associated quantities such as power, impedance, and attenuation of each component consisting of the field generation system. Evaluation of uncertainty in components providing traceability to the system was completed. The system is expected to generate standard f...Show More
To measure the calibration factor or the effective efficiency of thermoelectric power sensors (PSs) in the low frequency range a reference thermal voltage converter (TVC) is employed. A modified RF voltage measurement system enables us to transfer the RF voltage standard of the TVC to the PS. The standard RF power is obtained from the RF voltage at the input of the PS and the measured conductance ...Show More
A measurement system for a millimeter-wave (mm-wave) antenna is presented here. The topologies of RF subsystems for antenna measurements are reviewed, and the optimum topology for a far-field antenna measurement range for mm-wave antennas is proposed. This topology minimizes the losses of both the Tx and local oscillator (LO) signal paths. In order to verify the proposed topology, a W-band antenna...Show More
A comparison of antenna characteristics (i.e., power gain, radiation pattern, and reflection coefficient) for 700-1100 MHz/R(1.7-2.6 GHz)-/X(8.2-12.4 GHz)-band horn antennas has been performed between Korea Research Institute of Standards and Science (KRISS) and four domestic participants including private companies and public institutes. In this comparison, all participants have used the gain com...Show More
In this paper, we propose an antenna measurement system using distributed LOs(local oscillators) and mixers. The sensitivity and dynamic range of the antenna measurement system improved, because the proposed system minimizes the losses of RF and LO cables due to short cable lengths. As a result of measuring the insertion loss of antenna pairs using the proposed system, the sensitivity was improved...Show More
In free-space material measurements, it is known that the minimum size of a planar MUT (Material Under Test) should be larger than three times the beam waist of the antenna to neglect diffraction effects at the edges of the MUT. To hold the MUT, its holder has the aperture size larger than the minimum MUT size. In the case of metal MUT holders, even though their aperture size is larger than three ...Show More
In this paper a method to improve the measurement uncertainty from the inaccurate representation of the equivalent capacitance of a short monopole antenna element is proposed for the equivalent capacitance substitution method (ECSM). And some consideration about the model formula of the effective height of a monopole antenna is also discussed.Show More
In this paper we propose a method to characterize waveguide shims, which are being used in almost all calibration kits for waveguide connectors and also used as impedance standard in Thru-Reflect-Line (TRL) calibration, for their length and aperture width and height. Also given are preliminary uncertainty analyses for the electrical characterization of the length, actually the phase shift through ...Show More
This paper presents a new method for the determination of the complex permittivity of thin sheet dielectric materials that are flexible and elastic. Instead of the traditional method to install a doughnut shape sample in the transverse plane used in transmission line methods, most widely used methods for broadband permittivity measurements, a thin sheet sample is installed onto the outer conductor...Show More
A comparison of antenna parameters (i.e. antenna gain, radiation pattern and reflection coefficient) for R-band (1.7–2.6 GHz) and S-band (2.6–3.95 GHz) standard gain antennas has been performed between Korea Research Institute of Standards and Science (KRISS) and seven domestic participants including private companies and public organizations. Its purpose, as a proficiency test program of the ‘Ant...Show More
This paper presents a minimally invasive measurement method for a highly resonant cavity by using electro-optic detection. The interior fields, with respect to the external incident ones, were investigated by numerical simulation and experiments. The discrepancy of the cavity's shielding effectiveness, measured by a monopole antenna and an electro-optic probe, is discussed. The electro-optic metho...Show More
This paper presents a new method for the determination of the reflection and transmission characteristics of dielectric materials that are the parameters for the calculation of the complex permittivity using the Nicolson-Ross-Weir (NRW) method. In transmission line methods, most widely used methods for broadband permittivity measurements, the NRW method gives a stability problem for low-loss diele...Show More
This paper presents a method of vector network analyzer calibration using `Thru-Short-Delay' for one-port measurements, which is expected to give a comparable accuracy to the TRL technique as it does not accompany cable movements. It uses a one-port VNA (Vector Network Analyzer) to avoid cable movements with `OSL' (Open-Short-Load) calibration standards, which are widely used for one-port measurem...Show More
This paper presents a method to measure the (equivalent) reflection coefficient of signal sources. To make highly-mismatched power detectors, are used stepped impedance lines whose scattering parameters can be accurately obtained from dimensional measurements of their structures such as the radii of the inner and outer conductors and their lengths. Since there is no need to use a Tee or splitter t...Show More
The direct comparison technique using a transfer power standard with an adapter and its uncertainty are considered. A waveguide thermistor mount with an appropriate waveguide-to-coaxial adapter serves a new combined coaxial power standard. In order to obtain the effective efficiency of the combined standard, the phase as well as the magnitude of the adapter scattering parameters have to be known. ...Show More
A system to measure the noise temperature (NT) of noise sources is implemented in the frequency range of 18-26.5 GHz for the case where noise sources commercially available have only one nominal NT, e.g., 9500 K being equivalent to 15-dB excess noise ratio. For the Y-factor method, two noise sources, i.e., a noise source and another with a radio-frequency attenuator, serve as the standard noise so...Show More
A cryogenic 7-mm coaxial noise standard at 77.35 K has been designed and constructed. A ferrite composite-matched termination was used as a thermal noise source in the frequency range of 4.5–18 GHz. The noise temperature of the noise standard has been determined by measuring the temperature distribution and attenuation constant of a thermally isolated coaxial line and the attenuation of the output...Show More
We have recently developed a standard step attenuator, composed of 10 steps of build-up chain of power measurement and operating from 10 MHz to 18 GHz. Each step shows a nominal attenuation of about 9 dB and an expanded uncertainty of 0.0018 dB at 30 MHz. The overall system has a dynamic range over 90 dBShow More