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NIST has upgraded its measurement capability of noise parameters on low-noise amplifiers with a variable termination unit in the 1 to 12.4 GHz range. Such a unit allows improved time efficiency in the noise-temperature measurements used to de-embed noise parameters of amplifiers. We present measured results for noise parameters of a low noise amplifier in the frequency range of 8 to 12 GHz.
A calibration system of a 3.5 mm coaxial power sensor was implemented using transfer standards with 7 mm coaxial or K-band waveguide input connectors. A 7 mm-3.5 mm or WR42-3.5 mm adapter was used to form a combined transfer standard. The effective efficiency of the combined transfer standard was obtained. The 3.5 mm coaxial power sensor was calibrated using the well-known direct comparison method...
This paper presents transmittance spectra and complex magnetic permeability and dielectric permittivity parameters of pure and mixed powdered barium ferrites, nickel zinc manganese ferrites and nickel cobalt copper ferrites in a broad-band millimeter wave frequency range. A free space, millimeter wave magneto-optical approach has been successfully employed for precise characterization of ferrite materials...
An overview of the development and performance of a current transformer with current ratios of less than unity at the National Research Council of Canada (NRC) is described. A prototype current transformer with a current ratio of 0.025A/1A that can be operated at up to at least ten times the rated current (secondary current up to ges 10 A), with ratio errors of less than 20times10-6 in both magnitude...
The present status of an international attempt of several national metrology institutes to determine the Avogadro constant with a relative standard uncertainty better than 2ldr10-8 is presented. To this end, a world-wide collaboration has been set up to produce a 5 kg 28Si single crystal with an enrichment factor greater than 99.985%. Technological steps for the growth of the 28Si single crystal,...
A compact and simplified 13C2H2 optical frequency standard is currently under development at NPL. The standard uses an inexpensive, commercially available 20 mW DFB diode laser, which is stabilized to line P(16) of the nu1 + nu3 band at 1542 nm in an experimental arrangement which dispenses with the need for an enhancement cavity. Preliminary stability and reproducibility data will be presented.
We report on accuracy test results on the comparison of two different types of optical frequency combs, each of those referenced to a microwave frequency standard and an optical frequency standard. One of those combs is based on a mode-locked erbium-doped fiber laser and the other is based on a Ti:sapphire femtosecond laser. The comb comparison was carried out by measuring an absolute frequency of...
The international community started recently to look for a new way to define the Kelvin. Different experiments around the world have begun. This presentation will describe very briefly the four different techniques currently used for the redetermination of k, namely the measurement of the speed of sound in pure helium-4, the determination deduce of the Doppler profile of the linear absorption line,...
Two fiber-based frequency combs were compared at 633 nm. An offset laser was locked to a frequency comb, and the locked laser was measured with another comb. Consequently, the frequency uncertainty of the combs was less than 3 times 10-16 at 10 000 s averaging, which is sufficiently lower than the uncertainty of UTC.
This paper demonstrates two approaches to determine the absolute mode number of the comb line for a semi-automatic optical frequency counter based on two mode-locked fiber laser combs. In the first approach, two laser combs were operated at three different repetition rates with two of them are so close to each other that their beating mode numbers are the same. In the second approach, the laser combs...
The calibration of apparent charge, which can be traced to AC voltage and capacitance, for partial discharge(PD) calibrator is discussed. The methods of fast sampling measurement of peak-to-peak amplitude for step voltage by digital multimeter and the arithmetic in the automatic measurement of apparent charge by digital oscilloscope are focused on. Then, other factors, such as impulse waveform and...
The International Avogadro Coordination aims at determining the Avogadro constant by measuring the molar mass, lattice parameter and density of a 28Si single crystal. As the temperature dependent quantities are measured in different apparatuses, the consistency of the temperature measurements has to be proven. An electronic temperature reference and a standard platinum resistance thermometer (SPRT)...
This paper describes the analysis of a measurement comparison of resistance standards, using a method of constrained least squares. The approach is based on [1] which provides a general framework for the analysis of measurement comparisons independent of their complexity.
We have measured both the 0.01 Hz (quasi-DC) and 1.0 kHz value of a room temperature air-gap capacitor as a function of environment (pressure, temperature, humidity). A huge difference in the humidity dependence was discovered in both measurements. This proves that surface layers containing adsorbed water have a significant effect on the frequency dependence of the capacitance value of air-gap capacitors.
We show that it is possible to fabricate a device, based on a superconducting nanowire, to demonstrate the existence of coherent quantum phase slip (QPS). If coherent QPS exists, this device will form the basis of a new type of quantum current standard capable of closing the metrological triangle.
In this paper, plans and progress of a Finnish collaboration towards direct closure of the quantum metro- logical triangle are presented. The experimental concept and the present status of the main components, including two possibilities of the single charge transport device, Bloch oscillating transistor (BOT) based null detector, and a thin-film cryoresistor, are described.
An APMP key comparison of power gain for Ka-band (26.5 GHz - 40 GHz) horn antennas has been being carried out between KRISS and NMIJ. This paper describes the comparison and its progress so far. Measurement results will be presented at the conference.
The design and correction factor evaluation of a WR-15 (50 to 75 GHz) rectangular waveguide microcalorimeter is presented. This new microcalorimeter will be the US national standard for power from 50 to 75 GHz. It can measure the effective efficiency of a wider variety of transfer standards than can the previous microcalorimeter. It has also been designed so that its correction factor can be experimentally...
A general method initially developed for the estimation of the S-parameters measurement errors caused by non-ideal calibration standards, is applied for the correction of the reference impedance of 7- term through-attenuator-network (TAN) calibration procedures such as thru-attenuator reflect (TAR). Deviations from ideal calibration elements are measured on-wafer using the multiline TRL method and...
An accurate RF attenuation measurement, with small mismatch effect, is achieved without source and load being matched to the line impedance. Insertion loss measurements to the DUT and to the DUT fitted by quarter-wavelength lines are carried out, then the attenuation is obtained simply, unrelated to the source and load reflection coefficients. Experiment results on two 20-dB attenuators at 11 GHz...
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