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A novel, model-based technique for finding the impedance and sensitivity of the ultrasonic planar immersion transducer in a pulse-echo setup is proposed. The resultant sensitivities from the proposed method agree well with that obtained from a three-transducer method used in calibration studies.

Cylindrical specimens may be tested advantageously by using grazing-incidence interferometry. A multiple positions test in combination with rotational averaging has recently been used to separate the surface deviations of the specimen from the interferometric aberrations. To reduce the measuring time and to check whether the results are reliable, a second procedure is now investigated, which uses the principle of the multiple positions test to determine quantities proportional to the difference quotients of the surface deviations. After numerical integration, the results can be compared with those obtained previously by rotational averaging. The measurement principle is described, and calibration results are presented.

The characterization of FluoSpheres as an internal fluorescent pressure calibrant in diamond anvil cell between 0.1 MPa and 2 GPa is reported. The effect on fluorescence of various physical and chemical parameters such as pH, temperature and salinity is investigated.

A determination of the ruby high-pressure scale is presented using all available appropriate measurements. Calibration data extend to 150 GPa.

We present the theory and application of a novel calibration system for millimeter and microwave polarimeters. The technique is a simple extension of the conventional wire-grid approach, but employs a thin dielectric sheet rather than a grid. The primary advantage of this approach is to obtain a calibration signal that is only slightly polarized, which can be beneficial for certain applications such as astronomical radiometers that measure very low levels of polarization, or systems with a small dynamic range. We compare this approach with other calibration techniques and discuss its successful use in the calibration of the polarization observations of large angular regions experiment, designed to measure polarization in cosmic microwave background radiation. Index Terms--Calibration, microwave receivers, polarization, radiometry.

Efficiency measurements at 8.45 and 32 GHz X- and Ka-bands) have been carried out on a new 34-meter-diameter beam-waveguide antenna now in use at the NASA/ JPL Goldstone Deep Space Communications Complex. The use of portable test packages enabled measurements at both the Cassegrain and beam-waveguide focal points. Radio sources (quasars and Venus) were used as calibrators, and updated determinations of flux and source size correction were made during the period of the measurements. Gain and efficiency determinations as a function of elevation angle are presented, and the effects of the beam-waveguide system and antenna structure are clearly seen. At the beam-waveguide focus, an 8.45-Ghz peak efficiency of 72.38 percent was measured; at 32 Ghz, 44.89 percent was measured.

Polarization consistent basis sets are described for the elements He, Li, Be, B, Ne, Na, Mg, Al and Ar. The basis sets for Li, Be, Na and Mg are defined based on energetic analysis and the performance for atomization energies is comparable for those systems composed of the elements H, C-F, and Si-Ar.

The quantitative study of the high power ferromagnetic resonance (FMR) saturation response for thin Permalloy films and theoretical analysis of the relevant Suhl processes over the full FMR profiles are presented.

An analytical method for evaluating proportionally constant of pickup coil is described, A comprehensive analysis of the geometric limitations for pickup coils, with emphasis on their application to long superconducting samples with both high and small demagnetization factors is also presented.

Adaptive antennas are now used to increase the spectral efficiency in mobile telecommunication systems. A model of the received carrier-to-interference plus noise ratio (CINR) in the adaptive antenna beamformer output is derived, assuming that the weighting units are implemented in hardware. The finite resolution of weights and calibration is shown to reduce the CINR. When hardware weights are used, the phase or amplitude step size in the weights can be so large that it affects the maximum achievable CINR. It is shown how these errors makes the interfering signals 'leak' through the beamformer and we show how the output CINR is dependent on power of the input signals. The derived model is extended to include the limited dynamic range of the receivers, by using a simulation model. The theoretical and simulated results are compared with measurements on an adaptive array antenna testbed receiver, designed for the GSM-1800 system. The theoretical model was used to find the performance limiting part in the testbed as the 1 dB resolution in the weight magnitude. Furthermore, the derived models are used in illustrative examples and can be used for system designers to balance the phase and magnitude resolution and the calibration requirements of future adaptive array antennas.