Saulius Kazlauskas

Broadband Method for the Determination of Small Sample's Electrical and Dielectric Properties at High Temperatures

A model for a measurement circuit consisting of a telescopic coaxial transmission line with the sample placed in the gap of the central conductor has been developed and a measurement method, based on this model, was tested. To determine the samples electrical properties, the method requires the measurement of the two-port scattering matrices of the short-circuited line, the line with one calibration sample, and the line with the sample to be measured inserted. The model takes into account the thermal elongation of the measurement line and can be used for measuring electrical properties of materials at high temperatures in the megahertz and gigahertz ranges. This model also reduces the influence of parasitic reflections in the measuring coaxial line on the measurement results and takes into account a complicated distribution of the electromagnetic field in the measuring capacitor without solving a complicated electrodynamics problem.

SINTERING OF OXYGEN ION CONDUCTIVE CERAMICS AND THEIR ELECTRICAL PROPERTIES

Oxygen ion conducting ceramics (Sc2O3)0.1(ZrO2)0.9, (Sc2O3)0.1(CeO2)0.01(ZrO2)0.89 and Ce0.9Gd0.1O1.95 were sintered from powders with different specific surface areas. The produced ceramics were studied by scanning electron microscopy and impedance spectroscopy methods. Impedance spectroscopy measurements were performed in a wide frequency range of 10 Hz–3 GHz at temperatures up to 900 K in air. Temperature dependences of bulk and total ionic conductivities of ceramics were investigated. High bulk ionic conductivity of the order of 1 S/m at 900 K for 10ScSZ and 10Sc1CeSZ ceramics was achieved. Total ionic conductivity for both types of 10GDC ceramics was of the order of 0.1 S/m at 700 K.

FBMC Modulation as a Possible Co-existence Facilitator for LTE Mobile Networks in 800 MHz Band

ABSTRACT This paper proposes filter bank multicarrier transmission technique (FBMC) as means to minimize adjacent band interference from long-term evolution (LTE) user equipment operating in the frequency band 792–862 MHz to short-range devices in the band 863–870 MHz. Main FBMC benefits are presented through comparison with reference case of orthogonal frequency-division multiplexing. The key advantage of FBMC modulation in reported electromagnetic compatibility studies is derived from its low out-of-band leakage, which guarantees minimum harmful interference level between stations using adjacent channels. The problem was evaluated in two aspects: first, theoretical analysis using minimum coupling loss method, complemented with statistical Monte-Carlo analysis (using SEAMCAT software tool) in order to verify results obtained in theoretical approach.