Dielectric Probe Kit Research Articles

INVESTIGATION OF THE CHARACTERISTICS OF BARIUM STRONTIUM TITANATE (BST) DIELECTRIC RESONATOR CERAMIC LOADED ON ARRAY ANTENNAS

We investigated a dielectric resonator ceramic microstrip patch antenna. The antenna was formed using barium strontium titanate (BST), which had a dielectric constant of 15. A new approach, i.e., the use of a high temperature dielectric probe kit, was used to determine the dielectric constant of BST. A computer simulation technology (CST) microwave studio was used to simulate the BST array antennas, taking into consideration the dielectric constant. We also measured the gain of the antennas loaded with two-, four- , and six-element arrays of the BST antenna and found that the gain of a six-element BST array antenna was enhanced by a gain of about 1.6dB over the four-element BST array antenna at 2.3GHz. The impedance bandwidths of these BST array antennas for voltage standing wave ratio (VSWR) < 2 were in the application ranges,

Analyses of dielectric properties of fertilizers (urea and diammonium phosphate) in aqueous solution at different temperatures in microwave frequency.

This paper reports experimental results which have been carried out for understanding the behavior of dielectrics in the form of mixer of fertilizers and water content at wide frequency range in different temperatures. A simple and rapid measurement (reflection method) was used in determining the dielectric response at microwave frequency. The dielectric constant and loss have been measured in frequency range from 1 to 40 GHz with different temperature according to environment. The measurement procedure has been performed by dielectric probe kit using 50 GHz Performance Network Analyzer (PNA). The samples were prepared by mixing different fertilizers in water according to the Department of Agriculture. The different fertilizers (urea and diammonium phosphate) were taken from the market. The experimental work shows the dielectric behavior of solution of fertilizers and water in temperatures. The amount of water and fertilizers content were taken according to the Department of Agriculture. Keywords: Dielectric constant, dielectric loss, reflection, dielectric probe kit.

Complex Permittivity Measurements of Rainwater in the 0.5–26.5 GHz Frequency Range

Modeling electromagnetic wave propagation in rain requires knowledge of the complex permittivity of rainwater. In response, we measured the complex permittivity of rainwater in the 0.5-26.5 GHz frequency range using an Agilent Technologies 85070E Dielectric Probe Kit and an Agilent N5242A-400 Vector Network Analyzer. Rainwater samples were collected in Graz (Austria) and Kototabang (Indonesia). The results obtained were found to differ slightly from those of Ray's and Liebe's models. However, the difference in the complex permittivity of rainwater between the measurement and model results exhibits very small biases in the Mie extinction coefficients ( <; 0.01%).

An analysis of the microwave dielectric properties of solvent-oil feedstock mixtures at 300–3000 MHz

Microwaves can be a more efficient method than traditional thermal treatment to deliver the energy required for heating in solvent-oil extraction due to its volumetric, direct coupling with the material. An understanding of the behavior of dielectric properties of solvent–feedstock mixtures is important for designing and optimizing any microwave-based extraction process. In this study rice bran and soybean flour were mixed separately with four different solvents (methanol, ethanol, hexane and isopropanol) at different ratios (1:2, 1:1, 2:1 w/w). For the samples mixed with ethanol, the dielectric properties were measured at 23, 30, 40 and 50 °C, while for all other sample-solvent mixtures experiments were performed at room temperature. Dielectric properties were determined using a vector network analyzer and dielectric probe kit using the open-ended coaxial probe method in the frequency range of 300 MHz to 3 GHz. Results from the study indicate that dielectric constants were dependent on frequency and were strongly influenced by temperature, mix ratio and solvent type. The dielectric loss of all mixtures except those with hexane (which were virtually zero) varied with frequency and temperature, solvent type, and mix ratio. Most of the results presented are emphasized at 433, 915 and 2450 MHz, frequencies allocated by the Federal Communication Commission (F.C.C.) for microwave applications. The results of the study, presented here for the first time to our knowledge, will help in selection of appropriate solvent, mixing ratio and frequency for designing microwave-assisted oil extraction systems.

An Analysis of Dielectric Properties of Synthetic Ballast Water at Frequencies Ranging from 300 to 3000 MHz

Ballast water presents an important vector for introduction of aquatic invasive species in the coastal waters around the world. Currently there are no established technologies proven to completely eliminate this problem due to the particularities of the ballasting and de-ballasting operations (extremely large volumes of water, efficiency at destroying macro and micro organisms, environmental issues associated with chemical treatments). Continuous microwave heating presents a potential solution to this problem, but the design of suitable applicators depends on the dielectric properties of the ballast water to be processed. The study presented in this paper is focused on the dielectric properties (dielectric constant-ε’; dielectric loss-ε”) of synthetic ballast water inoculated with four organisms at seven different temperatures in the frequency range of300 to 3000 MHz. The dielectric properties of the mixtures were determined using a network analyzer and a dielectric probe kit using the open-ended coaxial probe method. Numerical analysis was performed on data collected across all frequencies involved with an emphasis placed on F.C.C. allotted frequencies of 433, 915 and 2450 MHz. The dielectric constant was relatively independent of frequency and the organism used, but it showed a remarkable decrease with temperature. The dielectric loss showed an extreme decrease with increasing frequency, marked differences between the different organisms and between different growth stages of the same organism, and a large relatively linear increase with increasing temperature.

Characterisation of materials behaviour in microwave joining of ceramics

In this paper, attempts made for optimising the process parameters of the microwave welding of ceramic materials using a ridge waveguide are presented. The dielectric constant and the loss tangent parameters are measured using a HP85070 dielectric probe kit and also a network analyzer that works in the frequency range of 500 MHz–20 GHz at room temperature. These two parameters are measured in order to understand the penetration power of the microwave, and the ability of the material to convert absorbed energy into heat. The properties of the joint such as flexural strength, grain size, composition, porosity and other related properties are compared with respect to the parent materials. From the results obtained, it can be concluded that the quality of joint produced is reasonably good, with a joint strength of 60–95% of the flexural strength of the parent material.