On the permittivity of multilayer ferroelectric films
3
Citation
5
Reference
10
Related Paper
Citation Trend
The change characteristics of permittivity following the frequency of alternation electric field was surveyed by investigating Yam tissue.The results showed that the permittivity of the same thickness potato tissue was whole minishing by 1 V work tension.Permittivity increased with the increase of the thickness at the same frequency.Three minimal value of permittivity at the same thickness of Yam tissue came forth.The frequency with each minimal value of permittivity was constant correspondence with the increase of the thickness.
Vacuum permittivity
Cite
Citations (0)
The influence of 0.5 wt% ZnO nanoparticles fillers in the epoxy resin on the development of the complex relative permittivity has been studied. Frequency dependences of the real and imaginary parts of complex relative permittivity were measured within the frequency ranges from 1 mHz to 1 MHz by the capacitance method. The development of the complex relative permittivity of the epoxy resin and nanocomposite were analyzed by the Cole-Cole model and its various parameters were determined at various temperatures. The α- and IDE- relaxation processes were observed at the temperature measurements
Cite
Citations (2)
This paper proposes a compressed-sensing based method to estimate the relative permittivity of a material filling up a waveguide. Two monopole antennas are placed at both ends of the waveguide, and the S-parameters between the antennas are measured. Relative permittivity is estimated by applying compressed sensing to the frequency characteristics of the S21, where two-dimensional bins for distance and relative permittivity are defined to find unknown parameters. The simulation result showed that this technique can estimate the relative permittivity within a 7.3% error.
Waveguide
Cite
Citations (0)
This paper presents a simple method to measure the relative permittivity of glass-epoxy printed circuit boards (PCBs). In this method, the relative permittivity as a function of frequency is measured using an actual PCB. In order to estimate the relative permittivity, the reflection coefficient is measured with a network analyzer. The relative permittivity is calculated by observing the frequencies of the resonant cavity modes. We show that the relative permittivity of an FR-4 sample decreases from 4.3 to 4.2 at frequencies from 300 MHz to 2 GHz.
Reflection coefficient
Network analyzer (electrical)
Reflection
Cite
Citations (57)
Vacuum permittivity
Cite
Citations (0)
In our laboratory, we developed a simple estimation of the wall thickness by the UWB (Ultra Wide-Band) radar system. The described technique measures the wall thickness in the two steps. The first step is a measurement of the wall relative permittivity. The second step is a reflections localization and estimation of the wall thickness. The borders of the wall could be detected by the envelope of the received signals. The described technique calculates the signal envelope by the Hilbert transform. Moreover, the relative permittivity of the wall is estimated by the technique developed in our department as well. The effective relative permittivity is calculated from the frequency dependency of relative permittivity.
Envelope (radar)
SIGNAL (programming language)
Cite
Citations (2)
In this paper, the authors demonstrate a method of using low permittivity 3D printing materials to design all‐dielectric frequency selective surface (FSS). The 3D printing method can be used to fabricate complex structures rapidly and freely. The relative permittivity of materials used in 3D printing is in the range of ≈2.5–4.5. These low permittivity materials are usually transparent to the electromagnetic (EM) waves. In this paper, these low permittivity materials are used to realize stop band FSS to inspire the localized enhanced electric resonances and magnetic resonances by the periodic design. With the ability of using different dielectric materials with low permittivity, FSS with more functional effects may be designed and fabricated in an inexpensive and bio‐friendly way.
Selective surface
Cite
Citations (1)
The helical slow wave structure technique is discussed for measuring the complex permittivity of high-dielectric constant materials, including high-loss bio-samples. The theoretical background of the technique is presented here for measurements on high-permittivity solids, viscous dielectric samples including bio-samples, and aerosols. To prove the feasibility of the technique, ϵ and ϵ— values of the phantom muscle sample (30% gelatine + 69% water + 1% NaCI) are determined experimentally at 2·45 and 2·55 GHz in the S-band and are compared with those values obtained theoretically.
Vacuum permittivity
Dielectric loss
High-κ dielectric
Cite
Citations (3)
Complex relative permittivity, which is one of the important electrical constants of materials for electromagnetic compatibility inside and/or around building, is estimated by iteration calculation using four measurements of the magnitude of reflection coefficient from Free Space Measurement System. The estimation conducts for 1.55GHz to 6.5GHz frequency range including wireless LAN frequency, and the complex relative permittivity of the 9 kinds of interior building materials, including plaster boards and fiber reinforced cement boards are presented. The results of the work have good agreement to the previous works. The variation for frequency and samples of the complex relative permittivity also conduct for these samples. It is very important to estimate electrical constant including complex relative permittivity accurately for the efficient discussion of electromagnetic compatibility inside and/or around building. Various methods have been reported for the determination of the complex relative permittivity of non-magnetic materials, such as Resonator Method, Waveguide Method and Free Space Method. However, few works conduct for building materials, especially interior building materials. So, we estimate the complex relative permittivity for interior building materials by using four measurements of the magnitude of the reflection coefficient from the Free Space Measurement System and iteration calculation. Fig.1 shows the outline of the measurement system. Before the estimation of the complex relative permittivity, we confirm the effectiveness of the measurement system by using acrylic plate (Fig.2). Four measurements are follows, backed by a metal plate from front side (front-short), samples only from front side (front-open), samples backed by a metal plate from back side (back-short), and samples only from back side (back-open). The calculation starts to put above four measurements data and the calculated reflection coefficient by initial guess complex relative permittivity into equation (9). The calculated reflection coefficient can be conducted by using equation (1) to (8) for open and short measurement. The iteration calculation perform to minimize the value of Δ|Γ| under the certain value of the standard deviation for the complex relative permittivity, and the target complex relative permittivity should be obtained when the value of Δ|Γ| achieve to minimum. The measurement of the reflection coefficient performs for 1GHz to 13.5GHz, 501 points, 25MHz steps, and the iteration calculation for 1.55GHz to 6.5GHz, 100 points, 50MHz steps in this work. Table 1 shows samples for the estimation (9 kinds of materials and 23 samples). These samples put into standard humidifier (temperature is 20℃ and humidity is 60%) in certain days to make samples homogeneous with respect to water content. Fig.3, Fig.4 and Fig.5 show the frequency distribution of the complex relative permittivity for Fiber Reinforced Cement Boards, Plaster Boards, Sound Absorbing Boards, and Woods. The real part of the complex relative permittivity decreases for the higher frequency for all samples, and the imaginary part of the complex relative permittivity for Fiber Reinforced Cement Boards increases for the higher frequency. These results have good agreement to the work done by Rhim for the measurement of mortal and concrete from 1GHz to 20GHz and Chiba for the simulation of the concrete. And the estimated complex relative permittivity for Plaster Boards are agree to the value presented by Hashimoto by using Free Space Transmission Method. Table 2 shows the maximum frequency variation of the complex relative permittivity (the ratio to the average value) for 1.55GHz to 6.5GHz. The variation increases for the lower density. The value of the frequency variation of Fiber Reinforced Cement Board Type I and II is about 5% for the real part of the complex relative permittivity and 6-10% for the imaginary part of th
Reflection coefficient
Cite
Citations (2)
Additive manufacturing has been combined with commercially available RF materials to synthesise composite materials whose relative permittivity can be controlled. A design equation for predicting the effective permittivity of these composite materials has also been presented. The relative permittivity of the composite materials was measured by fabricating patch antennas using these materials as the substrate. It has been demonstrated that by using Taconic, polyactic acid (PLA) and air, three materials with different dielectric constants, a large and nearly continuous range of relative permittivity values, from 1.47 to 6.00, can be realised.
Cite
Citations (6)