Determination of size-independent effective permittivity of an overlay material using microstrip ring resonator

Abstract

shown in Figure 7 with the simulation data at the same time. The performance summary is shown in Table 1.Core structures of the dual-band SIW filter are the CSRRs and CSRs. Relatively speaking, the influences of other geometrical parameters are not obvious. So that the filter has a potential to be much smaller. As shown in the photograph from Figure 8, length of the SIW is greatly reduced, and the taper microstrips are removed. After adjustment and optimization, its geometrical parameters are: l SIW 5 9 mm, w SIW 5 12 mm, r via 5 1 mm, w via 5 2 mm, w 2 5 1.2 mm, l 1 5 3 mm, l 3 5 1.9 mm, a 1 5 0.28 mm, b 5 5.2 mm, d 5 0.82 mm, g R3 5 0.3 mm u 1 5 0.22 mm, u 2 5 0.095 mm, h 5 7.5p, t 5 3.149 mm. The geometrical size of the simplified filter is 0.118k 0 3 0.184k 0 , where k 0 is the free space wavelength at the center frequency of lower passband. Furthermore, the performance of the filter does not decline with structure simplification, as shown in Figure 8, and Table 1.Due to processing inaccuracy, there are slight differences between the results of measurement and simulation. But overall, most of them are consistent, proving that the theoretical analysis of the design is correct. CONCLUSIONA new approach to design the dual-band SIW filter is proposed in this article. By modifying the CSRRs and loading them into the SIW with the CSRs together, the compact dual-band filters perform well. The interaction between the CSRRs and CSRs is discussed, indicating the potential on the combination of those two right/left-hand structures. After simulation and optimization, the proposed dual-band SIW filters are fabricated using normal PCB process. From the results of measurement, it can be seen that the proposed filters have good frequency selectivity, and excellent band rejection, which are consistent with the simulation results.ABSTRACT: This letter describes a size-independent effective permittivity of biological tissues, using microstrip ring resonator (MRR), to evaluate the moisture content more effectively. As permittivity is depends on material density, the optimum sample size where further size variations will not change the effective permittivity are identified. Using simulation and experimental results it is found that, a sample having thickness more than 9% of substrate height (t sub ) and width greater than 18.3% of guided wavelength (k g) shows size-independent effective permittivity. Both simulation and experimental results are in good agreement (within 3%). These findings allow more effective characterization of muscles according to their moisture content. V C 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:4-9, 2016; View this article online at wileyonlinelibrary.com.

Microwave bio-sensor based on symmetrical split ring resonator with spurline filters for therapeutic goods detection

“…This is due to the increment of the effective permittivity until it reaches the asymptotic value which demonstrates the electric field penetrated into the overlay sample. The result is in the lines of earlier literature [ 24 ] that found the saturation point is about 5% of MUT thickness.…”

A Novel Symmetrical Split Ring Resonator Based on Microstrip for Microwave Sensors

“…Therefore, further increase in sample thickness will not affect the resonance frequency. This is due to the fact that all of the electric field is confined into the overlay sample and substrates which interpret the effective permittivity that increases with the height of the overlay until it reaches the asymptotic value as discussed in literature [20]. Correspondingly, this happens to the insertion loss magnitude as indicated in Fig.6.…”

“…From the results it can be observed that a small thickness causes a smaller shift from the resonator's inherent frequency. This happens because of the increasing of the perturbation when the overlay sample size is increased and more fringing fields are focused into the overlay sample as discussed in literature [19], [20]. In Fig.5., results are presented for an amount of attaining resonance shifts for each corresponding thickness of overlay sample.…”

High sensitive microwave sensor based on symmetrical split ring resonator for material characterization

“…Therefore, further increase in sample thickness will not affect the resonance frequency. This is due to the fact that all of the electric field is confined into the overlay sample and substrates which interprets the effective permittivity is increased with the height of the overlay until it reaches the asymptotic value as discussed in literature .…”