The measurement of the concentration of nitrates in different solutions is of interest in industrial and biomedical applications. Due to this, it is proposed to work with resonant structures manufactured with microstrip technology which were designed as dielectric permittivity sensors. These devices depend on changes in the dielectric properties of the medium, so they can detect variations in the concentration of nitrates. Depending on the dielectric properties of the sample, the electrical response will be such that changes in the response can be related to variations in the percentage content of nitrates in the measured solutions. The increase in the dissolution of calcium, magnesium and potassium nitrates in water shows a clear and notable change in the resonance frequency with which it is possible to identify the percentage level of dissolution in the samples.
A forced-mode composite resonator is used on a moisture sensor to characterize humidity percent of honey at the microwave regime. Sensors of two different shapes, one rectangular and one circular, are designed and fabricated using commercial phenolic sheets. The resulting resonant frequency of the sensor changes as a function of the humidity contained in the sample. Honey samples are placed inside small glass bottles and this foreign material is taken into consideration. Measurement results are as expected and when the effective permittivity value of the samples is too high the modes will interchange.
In this numerical work, we present some cases of transmission behavior in a power-symmetric, polarization-imbalanced nonlinear optical loop mirror (NOLM) through a three-dimensional (3D) analysis. The study has been implemented using the Jones matrices for inputs at linear and circular polarization and varying the length in the loop. The results show control over the switching power and the maximal transmission, which let us see more easily the graph visualization at the output of a scheme. However, we can determine the characteristics of the experimental operation (fiber loop, input power, angles of the retarder plates, critical power, and input polarization). These results can be used to establish regions for potential applications in optical communications such as ultrafast optical signals processing, optical switching, demultiplexing, filtering, logic gates, and pulse compression.
Using a forced-mode composite right/left-handed resonator, we designed and proved a permittivity sensor at the microwave regime. We use this sensor to measure humidity percent of honey and potatoes. The sensor resonant frequency can be modified without altering its physical length. With this characteristic a bigger frequency bandwidth can be covered. In addition to that, the second and third mode can also be used for measuring increasing even more the sensor frequency bandwidth. It can be clearly appreciated that one mode is magnetic and the other electric. Not only they differ in their amplitude but also in their quality factor. By moving the position that forces the modes, the first mode frequency value will increase while the second one will decrease. This will happen until the modes meet each other and then they will exchange places.
A reconfigurable dual-passband to single-passband filter based on highly miniaturized ring resonators is presented. The filter is designed for 448 MHz for the first band and 668 MHz for the second band as the central passband frequencies and simulations are used for enhancing the design. The filter is implemented using microstrip technology on a RO3010 substrate with thickness of 1.28 mm. The lower passband can be eliminated by just changing the location of a short. Measurements for the optional eliminated band are in good agreement with the expected values. The transmission is −3 dB at the central frequency for dual-passband configuration and −26 dB for single-passband configuration.
This paper presents several broad-spectrum sources generated by pumping a 532nm laser microchip, with 600ps pulses and various combinations of conventional thin-core optical fibers. Fibers with a core of 2.1μm, 2.5μm and 3.5μm were used; with lengths of 38m, 23.3m and 19.7m respectively. We present the results derived from experimenting with each type of fiber separately, as well as making combinations among them, obtaining broad spectrum light sources (supercontinuous light) with a spectral width of approximately 300nm and powers greater than -20dBm.
A filter which its bandpass frequency can be reconfigured is presented. Its central frequency ranges from 316 MHz to 392 MHz (22% tuning). The filter is based on a miniaturized compose right/left-handed ring resonator. The reconfiguration of its resonant frequency is implemented by shifting a short location, thus changing its effective lefthanded inductance. This is opposed to the conventional capacitance change of other reconfigurable filters. The relation short location versus central frequency is quasi-linear. The short location could be controlled by a servomotor configuration.
A reconfigurable dual-passband to single-passband filter, which is based on miniaturized ring resonators, is presented. The filter is designed for 448 MHz and 668 MHz as the central passband frequencies. Simulations are used for enhancing the design. The lower passband can be eliminated by just changing the location of a short. The filter is implemented using microstrip technology on a RO3010 substrate with thickness of 1.28 mm. Measurements for the optional eliminated band are in good agreement with the expected values. The transmission is -3 dB at the central frequency for dual-passband configuration and -26 dB for single-passband configuration.
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