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The optimization of the performance of optical modulators requires reasonably accurate predictive models for key figures of merit. The interleaved PN junction topology offers the maximum mode/junction overlap and enables the most efficient modulators for depletion-mode operation. Due to the structure of such devices, accurate modeling must be fully three dimensional (3D), representing a nontrivial computational problem. A rigorous 3D model for the modulation efficiency of a silicon-on-insulator interleaved-junction optical phase modulator with submicron dimensions is presented herein. The drift–diffusion and Poisson’s equations are solved on a 3D finite-element mesh, while Maxwell’s equations are solved using the finite-difference time-domain method on 3D Yee cells. The entire modeling process is presented in detail, and all the coefficients required by the model are presented. The model validation suggests

The fabrication process of a microparabolic reflector using isotropic xenon difluoride Xe F 2 etching technique is presented and analysed through this work for developing infrared antenna-coupled detectors. Although many parametric studies described the behaviour of this process in the literature, the non-linearity of the process and its dramatic dependency on the pattern definition result in great difficulties when adopting the process for developing a particular structure. The main focus of this work is, therefore, to present a detailed etching analysis as dictated in the proposed design providing the proper etching recipe according to the proposed structure design and its associated masking pattern. Deep insights into the process have been highlighted suggesting the necessity of the process assessment in terms of evaluating the three-dimensional etched volume rather than the etched depth. This will potentially solve the non-linearity behaviour and the pattern dependency problem. The optimum etching recipe yields approximately a total volume of 0.354 mm3 through the proper patterning mask. The resultant parabolic cavities have 75 and 13 μ m in their diameter and depth, respectively, as required for the proposed structure. The integration of a microparabolic reflector with such detectors will potentially enhance the specific detectivity of these detectors.

This work is on the design of a fully integrated 0.13-µm CMOS multi-standard power constrained simultaneous noise and input matching low-noise amplifier (PCSNIM LNA). The multi-standard capability is obtained via the implementation of CMOS switches. The input and output matching are fully implemented on a chip, which is uncommon when compared to the existing multi-standard LNA topologies. The multi-standard LNA is operated at 0.9, 1.8, and 2.1 GHz frequencies. The design covered wireless standards of GSM900, DCS1800, and W-CDMA applications. The multi-standard LNA can obtain noise figure as low as 1.72 dB. The third-order intercept point, IIP3, is as high as −4 dBm, while IP1dB is −10 dBm. The power consumption of the design is only 7.4 mW. This resistorless multi-standard LNA design is not just able to operate at three different frequencies but also has a comparable performance with the rest. Its merits are contributed by high linearity and low power.

In this study, MWCNTs were used as a filler for epoxy thin film composites, where the thin film was fabricated using the spin coating method. We investigated the dielectric properties of the MWCNT-filled epoxy composite, with filler loading in the range from 0 to 1.5 vol%. Additionally, the effect of various type of MWCNT filler treatments using polyoxyethylene octyl phenyl ether (Triton X-100), sodium dodecyl sulfate (SDS) and 3-aminopropyltriethoxy silane (AMPTES) on the dielectric properties of epoxy thin film composites were investigated. The results showed that the increment of MWCNT loading increased the dielectric properties of the composite system. Meanwhile, chemically treated MWCNTs, especially MWCNT treated with SDS, showed good dielectric properties. Furthermore, morphological study showed an improvement in the dispersion of filler throughout the epoxy matrix in the treated composite system compared to the untreated system. TEM images also showed that treated MWCNT filler increased wall thickness of nanotube.

Since the 1940s, infrared (IR) detection and imaging at wavelengths in the two atmospheric windows of 3 to 5 and 8 to 14 μm has been extensively researched. Through several generations, these detectors have undergone considerable developments and have found use in various applications in different fields including military, space science, medicine and engineering. For the most recently proposed generation, these detectors are required to achieve high-speed detection with spectral and polarization selectivity while operating at room temperature. Antenna coupled IR detectors appear to be the most promising candidate to achieve these requirements and has received substantial attention from research in recent years. This paper sets out to present a review of the antenna coupled IR detector family, to explore the main concepts behind the detectors as well as outline their critical and challenging design considerations. In this context, the design of both elements, the antenna and the sensor, will be presented individually followed by the challenging techniques in the impedance matching between both elements. Some hands-on fabrication techniques will then be explored. Finally, a discussion on the coupled IR detector is presented with the aim of providing some useful insights into promising future work.

The ambient vibration-based micro electromechanical systems (MEMS) piezoelectric harvester has become an important subject in most research publications. Providing a green and virtually infinite alternative power source to traditional energy sources, this harvester will significantly expand the applications of wireless sensor networks and other technologies. Using piezoelectric materials to harvest the ambient vibrations that surround a system is one method that has seen a dramatic rise in the power-harvesting applications. The simplicity associated with piezoelectric micro-generators makes them very attractive for MEMS applications in which ambient vibrations are harvested and converted into electric energy. These micro generators can become an alternative to the battery-based solutions in the future, especially for remote systems. In this paper, we proposed a model and presented the simulation of a MEMS-based arrayed energy harvester under ambient vibration excitation using the Coventorware approach. This arrayed cantilever-based MEMS energy harvester that operates under ambient excitation of frequency band of 67 to 70 Hz, within a base acceleration of 0.2 to 1.3 g produces an output power of 6.8 μw and 0.4 volts at 20.1 k-ohms load.

This paper presents the development of a novel one-side-electrode-type fluidic-based capacitive pressure sensor. A pressure sensor using a one-side-electrode and an implementation of electrical double layer capacitance concept was proposed. Mechanical analysis of the membrane was carried out using the finite-element analysis in terms of deflection and Mises stress. A sensor with a circular membrane radius of 3.2 mm, membrane thickness of 0.8 mm, microchannel thickness of 0.5 mm, and microchannel width of 0.5 mm was fabricated using polydimethylsiloxane. The validation was made between the analytical and experimental results for fluid mechanisms inside the sensor. This showed that the displacement for all types of liquid, including methanol, ethanol, and silicon oil was linearly aligned. Methanol was chosen as an electrolyte due to its liquid properties, such as low surface tension and dielectric permittivity. From the experimental results, the operating frequency, response time, and sensitivity of the sensor were 1.2 kHz, 0.12 s, and 0.77 pF/kPa, respectively. The effects of vibration, temperature, and lifetime were also discussed in this paper.

A new high speed Complementary Metal Oxide Semiconductor (CMOS) pixel readout circuitry consuming a small area is proposed. The whole schematic is designed using Silterra 0.18 \(\mu \)m CMOS technology and consists of 12 small-sized MOSFETs that are one-third smaller than other solutions. The time taken to capture an image of the inner body is better than that in the literature, although the same input current is used. Simulation result shows that at the minimum input current of 3 nA, the image for the three pixels at the same row can be obtained clearly at every clock cycle.

This study is the first to demonstrate characteristics optimization of nanowire resistance load inverter. Noise margins and inflection voltage of transfer characteristics are used as limiting factors in this optimization. Results indicate that optimization depends on resistance value. Increasing of load resistor tends to increasing in noise margins until saturation point, increasing load resistor after this point will not improve noise margins significantly.

Antenna coupled Infrared (IR) detectors are increasingly researched for their promising fast response, uncooled operation and CMOS compatibility. However, their three order of magnitude lower detectivity compared to other commercial IR detectors is the main obstacle to be commercialized. One of the directions that is expected to increase the detectivity is through decreasing the expected sever losses as well as crosstalk that may arise due to surface waves. This direction is addressed in this work by integrating the detector with a spherical reflector which is presented here for the first time. The performance enhancement of the dipole antenna by spherical reflector backed structure is thus studied here through simulation using CST. The simulation shows a 20 dB increase in the gain of the spherical reflector backed structure compared to the simple dipole without the reflector.

The fluidic based multidirectional flow sensor inspired from artificial cupula was presented in this paper. It is consists of dome-shaped membrane, microchannel and one-side electrode with implementation of electrical double layer capacitor as a sensing element. The PDMS with ratio 20:1 was selected as a material because it is suitable to be implemented as a membrane. The micro-stamping technique for fabrication of dome-shaped membrane was proposed where the uniform thickness of membrane can be achieved. The operating frequency of the sensor using methanol was 1.5 kHz. The flow measurement was done by using water channel which flow rate 10 to 40 cm/s was applied with the resolution of 5 cm/s. The directionality tests for flow direction and angle also were carried out and it is proved that the sensor was able to detect the flow in omnidirectional directions.