scholarly journals A MEMS Ultra-Wideband (UWB) Power Sensor with a Fe-Co-B Core Planar Inductor and a Vibrating Diaphragm Capacitor

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3858
Author(s):  
Sujitha Vejella ◽  
Sazzadur Chowdhury
Keyword(s):  
Microelectromechanical Systems ◽  
Ultra Wideband ◽  
Induced Voltage ◽  
Adhesively Bonded ◽  
Capacitance Change ◽  
Frequency Independent ◽  
Power Sensor ◽  
Footprint Area ◽  
Microfabrication Techniques ◽  
2D Array

The design of a microelectromechanical systems (MEMS) ultra-wideband (UWB) RMS power sensor is presented. The sensor incorporates a microfabricated Fe-Co-B core planar inductor and a microfabricated vibrating diaphragm variable capacitor on adhesively bonded glass wafers in a footprint area of 970 × 970 µm2 to operate in the 3.1–10.6 GHz UWB frequency range. When exposed to a far-field UWB electromagnetic radiation, the planar inductor acts as a loop antenna to generate a frequency-independent voltage across the MEMS capacitor. The voltage generates a coulombic attraction force between the diaphragm and backplate that deforms the diaphragm to change the capacitance. The frequency-independent capacitance change is sensed using a transimpedance amplifier to generate an output voltage. The sensor exhibits a linear capacitance change induced voltage relation and a calculated sensitivity of 4.5 aF/0.8 µA/m. The sensor can be used as a standalone UWB power sensor or as a 2D array for microwave-based biomedical diagnostic imaging applications or for non-contact material characterization. The device can easily be tailored for power sensing in other application areas such as, 5G, WiFi, and Internet-of-Things (IoT). The foreseen fabrication technique can rely on standard readily available microfabrication techniques.

Response characteristics of coincident loop transient electromagnetic systems

Geophysics ◽  
1982 ◽  
Vol 47 (9) ◽  
pp. 1325-1330 ◽  
Author(s):  
P. Weidelt
Keyword(s):  
Step Function ◽  
Voltage Response ◽  
Complex Frequency ◽  
Induced Voltage ◽  
Response Characteristics ◽  
Transient Electromagnetic ◽  
Driving Current ◽  
Occasional Occurrence ◽  
Frequency Independent ◽  
Independent Distribution

The occasional occurrence of persistent sign reversals in coincident loop transient electromagnetic (TEM) measurements stimulates an investigation of possible causes for this effect. By examining the response in the complex frequency plane near the spectrum of freely decaying current modes, it is shown that for any physically reasonable frequency‐independent distribution of electrical conductivity and magnetic permeability the voltage response to a step function driving current is of one sign only. Moreover, under the conditions mentioned above, the logarithm of the induced voltage is a decreasing convex function of time. These characteristics are retained for more general time functions of the driving current. The conservation of sign for frequency‐independent material parameters supports the assumption of IP effects as a possible mechanism for sign reversals. The latter point is illustrated by a simplified example.

Humidity-Induced Voltage Shift on MEMS Pressure Sensors

2003 ◽  
Vol 125 (4) ◽  
pp. 470-474 ◽  
Author(s):  
J. Albert Chiou ◽  
Steven Chen ◽  
Jinbao Jiao
Keyword(s):  
Pressure Sensor ◽  
Microelectromechanical Systems ◽  
Pressure Sensors ◽  
Anodic Bonding ◽  
Absolute Pressure ◽  
Stress Effect ◽  
Induced Voltage ◽  
Voltage Shift ◽  
Mems Pressure Sensors ◽  
Vacuum Cavity

The pressure sensor is one of the major applications of microelectromechanical systems (MEMS). An absolute pressure sensor utilizes anodic bonding to create a vacuum cavity between the silicon diaphragm and glass substrate. The manifold absolute pressure (MAP) sensing elements from a new supplier have exhibited negative voltage shifts after exposure to humidity. A hypothesis has been established that poor anodic bonding causes an angstrom-level gap between the silicon substrate and glass. Once moisture enters the gap in a vapor form and condenses as water droplets, surface tension can induce a piezoresistive stress effect that causes an unacceptable voltage shift. Finite element analyses were performed to simulate the phenomenon and the results correlated well with experimental observations.

scholarly journals Design, Simulation and Fabrication of A Novel MEMS Based Pulsometer

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 951 ◽  
Author(s):  
Xingzhe Zhang ◽  
Arnesh Bose ◽  
Dinesh Maddipatla ◽  
Binu Narakathu ◽  
Vikram Turkani ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Biomedical Applications ◽  
Microelectromechanical Systems ◽  
Comsol Multiphysics ◽  
Capacitance Change ◽  
Axis Direction ◽  
Simulation Results

A novel pulsometer was successfully developed using microelectromechanical systems (MEMS) based silicon-on-glass (SOG) technology for biomedical applications. The sensor was modelled and simulated in COMSOL Multiphysics® for pressures ranging from 0 to 40 mmHg. The capability of the fabricated pulsometer to detect movements in x and z-axis directions was investigated. The simulation results demonstrated displacement changes as high as of 98% and 36% in the x and z-axis directions, respectively for 40 mmHg, which correspond to typical radial blood pressure (rBP) on the wrist. In addition, an average capacitance change of 1 nF was experimentally obtained in the x-axis direction, from −5 V to 5 V. The response of the pulsometer is analyzed and presented in this paper.

scholarly journals Gold-implanted plasmonic quartz plate as a launch pad for laser-driven photoacoustic microfluidic pumps

2019 ◽  
Vol 116 (14) ◽  
pp. 6580-6585 ◽  
Author(s):  
Shuai Yue ◽  
Feng Lin ◽  
Qiuhui Zhang ◽  
Njumbe Epie ◽  
Suchuan Dong ◽  
...  
Keyword(s):  
High Speed ◽  
Microelectromechanical Systems ◽  
Acoustic Streaming ◽  
Fluid Motion ◽  
Quartz Plate ◽  
Ultrasound Wave ◽  
High Speed Imaging ◽  
Driving Mechanisms ◽  
Easy Integration ◽  
Microfabrication Techniques

Enabled initially by the development of microelectromechanical systems, current microfluidic pumps still require advanced microfabrication techniques to create a variety of fluid-driving mechanisms. Here we report a generation of micropumps that involve no moving parts and microstructures. This micropump is based on a principle of photoacoustic laser streaming and is simply made of an Au-implanted plasmonic quartz plate. Under a pulsed laser excitation, any point on the plate can generate a directional long-lasting ultrasound wave which drives the fluid via acoustic streaming. Manipulating and programming laser beams can easily create a single pump, a moving pump, and multiple pumps. The underlying pumping mechanism of photoacoustic streaming is verified by high-speed imaging of the fluid motion after a single laser pulse. As many light-absorbing materials have been identified for efficient photoacoustic generation, photoacoustic micropumps can have diversity in their implementation. These laser-driven fabrication-free micropumps open up a generation of pumping technology and opportunities for easy integration and versatile microfluidic applications.

scholarly journals Vivaldi Antenna Arrays Feed by Frequency-Independent Phase Shifter for High Directivity and Gain Used in Microwave Sensing and Communication Applications

Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6091
Author(s):  
Jiwan Ghimire ◽  
Feyisa Debo Diba ◽  
Ji-Hoon Kim ◽  
Dong-You Choi
Keyword(s):  
Antenna Arrays ◽  
Phase Shifter ◽  
Antenna System ◽  
Phase Shifters ◽  
Ultra Wideband ◽  
Feed System ◽  
Power Splitter ◽  
Frequency Independent ◽  
Vivaldi Antenna ◽  
The Right

This paper describes a novel feed system for compact, wideband, high gain six-slot Vivaldi antenna arrays on a single substrate layer using a unique combination of power splitters based on binary T-junction power splitter topology, frequency-independent phase shifter, and a T-branch. The proposed antenna system consists of six Vivaldi antennas, three on the left, and three on the right arm. Each arm connects with T-junction power divider splitter topology, given that the right arm is linked through a frequency-independent phase shifter. Phase shifters ensure that the beam is symmetrical without splitting in a radiating plane so that highly directive radiation patterns occur. The optimal return losses (S-parameters) are well enriched by reforming Vivaldi’s feeding arms and optimizing Vivaldi slots and feeds. A novel feature of our design is that the antenna exhibits the arrangements of a T-junction power splitter with an out-of-phase feeding mechanism in one of the arms, followed by a T-branching feeding to even arrays of proper Vivaldi antenna arrangement contributing high realized gain and front-to-back ratio up to 14.12 dBi and 23.23 dB respectively applicable for not only ultra-wideband (UWB) application, also for sensing and position detecting. The high directivity over the entire UWB frequency band in both higher and lower frequency ranges ensures that the antenna can be used in microwave through-wall imaging along with resolution imaging for ground penetration radar (GPR) applications. The fabricated antenna parameters are in close agreement with the simulated and measured results and are deployed for the detection of targets inside the voids of the concrete brick.

scholarly journals Recent Developments of Reconfigurable Antennas for Current and Future Wireless Communication Systems

Electronics ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 128 ◽  
Author(s):  
Naser Ojaroudi Parchin ◽  
Haleh Jahanbakhsh Basherlou ◽  
Yasir Al-Yasir ◽  
Raed Abd-Alhameed ◽  
Ahmed Abdulkhaleq ◽  
...  
Keyword(s):  
Communication Systems ◽  
Adaptive Systems ◽  
Microelectromechanical Systems ◽  
Multiple Input Multiple Output ◽  
Reconfigurable Antennas ◽  
Ultra Wideband ◽  
Fourth Generation ◽  
Mobile Terminals ◽  
Antenna Structure ◽  
Active Elements

Reconfigurable antennas play important roles in smart and adaptive systems and are the subject of many research studies. They offer several advantages such as multifunctional capabilities, minimized volume requirements, low front-end processing efforts with no need for a filtering element, good isolation, and sufficient out-of-band rejection; these make them well suited for use in wireless applications such as fourth generation (4G) and fifth generation (5G) mobile terminals. With the use of active materials such as microelectromechanical systems (MEMS), varactor or p-i-n (PIN) diodes, an antenna’s characteristics can be changed through altering the current flow on the antenna structure. If an antenna is to be reconfigurable into many different states, it needs to have an adequate number of active elements. However, a large number of high-quality active elements increases cost, and necessitates complex biasing networks and control circuitry. We review some recently proposed reconfigurable antenna designs suitable for use in wireless communications such as cognitive-ratio (CR), multiple-input multiple-output (MIMO), ultra-wideband (UWB), and 4G/5G mobile terminals. Several examples of antennas with different reconfigurability functions are analyzed and their performances are compared. Characteristics and fundamental properties of reconfigurable antennas with single and multiple reconfigurability modes are investigated.

scholarly journals MEMS Non-Absorbing Electromagnetic Power Sensor Employing the Effect of Radiation Pressure

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 767
Author(s):  
Ivan Ryger ◽  
Alexandra Artusio-Glimpse ◽  
Paul Williams ◽  
Gordon Shaw ◽  
Matthew Simons ◽  
...  
Keyword(s):  
Power Measurement ◽  
Mirror Reflection ◽  
Electromagnetic Power ◽  
Reflective Mirror ◽  
Frequency Independent ◽  
Power Sensor ◽  
Lock In ◽  
Measurement Approach ◽  
Mechanical Arrangement ◽  
Mirror Reflection Coefficient

We demonstrate a compact electromagnetic power sensor based on force effects of electromagnetic radiation onto a highly reflective mirror surface. Unlike the conventional power measurement approach, the photons are not absorbed and can be further used in the investigated system. In addition, the exerted force is frequency-independent, yielding a wide measurement frequency span being practically limited by the wavelength-dependent mirror reflection coefficient. The mechanical arrangement of two sensing elements in tandem suppresses the influence of gravity and vibrations on the power reading. We achieve a noise floor of about 1 W/√Hz and speed of 100 ms, being practically limited by sensor’s dynamics and lock-in amplifier filter settling time.

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