scholarly journals Design of a RF Switch Used in Redundant Atomic Clock Configurations

Sensors ◽  
2019 ◽  
Vol 19 (10) ◽  
pp. 2331
Author(s):  
Hou ◽  
Wang ◽  
Tang ◽  
Zhang
Keyword(s):  
Return Loss ◽  
Performance Metrics ◽  
Atomic Clock ◽  
Experimental Result ◽  
Atomic Clocks ◽  
Rf Switch ◽  
Switching Speed ◽  
Rf Switches ◽  
Fast Switching ◽  
System A

Atomic clocks provide frequency reference signals for communication, aerospace, satellite navigation and other systems. The redundant configuration of atomic clocks is necessary for ensuring the continuity and stability of the system. A radio frequency (RF) switch is usually used as a switching device in the switching system of the host atomic clock and the backup atomic clock. When the atomic clock fails, the switching between the host and the backup clock can be carried out quickly. Aiming at the fast switching requirements of atomic clock RF signals, this paper proposes a new series-shunt Positive Intrinsic Negative (PIN) switch design. In this paper, the evaluation of the RF switches is conducted by using the metrics of switching speed, insertion loss, isolation, return loss at on state and return loss at off state. Experimental result shows that the new PIN switch has better and more comprehensive performance metrics than the electromechanical switch, FET switch and conventional PIN switch. In particular, the switching speed is 53 ns faster than the conventional series-shunt PIN switch.

scholarly journals Performance analysis of Ultra-wideband RF switch using discrete PIN diode in SC-79 package for medical application of microwave imaging

2019 ◽  
Vol 9 (6) ◽  
pp. 4668
Author(s):  
Noor Azwan Shairi ◽  
Nursyahirah Mohd Sanusi ◽  
Adib Othman ◽  
Zahriladha Zakaria ◽  
Imran Mohd Ibrahim
Keyword(s):  
Performance Analysis ◽  
Return Loss ◽  
Imaging System ◽  
Medical Application ◽  
Microwave Imaging ◽  
Ultra Wideband ◽  
Pin Diode ◽  
Rf Switch ◽  
Rf Switches ◽  
Magnetic Resonance Imaging Mri

<span>Microwave imaging is an emerging technology in the medical application which have similar functions as X-ray, Magnetic Resonance Imaging (MRI), and Computed Tomography scan (CT scan). In designing a microwave imaging system for medical application, it can use a monostatic radar approach by transmitting a Gaussian pulse (with an ultra-wideband (UWB) frequency). In this system, eight antennas are required with the support of RF switches. Thus, it is important to get the best performance of UWB RF switch in this application. Therefore, this paper presents the performance analysis of four different RF switch topologies (Design 1, 2, 3 and 4) using discrete PIN diode in SC-79 package. The design was based on single pole double throw (SPDT) switch. As result, Design 2 is the best topology after considering the tradeoff between isolation and return loss performances. Based on the three cascaded SPDT switches of Design 2, the insertion loss was less than -2 dB and return loss was more than -10 dB. Meanwhile, the isolation bandwidth (at the minimum isolation of -20 dB) was from 0.5 to 3.7 GHz (with 3.2 GHz bandwidth), hence, it could be used in the UWB frequency for medical application of microwave imaging.</span>

High-Density Memristor-CMOS Ternary Logic Family

2020 ◽  
Author(s):  
Xiaoyuan Wang ◽  
Pengfei Zhou ◽  
Jason Eshraghian ◽  
Chih-Yang Lin ◽  
Herbert Ho-Ching Iu ◽  
...  
Keyword(s):  
Indium Tin Oxide ◽  
Practical Implementation ◽  
Switching Speed ◽  
High Data ◽  
Fast Switching ◽  
Data Density ◽  
Order Of Magnitude ◽  
High Transconductance ◽  
Logic Functions ◽  
Magnitude Improvement

<div>This paper presents the first experimental demonstration</div><div>of a ternary memristor-CMOS logic family. We systematically</div><div>design, simulate and experimentally verify the primitive</div><div>logic functions: the ternary AND, OR and NOT gates. These are then used to build combinational ternary NAND, NOR, XOR and XNOR gates, as well as data handling ternary MAX and MIN gates. Our simulations are performed using a 50-nm process which are verified with in-house fabricated indium-tin-oxide memristors, optimized for fast switching, high transconductance, and low current leakage. We obtain close to an order of magnitude improvement in data density over conventional CMOS logic, and a reduction of switching speed by a factor of 13 over prior state-of-the-art ternary memristor results. We anticipate extensions of this work can realize practical implementation where high data density is of critical importance.</div>

Synthesis and Characterization of Polyaniline Film

2011 ◽  
Vol 239-242 ◽  
pp. 1382-1385
Author(s):  
Na Xu ◽  
Xiao Dong Shen ◽  
Sheng Cui
Keyword(s):  
Ammonium Persulfate ◽  
Pani Film ◽  
Cyclic Voltammograms ◽  
Ultrasonic Dispersion ◽  
Switching Speed ◽  
Color Changes ◽  
Fast Switching ◽  
Ft Ir ◽  
The Relationship

The electrochromic PANI film was prepared by emulsion polymerization with dodecyl benzene sulphonic acid (DBSA) as dopant and ammonium persulfate (APS) as initiator. Ultrasonic dispersion was adopted in the polymerization. The electrochemical properties, the surface morphology and structure of the prepared PANI film was characterized by means of Fourier Transform infrared spectroscopy (FT-IR), cyclic voltammograms (CV) and field emission scanning electron microscope (FE-SEM), respectively. The relationship between the morphology and properties of PANI film was detailedly discussed. The PANI film exhibited an excellent electrochromism with reversible color changes form yellow to purple. The PANI film also had quite good reaction kinetics with fast switching speed, and the response time for oxidation and reduction were 65 ms and 66 ms, respectively.

Improved electrochromic performance of a radio frequency magnetron sputtered NiO thin film with high optical switching speed

RSC Advances ◽  
2016 ◽  
Vol 6 (83) ◽  
pp. 79668-79680 ◽  
Author(s):  
K. S. Usha ◽  
R. Sivakumar ◽  
C. Sanjeeviraja ◽  
Vasant Sathe ◽  
V. Ganesan ◽  
...  
Keyword(s):  
Thin Film ◽  
Radio Frequency ◽  
Optical Switching ◽  
Switching Time ◽  
Rf Magnetron Sputtering ◽  
Optical Modulation ◽  
Switching Speed ◽  
Coloration Efficiency ◽  
Fast Switching ◽  
Nio Thin Film

A nickel oxide (NiO) thin film with better reversibility, high optical modulation, and enhanced coloration efficiency with fast switching time was prepared using radio frequency (rf) magnetron sputtering technique.

Performance analysis of all optical 2 × 1 multiplexer in 2D photonic crystal structure

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Asghar Askarian
Keyword(s):  
Photonic Crystal ◽  
Optical Waveguides ◽  
Hexagonal Lattice ◽  
Optical Processing ◽  
Switching Speed ◽  
Fast Switching ◽  
Nonlinear Photonic Crystal ◽  
All Optical ◽  
Difference Time ◽  
Optical Structure

Abstract In optical processing systems, multiplexer is used to design optical devices such as arithmetic logic unit (ALU) and shift register (SR). Through this paper, we investigate the application of nonlinear photonic crystal ring resonator (PhCRR) based on nonlinear Kerr effect for realizing an all optical 2 × 1 multiplexer. The structure consists of two PhCRRs and five optical waveguides using hexagonal lattice silicon (Si) rods with a background of air. Performance of all optical 2 × 1 multiplexer is replicated with the help of finite difference time domain (FDTD) procedure at a wavelength of 1571 nm, and simulations presented an ultra-compact optical structure with ultra-fast switching speed.

Low-Density Fan-Out Heterogeneous Integration of MEMS Tunable Capacitor and RF SOI Switch

2019 ◽  
Vol 2019 (1) ◽  
pp. 000051-000055
Author(s):  
Rameen Hadizadeh ◽  
Anssi Laitinen ◽  
Niko Kuusniemi ◽  
Volker Blaschke ◽  
David Molinero ◽  
...  
Keyword(s):  
High Voltage ◽  
Microelectromechanical Systems ◽  
Performance Metrics ◽  
Circuit Board ◽  
Low Density ◽  
Rf Switch ◽  
Tunable Capacitor ◽  
Esd Protection ◽  
Mems Device ◽  
The Impact

Abstract Using Low-Density Fan-Out (LDFO) packaging technology, a radio frequency (RF) microelectromechanical systems (MEMS) tunable capacitor array composed of electrostatically actuated beams on 180nm high-voltage CMOS silicon was heterogeneously integrated with a single-pole four-terminal (SP4T) RF switch on 180nm CMOS silicon-on-insulator (SOI). The primary objective of this study was to determine the manufacturability of this System-in-Package (SiP) design, which is proven at time zero through survival of the MEMS device based on acceptable MEMS performance metrics. In addition, the RF SOI switch provides high-voltage electrostatic discharge (ESD) protection for the MEMS device. Capacitive MEMS structures are particularly sensitive to unpredictable electrostatic charging scenarios, such as handling after package assembly and printed circuit board (PCB) surface mount processing. Consequently, resistance to dielectric breakdown by means of robust ESD protection is a very desirable quality. Integrating the RF switch in close proximity with the MEMS device not only enables the ability to withstand charging scenarios in excess of 1kV (human body model), it mitigates the impact of parasitics on RF performance by minimizing interconnect lengths and complexity.

scholarly journals Modeling and Experimental Investigation of Electromagnetic Interference (EMI) for SiC-Based Motor Drive

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5173
Author(s):  
Yingzhe Wu ◽  
Shan Yin ◽  
Hui Li ◽  
Minghai Dong
Keyword(s):  
Electromagnetic Interference ◽  
Semiconductor Device ◽  
Frequency Domain Analysis ◽  
Motor Drives ◽  
Motor Drive ◽  
Switching Frequency ◽  
Switching Speed ◽  
Fast Switching ◽  
Source Voltage ◽  
Switching Characteristics

The motor drive has been widely adopted in modern power applications. With the emergency of the next generation wide bandgap semiconductor device, such as silicon carbide (SiC) MOSFET, performance of the motor drive can be improved in terms of efficiency, power density, and reliability. However, the fast switching transient and serious switching ringing of the SiC MOSFET can cause unwanted high-frequency (HF) electromagnetic interference (EMI), which may significantly reduce the reliability of the motor drive in many aspects. In order to comprehensively reveal the mechanism of the EMI previously used in motor drives using SiC MOSFET, this paper plans to analyze the influences of both HF impedance of the motor and switching characteristics of the SiC MOSFET. A simulation model for motor drives has been proposed, which contains the HF circuit model of the motor as well as a semi-behavioral analytical model of the SiC MOSFET. Since the model shows a good agreement with the experimentally measured results on spectra of drain-source voltage of the SiC MOSFET (vds), phase to ground voltage of the motor (vphase), CM voltage (vcm), phase current of the motor (idm), and CM current (icm), it can be adopted to quantitatively investigate the influence of the motor impedance on EMI through frequency-domain analysis. Additionally, the impacts of switching characteristics of SiC MOSFET on EMI are also well studied according to relative experiment results in terms of switching speed, switching frequency, and switching ringing. Based on the analysis above, the relationship between motor impedance, switching characteristics of the SiC MOSFET, and HF EMI can be figured out, which is able to provide much helpful assistance for application of the motor drive.

scholarly journals Coordinate time in the vicinity of the Earth

1986 ◽  
Vol 114 ◽  
pp. 299-313 ◽  
Author(s):  
D. W. Allan ◽  
N. Ashby
Keyword(s):  
General Relativity ◽  
Atomic Clock ◽  
Space Vehicles ◽  
Atomic Clocks ◽  
Coordinate Time ◽  
The Earth ◽  
Frequency Comparison ◽  
New Applications ◽  
Frequency Metrology

Atomic clock accuracies continue to improve rapidly, requiring the inclusion of general relativity for unambiguous time and frequency clock comparisons. Atomic clocks are now placed on space vehicles and there are many new applications of time and frequency metrology. This paper addresses theoretical and practical limitations in the accuracy of atomic clock comparisons arising from relativity, and demonstrates that accuracies of time and frequency comparison can approach a few picoseconds and a few parts in 1016, respectively.

Analysis and Design of a Robust RF MEMS Switch

2012 ◽  
Author(s):  
Ibrahim Chamseddine ◽  
Hadi Kasab ◽  
Maya Antoun ◽  
Tawfiq Dahdah ◽  
Mohammed Mirhi ◽  
...  
Keyword(s):  
Failure Modes ◽  
Rf Mems ◽  
Dielectric Breakdown ◽  
Rf Switch ◽  
Switching Speed ◽  
Analysis And Design ◽  
Electrostatically Actuated ◽  
Mems Switch ◽  
Switching Performance ◽  
Contact Adhesion

A MEMS RF switch is expected to undergo 10 billion switching cycles before failure. Until complete physical explanation for these failure modes that include contact adhesion, damping effects, stiction, increases in resistance with time, dielectric breakdown, and electron trapping is fully established, the technology’s numerous advantages cannot be harvested reliably and efficiently. This paper investigates prospective solutions to problems in switch designs by proposing a new design for the switch. We consider the new design from different perspectives: dynamic, electric, fluidic, etc. It is billed to overcome the difficulties and involves the implementation of liquid metal contact electrostatically actuated to ensure the same switching performance, with prolonged life span, and robust switching speed.

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