Capacitive and ohmic RF NEMS switches based on vertical carbon nanotubes

2010 ◽  
Vol 2 (5) ◽  
pp. 433-440 ◽  
Author(s):  
A. Ziaei ◽  
M. Charles ◽  
M. Le Baillif ◽  
S. Xavier ◽  
A. Caillard ◽  
...  
Keyword(s):  
Ohmic Contact ◽  
High Frequency ◽  
Simulation Software ◽  
Operating Voltage ◽  
60 Ghz ◽  
Deposition Method ◽  
Rf Switch ◽  
High Isolation ◽  
Contact Switch ◽  
Walled Cnts

The objective is to demonstrate a reproducible carbon nanotube (CNT)-based technology for radio frequency (RF) switch working in the range of 40–60 GHz and fulfilling the specifications: low losses, high isolation, and an operating voltage below 30 V. The first processed component had an operating voltage of 14 V for an ohmic contact in a Nano-Electro Mechanical System (NEMS) tweezer design. This result is confirmed by theory with an operating voltage of 13 V. A capacitive-contact NEMS is also developed using multi-walled CNTs (MWCNTs) coated with a SiO2 dielectric layer deposited by electron beam induced deposition method (EBID). High Frequency Simulation Software (HFSS) RF-simulation on an innovative NEMS geometry shows encouraging results with transmission ratios between “on” state and “off” state up to 34% for ohmic-contact switch and 25% for a capacitive-contact switch.

scholarly journals A Compact Four-Port Coplanar Antenna Based on an Excitation Switching Reconfigurable Mechanism for Cognitive Radio Applications

2019 ◽  
Vol 9 (15) ◽  
pp. 3157 ◽  
Author(s):  
O ◽  
Jin ◽  
Choi
Keyword(s):  
Cognitive Radio ◽  
High Frequency ◽  
Coplanar Waveguide ◽  
Low Frequency ◽  
Loop Antenna ◽  
Ultra Wideband ◽  
Frequency Range ◽  
Uwb Antenna ◽  
High Isolation ◽  
Loop Antennas

In this paper, we propose a compact four-port coplanar antenna for cognitive radio applications. The proposed antenna consists of a coplanar waveguide (CPW)-fed ultra-wideband (UWB) antenna and three inner rectangular loop antennas. The dimensions of the proposed antenna are 42 mm × 50 mm × 0.8 mm. The UWB antenna is used for spectrum sensing and fully covers the UWB spectrum of 3.1–10.6 GHz. The three loop antennas cover the UWB frequency band partially for communication purposes. The first loop antenna for the low frequency range operates from 2.96 GHz to 5.38 GHz. The second loop antenna is in charge of the mid band from 5.31 GHz to 8.62 GHz. The third antenna operates from 8.48 GHz to 11.02 GHz, which is the high-frequency range. A high isolation level (greater than 17.3 dB) is realized among the UWB antenna and three loop antennas without applying any additional decoupling structures. The realized gains of the UWB antenna and three loop antennas are greater than 2.7 dBi and 1.38 dBi, respectively.

Compact Bandpass-Filtering Response Power Dividers with High Isolation and High Frequency Selectivity

2017 ◽  
Vol 37 (1) ◽  
pp. 73-79 ◽  
Author(s):  
Kaijun Song ◽  
Fan Zhang ◽  
Yu Zhu ◽  
Maoyu Fan ◽  
Yong Fan
Keyword(s):  
High Frequency ◽  
Frequency Selectivity ◽  
Power Dividers ◽  
High Isolation

scholarly journals Research and Fabrication of High-Frequency Broadband and Omnidirectional Transmitting Transducer

Sensors ◽  
2018 ◽  
Vol 18 (7) ◽  
pp. 2347 ◽  
Author(s):  
Shaohua Hao ◽  
Hongwei Wang ◽  
Chao Zhong ◽  
Likun Wang ◽  
Hao Zhang
Keyword(s):  
Composite Material ◽  
High Frequency ◽  
Wide Band ◽  
Simulation Software ◽  
Piezoelectric Composite ◽  
Voltage Response ◽  
Forming Process ◽  
Composite Ring ◽  
Matching Layer ◽  
Acoustic Transducer

A wide-band cylindrical transducer was developed by using the wide band of the composite material and the matched matching layer for multimode coupling. Firstly, the structure size of the transducer’s sensitive component was designed by using ANSYS simulation software. Secondly, the piezoelectric composite ring-shaped sensitive component was fabricated by the piezoelectric composite curved-surface forming process, and the matching layer was coated on the periphery of the ring-shaped piezoelectric composite material. Finally, it was encapsulated and the electrodes were drawn out to make a high-frequency broadband horizontal omnidirectional water acoustic transducer prototype. After testing, the working frequency range of the transducer was 230–380 kHz, and the maximum transmission voltage response was 168 dB in the water.

Compact bandpass-filtering response power divider with high-frequency selectivity and high isolation

2019 ◽  
Vol 11 (08) ◽  
pp. 755-760
Author(s):  
Jiawei Li ◽  
Kaijun Song ◽  
Fei Xia ◽  
Shema Richard Patience ◽  
Song Guo ◽  
...  
Keyword(s):  
Slow Wave ◽  
High Frequency ◽  
Reasonable Agreement ◽  
Frequency Selectivity ◽  
Power Divider ◽  
Dual Mode ◽  
High Isolation ◽  
Wave Characteristics ◽  
Capacitive Load

AbstractA compact high-isolation power divider with bandpass response and high-frequency selectivity is presented in this letter. Two dual-mode resonators are used to realize filtering response. The circuit size of the proposed power divider can be reduced by using dual-mode capacitance loaded square meander loop resonators. Due to capacitive load, the resonator can exhibit slow-wave characteristics, which can be utilized to suppress harmonics and reduce size. The simulated and measured results show reasonable agreement.

scholarly journals High Frequency Properties of Ni-Zn-Cu Ferrite Thick Films Prepared by Aerosol Deposition Method

2004 ◽  
Vol 51 (9) ◽  
pp. 691-697 ◽  
Author(s):  
Ryohei Kobayashi ◽  
Satoshi Sugimoto ◽  
Toshio Kagotani ◽  
Koichiro Inomata ◽  
Jun Akedo ◽  
...  
Keyword(s):  
High Frequency ◽  
Thick Films ◽  
Aerosol Deposition ◽  
Deposition Method ◽  
Aerosol Deposition Method ◽  
Frequency Properties

Analysis of the Impact of Plasma Sheath on GPS Antenna

2012 ◽  
Vol 229-231 ◽  
pp. 1614-1617
Author(s):  
Jiang Fan Liu ◽  
Guo Bin Wan ◽  
Jin Sheng Zhang ◽  
Xiao Li Xi
Keyword(s):  
Electron Density ◽  
High Frequency ◽  
Plasma Electron ◽  
Simulation Software ◽  
Plasma Sheath ◽  
Operating Frequency ◽  
Nonuniform Plasma ◽  
Peak Density ◽  
Gps Navigation ◽  
The Impact

The electromagnetic simulation software CST was used to analyze the effects of reentry plasma sheath on the GPS navigation antenna. The Impedance and radiation characteristics of antenna were studied on condition that the antenna was coated with uniform and nonuniform electron density distribution plasma sheath respectively. The results show that, the antenna coated with the uniform plasma sheath, the plasma electron density increasing, the antenna operating frequency moves to high-frequency and that the directivity decreases as well; when the antenna was coated with nonuniform plasma, with the higher electron peak density of plasma sheath, besides that the operating frequency also moves to high-frequency, the bandwidth stretches wide and the return loss reduces; the antenna radiation pattern distorts seriously at the electron peak density of 1018m-3.

A Design of Printed Inverted-F Antenna for RFID Tag at 5.8 GHz

2013 ◽  
Vol 427-429 ◽  
pp. 1293-1296
Author(s):  
Yan Zhong Yu ◽  
Ji Zhen Ni ◽  
Xian Hui Li
Keyword(s):  
High Frequency ◽  
Printed Circuit Board ◽  
Ground Plane ◽  
Simulation Software ◽  
Circuit Board ◽  
Electromagnetic Simulation ◽  
Antenna Structure ◽  
Rfid Tag ◽  
Printed Circuit ◽  
Substrate Layer

A printed inverted-F antenna for RFID tag at 5.8 GHz is designed in this paper. The antenna structure consists of an inverted-F patch, a substrate layer, and a ground plane. To reduce costs, the FR4 is selected as the material of substrate layer, which is used commonly in PCB (Printed Circuit Board). Its relative permittivity is 4.4 and a loss tangent is 0.02. The inverted-F patch and ground plane are laid on/under the substrate layer respectively. The designed antenna is modeled, simulated and optimized by using HFSS (high frequency electromagnetic simulation software). Simulation results demonstrate that the printed inverted-F antenna can satisfy the requirements of RFID Tag applications.

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