scholarly journals Parametric Analysis of the Edge Capacitance of Uniform Slots and Application to Frequency-Variation Permittivity Sensors

2021 ◽  
Vol 11 (15) ◽  
pp. 7000
Author(s):  
Jonathan Muñoz-Enano ◽  
Jesús Martel ◽  
Paris Vélez ◽  
Francisco Medina ◽  
Lijuan Su ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Resonance Frequency ◽  
Parametric Analysis ◽  
Frequency Variation ◽  
Substrate Thickness ◽  
Ground Structure ◽  
Simple Analytical Expression ◽  
Magnetic Wall ◽  
Different Dimensions ◽  
Defect Ground Structure

This paper presents a parametric analysis relative to the effects of the dielectric constant of the substrate, substrate thickness and slot width on the edge capacitance of a slot-based resonator. The interest is to find the conditions (ranges of the previously cited parameters) compatible with the presence of a quasi-magnetic wall in the plane of the slot (or plane of the metallization). If such magnetic wall is present (or roughly present), the electric field in the plane of the slot is tangential (or quasi-tangential) to it and the edge capacitance can be considered to be the parallel combination of the capacitances at both sides of the slot. Moreover, variations in one of such capacitances, e.g., caused by a change in the material on top of the slot, or by a modification of the dielectric constant of the substrate do not affect the opposite capacitance. Under the magnetic wall approximation, the capacitance of certain electrically small slot-based resonators can be easily linked to the dielectric constant of the material present on top of it. The consequence is that such resonators can be used as sensing elements in a permittivity sensor and the dielectric constant of the so-called material under test (MUT) can be determined from the measured resonance frequency and a simple analytical expression. In this paper, the results of this parametric analysis are validated by considering several sensing structures based on dumbbell defect ground structure (DB-DGS) resonators of different dimensions.

scholarly journals Discussion and Analysis of Dumbbell Defect-Ground-Structure (DB-DGS) Resonators for Sensing Applications from a Circuit Theory Perspective

Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8334
Author(s):  
Lijuan Su ◽  
Paris Vélez ◽  
Jonathan Muñoz-Enano ◽  
Ferran Martín
Keyword(s):  
Dielectric Constant ◽  
Transmission Lines ◽  
Physical Meaning ◽  
Parameter Extraction ◽  
Circuit Theory ◽  
Realistic Model ◽  
General Assumption ◽  
Ground Structure ◽  
Sensing Applications ◽  
Defect Ground Structure

Microstrip transmission lines loaded with dumbbell defect-ground-structure (DB-DGS) resonators transversally oriented have been exhaustively used in microwave circuits and sensors. Typically, these structures have been modelled by means of a parallel LC resonant tank series connected to the host line. However, the inductance and capacitance of such model do not have a physical meaning, since this model is inferred by transformation of a more realistic model, where the DB-DGS resonator, described by means of a resonant tank with inductance and capacitance related to the geometry of the DB-DGS, is magnetically coupled to the host line. From parameter extraction, the circuit parameters of both models are obtained by considering the DB-DGS covered with semi-infinite materials with different dielectric constant. The extracted parameters are coherent and reveal that the general assumption of considering the simple LC resonant tank series-connected to the line to describe the DB-DGS-loaded line is reasonable with some caution. The implications on the sensitivity, when the structure is devoted to operating as a permittivity sensor, are discussed.

scholarly journals Design of PCB Impedance Matching Inductors and Antennas for Single-Chip Communication Systems

2008 ◽  
Vol 2008 ◽  
pp. 1-7 ◽  
Author(s):  
J. Chung ◽  
S. Hamedi-Hagh
Keyword(s):  
Dielectric Constant ◽  
Resonance Frequency ◽  
Communication Systems ◽  
Return Loss ◽  
Impedance Matching ◽  
Portable Device ◽  
Single Chip ◽  
Matching Network

This paper presents the design of an inductor and an antenna for a portable device with GPS and FM capabilities. The inductor is designed to operate at the lower frequency FM band as part of a matching network and the antenna is designed to operate at the higher frequency GPS L1 band. The FR4 PCB used has a thickness of 1.6 mm with a dielectric constant of 3.8 and has two metallization layers. The inductor is designed with 1.5 mm trace width, 3.5 turns, and has a dimension of 14.5 mm × 14.5 mm. It has an inductance of 95 nH, a resistance of 2.9 Ω, a self-resonance frequency of 500 MHz, and a maximum Q of 51 from 100 MHz to 200 MHz (FM band). The antenna has a dimension of 49 mm × 36 mm and is designed to operate at 1.5754 GHz L1 band. It also has a return loss of −36 dB and a measured bandwidth of 250 MHz.

scholarly journals Circle Microstrip Antenna Simulation for Frequency 3.5 GHz

2021 ◽  
Vol 1 (1) ◽  
pp. 1-4
Author(s):  
Wildan Wildan ◽  
Dwi Astuti Cahyasiwi ◽  
Syah Alam ◽  
Mohd Azman Zakariya ◽  
Harry Ramza
Keyword(s):  
Dielectric Constant ◽  
Patch Antenna ◽  
Microstrip Antenna ◽  
Microstrip Line ◽  
Return Loss ◽  
Tangent Loss ◽  
Substrate Thickness ◽  
Total Radiation ◽  
Circular Patch Antenna ◽  
Working Frequency

This research proposed microstrip circular patch antenna simulation at a working frequency 3500 MHz. The antenna has been designed using a Duroid RT5880 substrate with dielectric constant (εr) = 2.2, substrate thickness (h) = 1.575 mm, and tangent loss = 0.0009 with microstrip line feeding. The simulation result, return loss value obtained -26.385, VSWR value 1.09, gain value 7.64 dBi, total radiation efficiency value -0.6489 dB, and bandwidth value 72 MHz (3468.8 MHz – 3541.9 MHz).

A multilayer dual wideband circularly polarized microstrip antenna with DGS for WLAN/Bluetooth/ZigBee/Wi-Max/ IMT band applications

2015 ◽  
Vol 9 (2) ◽  
pp. 317-325 ◽  
Author(s):  
Amanpreet Kaur ◽  
Rajesh Khanna ◽  
Machavaram Kartikeyan
Keyword(s):  
Dielectric Constant ◽  
Surface Area ◽  
Microstrip Antenna ◽  
Dual Band ◽  
Defected Ground Structure ◽  
Mobile Telecommunications ◽  
Ieee 802.11B ◽  
Ground Structure ◽  
Circularly Polarized ◽  
Feed Network

In this paper, a three layered stacked circularly polarized rectangular dual band microstrip antenna with a defected ground structure (DGS) and a feed network with stub (showing dual wideband characteristic) is designed, fabricated, and tested for WLAN, Zig bee, Wi-Max, and IMT band applications. The proposed antenna is fabricated on an FR4 substrate with dielectric constant (εr) of 4.4; tanδ of 0.0024 and a height of 1.57 mm.The antenna has a surface area of 4.8 × 4.1 cm2and a total height of 5.1 mm. The designed antenna covers two wireless bands from 2.39 to 2.64GHz and 3.39–3.76 GHZ with impedance bandwidths (VSWR < 2) of 250 MHz (9% bandwidth centered at 2.515 GHz) and 370 MHz (10% bandwidth centered at 3.57 GHz), respectively. This antenna is capable of covering IEEE 802.11b/g/n standards of WLAN from 2.4 to 2.485 GHz, bluetooth applications from 2.4 to 2.483 GHz, ZigBee applications from 2.4 to 2.485 GHz, IEEE 802.16/ Wi-MaX applications from 3.4 to 3.69 GHz and international mobile telecommunications (IMT) band from 3.4 to 3.6 GHz. As the antenna is circularly polarized, the misalignment of the receiver with transmitter does not affect the performance of the system. The antenna designing was done using CST MWS V'10 and the prototype of the designed antenna was tested for the validation of S11(dB) and gain results against the simulated ones experimentally. The proposed antenna shows a gain of 4.08 dBi at 2.5 GHz and a gain of 5.024 dBi at 3.51 GHz.

Effects of Nd2O3 on the microwave dielectric properties of BiNbO4 ceramics

1998 ◽  
Vol 13 (10) ◽  
pp. 2945-2949 ◽  
Author(s):  
Whan Choi ◽  
Kyung-Yong Kim ◽  
Myung-Rip Moon ◽  
Kyoo-Sik Bae
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Resonance Frequency ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Positive Direction ◽  
Microwave Dielectric ◽  
Triclinic Phase ◽  
Nd Substitution ◽  
Peak Value

Effects of Nd substitution with Bi on the microwave dielectric properties of BiNbO4 were studied. Bi1−xNdxNbO4 ceramics sintered at 920–980 °C consisted of orthorhombic and triclinic phases. The amount of triclinic phase increased with the increase in the Nd content, x, and sintering temperature. The apparent density and the dielectric constant decreased with the Nd content, but increased with sintering temperature, reached the peak values at 960 °C and then rapidly decreased. The Q × f0 value was between 11,000 and 13,000 GHz over all sintering temperatures for x < 0.05, but for x ≥ 0.05 it reached the peak value at 950 °C and then rapidly decreased. The temperature coefficient of resonance frequency increased in the positive direction with the Nd content and showed the minimum value of −1.82 ppm/°C for x = 0.025 sintered at 940 °C. However, it rapidly increased in the negative direction for sintering temperature over 960 °C.

Bendable Hexagonal Resonator Designs for Chipless Tag

2016 ◽  
Vol 850 ◽  
pp. 82-87
Author(s):  
Maisarah Abu ◽  
Nur Asyrani Mohd Asari ◽  
Khairul Nabilah Zainul Ariffin ◽  
Nurul Najwa Md Yusof ◽  
Eryana Eiyda Hussin
Keyword(s):  
Dielectric Constant ◽  
Cross Section ◽  
Substrate Thickness ◽  
Network Analyzer ◽  
Horn Antennas ◽  
Rfid Tag ◽  
Chipless Rfid ◽  
Linearly Polarized ◽  
Set Up ◽  
Film Substrate

This paper presented a new design of bendable hexagonal resonator for chipless RFID tag. A linearly polarized plane wave and Radar Cross Section (RCS) probes were used in simulation set-up. The optimized resonator was fabricated on a thin fast-film substrate with dielectric constant, εr=2.7 and substrate thickness, t = 0.13 mm. The fabricated resonator consisted of 3 hexagonal slots which represented three bit 1s. The measurement was performed to validate the designed resonator. It was measured using two transmitting and receiving horn antennas along with the network analyzer. The measured magnitudes were-24.292 dB, -28.854 dB and-32.234 dB.

Structural and electrical properties of lithium cobalt nanoferrites prepared by sol–gel method

2015 ◽  
Vol 29 (01) ◽  
pp. 1450255
Author(s):  
Victory Maisnam ◽  
Mamata Maisnam ◽  
Sumitra Phanjoubam
Keyword(s):  
Dielectric Constant ◽  
Electrical Properties ◽  
Dielectric Loss ◽  
Ac Conductivity ◽  
Sol Gel ◽  
Interfacial Polarization ◽  
Frequency Variation ◽  
Gel Method ◽  
Sol Gel Method ◽  
Lithium Cobalt

Lithium cobalt nanoferrites having the compositional formula Li 0.5-x/2 Co x Fe 2.5-x/2 O 4 with x varying from 0.00 to 0.12 in steps of 0.03 were prepared by the chemical sol–gel method. Samples were heated at two different temperatures namely 300°C and 500°C for 4 h. Structural characterization of the samples was done using X-ray diffraction (XRD) technique and confirmed the formation of single phase with spinel structure in all the samples. From the XRD data, the lattice parameter was calculated and found to range from 82.87–83.35 nm while the crystallite size was found to be in the range 17–34 nm. Microstructural studies were carried out using the Scanning Electron Microscopy and revealed the microstructures with grain size ranging from 35–70 nm. Electrical properties like dielectric constant, dielectric loss and AC conductivity for these nanoferrites were investigated. The frequency variation of room temperature dielectric constant, dielectric loss and AC conductivity were studied in the frequency range 100 Hz–1 MHz, and a dispersive behavior was observed, which has been attributed to the Maxwell–Wagner type of interfacial polarization.

scholarly journals 26 GHz phase shifters for multi-beam nolen matrix towards fifth generation (5G) technology

2019 ◽  
Vol 8 (3) ◽  
pp. 1028-1035
Author(s):  
Norhudah Seman ◽  
Nazleen Syahira Mohd Suhaimi ◽  
Tien Han Chua
Keyword(s):  
Dielectric Constant ◽  
Microstrip Line ◽  
Return Loss ◽  
Phase Shifter ◽  
Low Cost ◽  
Phase Shifters ◽  
Substrate Thickness ◽  
Fifth Generation ◽  
Compact Size ◽  
Better Than

This paper presents the designs of phase shifters for multi-beam Nolen matrix towards the fifth generation (5G) technology at 26 GHz. The low-cost, lightweight and compact size 0° and 45° loaded stubs and chamfered 90°, 135° and 180° Schiffman phase shifters are proposed at 26 GHz. An edge at a corner of the 50 Ω microstrip line Schiffman phase shifter is chamfered to reduce the excess capacitance and unwanted reflection. However, the Schiffman phase shifter topology is not relevant to be applied for the phase shifter less than 45° as it needs very small arc bending at 26 GHz. The stubs are loaded to the phase shifter in order to obtain electrical lengths, which are less than 45°. The proposed phase shifters provide return loss better than 10 dB, insertion loss of -0.97 dB and phase difference imbalance of ± 4.04° between 25.75GHz and 26.25 GHz. The Rogers RT/duroid 5880 substrate with dielectric constant of 2.2 and substrate thickness of 0.254 mm is implemented in the designs.

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