Magnetic trace suppression techniques and SQUID (Superconducting QUantum Interference Devices) technology in submarines

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Blog post on the subject

Implementation of a superconducting monolithic 10X10 imaging matrix using standart foundry processes developed for SFQ circuits

Implementation of a monolithic digital SQUID by using standard foundry processes.


And national SQUID technology
 

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Quantum magnetometer arrays for magnetic detection of submarines​

August 22, 2017

On 21 June, the Chinese Academy of Sciences hailed a breakthrough – a major upgrade to a kind of quantum device that measures magnetic fields. Magnetometers have been used to detect submarines since the second world war. They are able to do this because they can measure an anomaly in Earth’s magnetic field – like one caused by a massive hunk of metal.

The new magnetometer, built by Xiaoming Xie and colleagues at the Shanghai Institute of Microsystem and Information Technology, uses not one SQUID but an array of them. The idea is that by comparing their readings, researchers can cancel out some of the extra artefacts generated by motion. This “would be relevant to an anti-submarine warfare device”, says David Caplin at Imperial College London, who works on magnetic sensors.

Researchers estimate that a SQUID magnetometer of this type could detect a sub from 6 kilometres away, and Caplin says that with better noise suppression the range could be much greater.

Researchers report a low-temperature-superconducting (LTS) SQUID based full tensor gradient system. A symmetrical configuration is used with six planar-type gradiometers mounted on the different faces of a hexagonal-pyramid. A tri-axial SQUID magnetometer was used to compensate the imbalance outputs of each planar gradiometer. Direct readout electronics are used to further increase the system robustness. The SQUID outputs are synchronized with a GPS + INS unit for coordinate projection. During indoor tests, a noise level of 100fT/m/√Hz with corner frequency at 10Hz and a static RMS resolution of 10pT/m(0.01-10Hz) were achieved. Principle demonstration was carried out by a ground test over a 10×10 m2 area using buried iron balls with different weights. The system successfully resolved the abnormalities of all the gradient components at the corresponding locations. The field test was also carried out using a helicopter.

72a608ae0fdbbbeaef28aa8fae3e3abe.png

Magnetic Anomaly Detection (MAD) employs magnetometers to detect very small changes in the earth’s magnetic field. They are used for geophysical mineral and oil exploration, archeology, environmental surveys, ordnance and weapons detection (UXO), maritime intrusion detection, Anti-Submarine Warfare (ASW), and earth science experiments.

Compact, low power, temperature tolerant magnetometers such as the flux-gate design lack sensitivity, while the sensitive instruments based on molten potassium or cryogenic superconducting quantum interference devices (SQUIDs) require bulky insulation and significant resources to maintain their operating temperature.

69d53ac79404252ab2ac2dad9bd6cf4a.png


0bfd38978c618b1a5ecf2ae3922b3f7e.png

The Mechanical Expansion Amplifier (MEA) configured as a magnetometer provides a low-powered, ultra-sensitive magnetometer that can operate at any temperature in the -40C to +85C range with little change in sensitivity. The inherent noise limit is lower than that of the SQUIDs.

The Gotland-class submarine has a hastalloy stainless steel hull. It has a magnetic susceptibility similar of +2000e-6/cubic meter.

The submarine is equipped with electromagnets to reduce its magnetic signature. Assume the compensation is 99% effective in masking its effect on the earth’s magnetic field. The MEA magnetometer is assumed to be equipped with a complete suite of noise suppression systems.

For more comprehensive technical articles on the subject
Again, those who wish can download the relevant articles themselves.
 

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Adaptive metasurface designs for thermal camouflage, radiative cooling, and photodetector applications​


Bilkent University

Writer​

Buhara, Ebru

Advisor​

Özbay, Ekmel


Metamaterials, described as artificial sub-wavelength nanostructures, refer to a class of manufactured materials that possess distinctive electromagnetic features which cannot be found with natural materials. Thermal tunability, negative re-fractive index, perfect absorption, and invisible cloaking are examples of these attributes. Here, we design and implement metamaterials in four important ap-plication areas, namely 1) Multi-spectral infrared camouflage through excitation of plasmon-phonon polaritons in a visible-transparent hBN-ITO nanoantenna emitter, 2) Adaptive visible and short-wave infrared camouflage using a dynami-cally tunable metasurface, 3) Mid-infrared adaptive thermal camouflage using a phase-change material coupled dielectric nanoantenna, 4) An All-Dielectric Meta-surface Coupled with Two-Dimensional Semiconductors for Thermally Tunable Ultra-narrowband Light Absorption. In the first work, a metasurface design is developed to provide adaptive camou-flage in both visible and SWIR ranges. The proposed metasurface is made of an indium tin oxide (ITO) grating on a metal-insulator-metal (MIM, Ag-Sb2S3-Ag) nanocavity. In the amorphous state, the design operates as a colored transmis-sive window while, in the crystalline phase, it switches into a reflective mirror. In the meantime, the cavity acts as a thermally tunable host for the ITO nanoan-tenna providing tunable SWIR absorption to cover two transmissive regions at 1150-1350 nm (Region I) and 1400-1700 nm (Region II). It is found that the excitation of extended surface plasmons (ESPs) and guided mode resonances (GMRs) are responsible for light absorption in the SWIR range. Our theoretical calculations show that, besides the design’s ability for color adoption, the SWIR reflectance in Region I/Region II are reduced to 0.37/0.53 and 0.75/0.25 in the amorphous/crystalline phases. In the second work, a hybrid nanoantenna architecture made of ITO-hBN grating is proposed to satisfy all multi-spectral camouflage requirements. In this design, simultaneous excitation of plasmon-phonon polaritons in ITO and hBN leads to broadband absorption in the NTIR range and reflection in MWIR and LWIR ranges. Moreover, the bulk absorption in ITO film provides SWIR mode camouflage. Moreover, to highlight the importance of this hybrid design, the ITO-hBN design is compared with ITO-TiO2 heterostructure(TiO2 is a lossless dielectric in our desired ranges). Finally, the camouflage performance of the meta-surface is evaluated as the outgoing emission suppression when the metasurface design is on top of the blackbody object. In the third work, a PCM-dielectric based metasurface nanoantenna emitter design is proposed to achieve low observability at the MIR region by tailoring the spectral emissivity of the design. The proposed thermal nanoantenna emitter is composed of a high index dielectric (silicon (Si) in our case) nanograting on top of a thick silver (Ag) mirror. An ultrathin VO2 interlayer is embedded within the grating to actively tune its absorption response. The design geometries are adopted to place the resonance wavelengths in the atmospheric absorption win-dows for thermal camouflage applications. Based on the position of the VO2 layer, the optical response of the design in the metal phase can be diversely tuned from a narrowband to a broadband thermal emitter. Therefore, upon increase in the surface temperature, the proposed metasurface based thermal nanoantenna emitter turns into a broadband emitter with a stronger radiative thermal emission while it compatibly releases its heat based on the camouflage technology require-ment. The proposed design has perfect matching with atmospheric absorption windows so that it can efficiently release its heat without being observed by ther-mal camera systems. The detectability of the structure by a possible IR sensor is calculated using power calculations over the selected spectra. In addition, due to the hysteresis behavior of VO2, the calculations are done separately for cooling and heating conditions. In the fourth and final work, a dielectric based metasurface platform is pro-posed to achieve ultra-narrowband light absorption within a monolayer thick TMDC layer. For this purpose, the metasurface design is optimized. Then, this design is coupled with mono and multilayer TMDCs to observe better absorption results. For this purpose, MoS2, and WS2 are chosen as the most commonly used TMDCs. The coupling of light into Mie resonances, supported by dielec-tric nanograting, provides narrowband absorption within the TMDC layer. To reach further enhancement, a cavity design is integrated into this dielectric-based metasurface. For the best optimized design, the absorptance efficiency reaches to 0.85 and FWHM stays as narrow as 3.1 nm. Finally, the thermal tunability char-acteristic of the design is shown, without use of any phase change material. This is achieved due to strong light confinement within the design. Due to this con-finement, any small change in the refractive index is seen by the resonant design. Thus, the resonance frequency shifts and thermal tunability is acquired. The thermal sensitivity of the above-mentioned optimized design reaches to 0.0096 nm/◦C.


Color generation and enhancement using large-scale compatible metamaterial design architectures​


Writer​

Köşger, Ali Cahit

Advisor​

Özbay, Ekmel

Metamaterials are a type of artificial matt that can impose exotic functionalities beyond natural materials. These specifically designed sub-wavelength structures acquire these functionalities from their collective geometric arrangement rather than their individual single-unit properties. As a result, metamaterials have shown promising applications, including negative refraction, artificial magnetism, asymmetric transmission, lasing, and cloak of invisibility. Among all these applications, the concept of color generation and enhancement using metamaterial designs have attracted much attention in recent years. We can achieve color generation from two primary sources: i) filtering white light, and ii) generating light from emitting materials such as quantum dots. In color generation using white light, a metamaterial design reflects or transmits a narrow portion of the incident spectrum. Thus, the design acts as a color filter. However, the source is already a narrowband color light in the second category. Thus metamaterials merely amplify the color intensity rather than manipulate its spectral response. In this thesis, metamaterial structures are designed, fabricated, and characterized in both categories mentioned above; The content of this thesis consists of two parts; i) In the first part, we generated additive red-green-blue (RGB) colors in reflectance mode with near-unity amplitude. For this purpose, we designed a multilayer structure made of metal-insulator-metal-semiconductor-insulator (MIMSI) stacks to achieve >0.9 reflection peaks with full-width-at-half-maximum (FWHM) values <0.3λpeak. The proposed design also shows near-zero reflection in off-resonance spectral ranges, which, in turn, leads to high color purity. Finally, we fabricated the optimized designs and verified the simulation and theoretical results with characterization findings. This work demonstrates the potential of multilayer tandem cavity designs in realizing lithography-free large-scale compatible functional optical coatings. ii) In the second part, we utilized a large-scale compatible plasmonic nanocavity design platform to achieve almost an order of magnitude photoluminescence enhancement from light-emitting quantum dots. The proposed design is multi-sized/multi-spacing gold (Au) nano units that are uniformly wrapped with thin aluminum oxide (Al2O3) layer as a foreign host to form a metal-insulator-semiconductor (MIS) cavity, as we coated them with semiconductor quantum dots (QDs). Our numerical and experimental data demonstrate that, in an optimal insulator layer thickness, the simultaneous formation of broadband Fabry-Perot (FP) resonances and plasmonic hot spots leads to enhanced light absorption within the QD unit. This improvement in absorption response leads to the PL enhancement of QDs. This work demonstrates the potential and effectiveness of a host comprised of random plasmonic nanocavities in the realization of lithography-free efficient emitters. Overall, this thesis presents an alternative perspective on applying large-scale compatible metamaterials in color generation. Furthermore, the proposed designs and routes can be extended toward other functional photoelectronic designs, where high performances can be acquired in scaleable architectures.

These are the future Turkish stealth technologies, folks.

@Cabatli_TR @Anmdt @Combat-Master @Mis_TR_Like @TR-123456 @Zafer @Stuka
 

Bogeyman 

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Adaptive metasurface designs for thermal camouflage, radiative cooling, and photodetector applications​


Bilkent University

Writer​

Buhara, Ebru

Advisor​

Özbay, Ekmel


Metamaterials, described as artificial sub-wavelength nanostructures, refer to a class of manufactured materials that possess distinctive electromagnetic features which cannot be found with natural materials. Thermal tunability, negative re-fractive index, perfect absorption, and invisible cloaking are examples of these attributes. Here, we design and implement metamaterials in four important ap-plication areas, namely 1) Multi-spectral infrared camouflage through excitation of plasmon-phonon polaritons in a visible-transparent hBN-ITO nanoantenna emitter, 2) Adaptive visible and short-wave infrared camouflage using a dynami-cally tunable metasurface, 3) Mid-infrared adaptive thermal camouflage using a phase-change material coupled dielectric nanoantenna, 4) An All-Dielectric Meta-surface Coupled with Two-Dimensional Semiconductors for Thermally Tunable Ultra-narrowband Light Absorption. In the first work, a metasurface design is developed to provide adaptive camou-flage in both visible and SWIR ranges. The proposed metasurface is made of an indium tin oxide (ITO) grating on a metal-insulator-metal (MIM, Ag-Sb2S3-Ag) nanocavity. In the amorphous state, the design operates as a colored transmis-sive window while, in the crystalline phase, it switches into a reflective mirror. In the meantime, the cavity acts as a thermally tunable host for the ITO nanoan-tenna providing tunable SWIR absorption to cover two transmissive regions at 1150-1350 nm (Region I) and 1400-1700 nm (Region II). It is found that the excitation of extended surface plasmons (ESPs) and guided mode resonances (GMRs) are responsible for light absorption in the SWIR range. Our theoretical calculations show that, besides the design’s ability for color adoption, the SWIR reflectance in Region I/Region II are reduced to 0.37/0.53 and 0.75/0.25 in the amorphous/crystalline phases. In the second work, a hybrid nanoantenna architecture made of ITO-hBN grating is proposed to satisfy all multi-spectral camouflage requirements. In this design, simultaneous excitation of plasmon-phonon polaritons in ITO and hBN leads to broadband absorption in the NTIR range and reflection in MWIR and LWIR ranges. Moreover, the bulk absorption in ITO film provides SWIR mode camouflage. Moreover, to highlight the importance of this hybrid design, the ITO-hBN design is compared with ITO-TiO2 heterostructure(TiO2 is a lossless dielectric in our desired ranges). Finally, the camouflage performance of the meta-surface is evaluated as the outgoing emission suppression when the metasurface design is on top of the blackbody object. In the third work, a PCM-dielectric based metasurface nanoantenna emitter design is proposed to achieve low observability at the MIR region by tailoring the spectral emissivity of the design. The proposed thermal nanoantenna emitter is composed of a high index dielectric (silicon (Si) in our case) nanograting on top of a thick silver (Ag) mirror. An ultrathin VO2 interlayer is embedded within the grating to actively tune its absorption response. The design geometries are adopted to place the resonance wavelengths in the atmospheric absorption win-dows for thermal camouflage applications. Based on the position of the VO2 layer, the optical response of the design in the metal phase can be diversely tuned from a narrowband to a broadband thermal emitter. Therefore, upon increase in the surface temperature, the proposed metasurface based thermal nanoantenna emitter turns into a broadband emitter with a stronger radiative thermal emission while it compatibly releases its heat based on the camouflage technology require-ment. The proposed design has perfect matching with atmospheric absorption windows so that it can efficiently release its heat without being observed by ther-mal camera systems. The detectability of the structure by a possible IR sensor is calculated using power calculations over the selected spectra. In addition, due to the hysteresis behavior of VO2, the calculations are done separately for cooling and heating conditions. In the fourth and final work, a dielectric based metasurface platform is pro-posed to achieve ultra-narrowband light absorption within a monolayer thick TMDC layer. For this purpose, the metasurface design is optimized. Then, this design is coupled with mono and multilayer TMDCs to observe better absorption results. For this purpose, MoS2, and WS2 are chosen as the most commonly used TMDCs. The coupling of light into Mie resonances, supported by dielec-tric nanograting, provides narrowband absorption within the TMDC layer. To reach further enhancement, a cavity design is integrated into this dielectric-based metasurface. For the best optimized design, the absorptance efficiency reaches to 0.85 and FWHM stays as narrow as 3.1 nm. Finally, the thermal tunability char-acteristic of the design is shown, without use of any phase change material. This is achieved due to strong light confinement within the design. Due to this con-finement, any small change in the refractive index is seen by the resonant design. Thus, the resonance frequency shifts and thermal tunability is acquired. The thermal sensitivity of the above-mentioned optimized design reaches to 0.0096 nm/◦C.


Color generation and enhancement using large-scale compatible metamaterial design architectures​


Writer​

Köşger, Ali Cahit

Advisor​

Özbay, Ekmel

Metamaterials are a type of artificial matt that can impose exotic functionalities beyond natural materials. These specifically designed sub-wavelength structures acquire these functionalities from their collective geometric arrangement rather than their individual single-unit properties. As a result, metamaterials have shown promising applications, including negative refraction, artificial magnetism, asymmetric transmission, lasing, and cloak of invisibility. Among all these applications, the concept of color generation and enhancement using metamaterial designs have attracted much attention in recent years. We can achieve color generation from two primary sources: i) filtering white light, and ii) generating light from emitting materials such as quantum dots. In color generation using white light, a metamaterial design reflects or transmits a narrow portion of the incident spectrum. Thus, the design acts as a color filter. However, the source is already a narrowband color light in the second category. Thus metamaterials merely amplify the color intensity rather than manipulate its spectral response. In this thesis, metamaterial structures are designed, fabricated, and characterized in both categories mentioned above; The content of this thesis consists of two parts; i) In the first part, we generated additive red-green-blue (RGB) colors in reflectance mode with near-unity amplitude. For this purpose, we designed a multilayer structure made of metal-insulator-metal-semiconductor-insulator (MIMSI) stacks to achieve >0.9 reflection peaks with full-width-at-half-maximum (FWHM) values <0.3λpeak. The proposed design also shows near-zero reflection in off-resonance spectral ranges, which, in turn, leads to high color purity. Finally, we fabricated the optimized designs and verified the simulation and theoretical results with characterization findings. This work demonstrates the potential of multilayer tandem cavity designs in realizing lithography-free large-scale compatible functional optical coatings. ii) In the second part, we utilized a large-scale compatible plasmonic nanocavity design platform to achieve almost an order of magnitude photoluminescence enhancement from light-emitting quantum dots. The proposed design is multi-sized/multi-spacing gold (Au) nano units that are uniformly wrapped with thin aluminum oxide (Al2O3) layer as a foreign host to form a metal-insulator-semiconductor (MIS) cavity, as we coated them with semiconductor quantum dots (QDs). Our numerical and experimental data demonstrate that, in an optimal insulator layer thickness, the simultaneous formation of broadband Fabry-Perot (FP) resonances and plasmonic hot spots leads to enhanced light absorption within the QD unit. This improvement in absorption response leads to the PL enhancement of QDs. This work demonstrates the potential and effectiveness of a host comprised of random plasmonic nanocavities in the realization of lithography-free efficient emitters. Overall, this thesis presents an alternative perspective on applying large-scale compatible metamaterials in color generation. Furthermore, the proposed designs and routes can be extended toward other functional photoelectronic designs, where high performances can be acquired in scaleable architectures.

These are the future Turkish stealth technologies, folks.

@Cabatli_TR @Anmdt @Combat-Master @Mis_TR_Like @TR-123456 @Zafer @Stuka
Highly Tunable Diamond Shaped Metamaterial Resonator with Varactor Diodes

A Low Profile Antenna with Ultra-wideband Low Radar Cross Section Characteristic Based on Coding Metasurface​


In this article, we propose a design of aperture coupled antenna with ultra-wideband low radar cross section (RCS) characteristics for X band applications. The RCS reduction ranging from 8 to 24 GHz has been realized with two novel artificial magnetic conductor (AMC) unit cells that are placed around the patch antenna. The AMCs have been designed with a 180 ± 38° phase difference within a frequency range in order to provide an effective phase cancellation. The proposed antenna's operating bandwidth is 8.9-9.8 GHz, corresponding to an impedance bandwidth of 9.6%, and the RCS reduction is mainly in the Ku band. The maximum out-of-band RCS reduction is 37 dB at 12.7 GHz, while the maximum in-band RCS reduction is 27 dB at 9.2 GHz. The monostatic RCS results of the reference antenna and proposed antenna have been investigated under both θ and φ-polarized plane wave incidence.

Comparative Analysis in Radar Cross Section of Low Profile and Conventionally Sized UHF SATCOM Antenna​


In this paper, we show and compare the results in radar cross-section (RCS) between metamaterial-based λlow/40 low profile tactical UHF SATCOM antenna, operates in the band of 245 MHz - 310 MHz, and conventionally λ/4 sized aperture. The monostatic RCS results of both differently sized apertures have been examined in the frequency range of the S-band, under both θ and φ -polarized plane wave incidence angle up to 60°. A reduction of one-tenth in antenna profile yields a considerable decrease in RCS.

ASELSAN's article on metamaterials and lowering RCS values

Investigation of In-Gap Field Enhancement at Terahertz Frequencies for a Metasurface Enhanced Sensor​


The arrangements of subwavelength inclusions in a metasurface can serve as an effective absorber for the terahertz region. When such an absorber is combined with a unique material, the absorption can induce effects that can lead to a change in the materials electrical properties. Vanadium dioxide shows a passive and reversible change from monoclinic insulator phase to metallic tetragonal rutile structure by using external stimuli such as temperature (340K), photo excitation, electric field, mechanical strain or magnetic field [1] , [2] . Upon absorption of the THz radiation, the high electric fields that are generated inside the gaps of the metasurface can serve as trigger points, as was shown previously using kV strength THz E-fields [1] . By designing a better sensor which takes advantage of this non-linear enhancement one can lower this value to more accessible THz electric field strengths. In this work by utilizing various metasurface designs we examined the insulator to metal transition in VO 2 when illuminated by THz radiation. Gaps whose lengths were varied as 0.5, 1, 1.5µm that are oriented perpendicularly to the polarized THz fields served as field enhancement centers. Single and double notched gaps are compared and their respective in-gap field enhancements are calculated. In the single notched structure maximum in gap field enhancement value is obtained as nearly 100 for a 1.0µm gap size. For the double notched structure in gap field enhancement values are almost the same and maximum is obtained for 0.5µm at nearly 180 for both gaps. The change in enhancement shows that the non-linear enhancement is highly dependent on the geometry of the electrodes for a fixed unit cell wall thickness. Such enhancements can be exploited in designing sensitive sensors in the low frequency THz region.


Cumali Sabah's study on the absorption of Terahertz wavelength radiation with metamaterials at METU
 

Bogeyman 

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Highly Tunable Diamond Shaped Metamaterial Resonator with Varactor Diodes

A Low Profile Antenna with Ultra-wideband Low Radar Cross Section Characteristic Based on Coding Metasurface​


In this article, we propose a design of aperture coupled antenna with ultra-wideband low radar cross section (RCS) characteristics for X band applications. The RCS reduction ranging from 8 to 24 GHz has been realized with two novel artificial magnetic conductor (AMC) unit cells that are placed around the patch antenna. The AMCs have been designed with a 180 ± 38° phase difference within a frequency range in order to provide an effective phase cancellation. The proposed antenna's operating bandwidth is 8.9-9.8 GHz, corresponding to an impedance bandwidth of 9.6%, and the RCS reduction is mainly in the Ku band. The maximum out-of-band RCS reduction is 37 dB at 12.7 GHz, while the maximum in-band RCS reduction is 27 dB at 9.2 GHz. The monostatic RCS results of the reference antenna and proposed antenna have been investigated under both θ and φ-polarized plane wave incidence.

Comparative Analysis in Radar Cross Section of Low Profile and Conventionally Sized UHF SATCOM Antenna​


In this paper, we show and compare the results in radar cross-section (RCS) between metamaterial-based λlow/40 low profile tactical UHF SATCOM antenna, operates in the band of 245 MHz - 310 MHz, and conventionally λ/4 sized aperture. The monostatic RCS results of both differently sized apertures have been examined in the frequency range of the S-band, under both θ and φ -polarized plane wave incidence angle up to 60°. A reduction of one-tenth in antenna profile yields a considerable decrease in RCS.

ASELSAN's article on metamaterials and lowering RCS values

Investigation of In-Gap Field Enhancement at Terahertz Frequencies for a Metasurface Enhanced Sensor​


The arrangements of subwavelength inclusions in a metasurface can serve as an effective absorber for the terahertz region. When such an absorber is combined with a unique material, the absorption can induce effects that can lead to a change in the materials electrical properties. Vanadium dioxide shows a passive and reversible change from monoclinic insulator phase to metallic tetragonal rutile structure by using external stimuli such as temperature (340K), photo excitation, electric field, mechanical strain or magnetic field [1] , [2] . Upon absorption of the THz radiation, the high electric fields that are generated inside the gaps of the metasurface can serve as trigger points, as was shown previously using kV strength THz E-fields [1] . By designing a better sensor which takes advantage of this non-linear enhancement one can lower this value to more accessible THz electric field strengths. In this work by utilizing various metasurface designs we examined the insulator to metal transition in VO 2 when illuminated by THz radiation. Gaps whose lengths were varied as 0.5, 1, 1.5µm that are oriented perpendicularly to the polarized THz fields served as field enhancement centers. Single and double notched gaps are compared and their respective in-gap field enhancements are calculated. In the single notched structure maximum in gap field enhancement value is obtained as nearly 100 for a 1.0µm gap size. For the double notched structure in gap field enhancement values are almost the same and maximum is obtained for 0.5µm at nearly 180 for both gaps. The change in enhancement shows that the non-linear enhancement is highly dependent on the geometry of the electrodes for a fixed unit cell wall thickness. Such enhancements can be exploited in designing sensitive sensors in the low frequency THz region.


Cumali Sabah's study on the absorption of Terahertz wavelength radiation with metamaterials at METU
@Cabatli_TR @Anmdt @Combat-Master @Mis_TR_Like @TR-123456 @Zafer @Stuka
@Yasar @OPTIMUS
 
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Wideband Microwave Absorber Comprising Metallic Split-Ring Resonators Surrounded With E-Shaped Fractal Metamaterial​


A specially designed metallic E-shaped fractal-based perfect metamaterial absorber (PMA) with fairly wideband absorptivity in the K- and Ka-bands of the microwave regime was investigated. The PMA top surface is comprised of square-shaped split-ring resonators (SRRs) surrounded with the stated fractal design. The absorptivity of PMA was analyzed in the range of 20 - 30 GHz for the normal and oblique incidence of waves. Both the transverse electric (TE) and transverse magnetic (TM) modes were taken up to observe the robustness of the proposed design. It was observed that the fractal resonators exhibit capacitive effect at low frequencies, whereas the SRRs manifest capacitive effect at higher frequencies. The simulation and measured results were found to be in fairly good agreement. It is expected that the proposed design of PMA would be useful for 5G communication applications.

I think Mr. Cumali can use metamaterials as a passive measure against microwave weapons.
 

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TÜBİTAK BİLGEM Institute Deputy Director Dr. An interview with İlhan Kubilay Yalçın

"At the last point, we added Multi Static radar and Metamaterial Radar to our radar roadmap. We implement hybrid architectures modularly in phased array radar design.



Information note

Metamaterial Antennas, one of the innovative phased array radar technologies,
are one of the most surprising developments in recent times. In this new technology, which is also being studied in BİLGEM in our country, analog phase delay structures are miniaturized and lined up on the antenna and produced as an antenna plate.



Electromagnetic Metamaterials: A New Paradigm of Antenna Design​


Abstract:
The progress of technology in consumer electronics demand an antenna having a compact size, high gain and bandwidth, and multiple antennas at transmitter and receiver to enhance the channel capacity. Over the last decade, numerous techniques are proposed to improve the performance of the antenna. One such technique is the use of metamaterials (MTMs) in antenna design. MTMs are artificial structures to provide unique electromagnetic properties that are not available in natural materials. The unique properties of these materials allow the design of high-performance antennas, filters, and microwave devices which cannot be obtained using traditional antennas. Loading antenna with the one, two, and three-dimensional MTM structures comprised of a periodic subwavelength unit cell exhibits RLC resonant structures and allows to manipulate electromagnetic waves in the antenna system. These structures offer low resonant frequency compared to the antenna resonant frequency resulting in antenna miniaturization and manipulation of electromagnetic waves helps in enhancing the gain and bandwidth, and achieving circular polarization (CP) of an antenna system. Also, metamaterial loading enhances isolation between the antenna elements in the multiple-input-multiple output (MIMO) system by suppressing the surface waves. In this paper, the electromagnetics of MTM with analytical expressions and its application in antenna design are discussed in detail. The MTM-based antennas are classified into MTM loading, MTM inspired antenna, metasurface loading, and composite right/left hand (CRLH) based antennas. The recent development in MTM inspired antenna and its application in antenna miniaturization, enhancing gain and bandwidth, achieving CP and mutual coupling suppression in MIMO antenna systems are discussed to make it useful for further research.

I found a detailed article for friends who are familiar with radars made with metamaterials for the first time.

@Anmdt @Cabatli_TR @TR_123456 @Mis_TR_Like @Test7 @Yasar @Zafer @Combat-Master @TheInsider @Stimpy75 @Stuka @OPTIMUS
 

Zafer

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Electromagnetic Metamaterials: A New Paradigm of Antenna Design​


Abstract:
The progress of technology in consumer electronics demand an antenna having a compact size, high gain and bandwidth, and multiple antennas at transmitter and receiver to enhance the channel capacity. Over the last decade, numerous techniques are proposed to improve the performance of the antenna. One such technique is the use of metamaterials (MTMs) in antenna design. MTMs are artificial structures to provide unique electromagnetic properties that are not available in natural materials. The unique properties of these materials allow the design of high-performance antennas, filters, and microwave devices which cannot be obtained using traditional antennas. Loading antenna with the one, two, and three-dimensional MTM structures comprised of a periodic subwavelength unit cell exhibits RLC resonant structures and allows to manipulate electromagnetic waves in the antenna system. These structures offer low resonant frequency compared to the antenna resonant frequency resulting in antenna miniaturization and manipulation of electromagnetic waves helps in enhancing the gain and bandwidth, and achieving circular polarization (CP) of an antenna system. Also, metamaterial loading enhances isolation between the antenna elements in the multiple-input-multiple output (MIMO) system by suppressing the surface waves. In this paper, the electromagnetics of MTM with analytical expressions and its application in antenna design are discussed in detail. The MTM-based antennas are classified into MTM loading, MTM inspired antenna, metasurface loading, and composite right/left hand (CRLH) based antennas. The recent development in MTM inspired antenna and its application in antenna miniaturization, enhancing gain and bandwidth, achieving CP and mutual coupling suppression in MIMO antenna systems are discussed to make it useful for further research.

I found a detailed article for friends who are familiar with radars made with metamaterials for the first time.

@Anmdt @Cabatli_TR @TR_123456 @Mis_TR_Like @Test7 @Yasar @Zafer @Combat-Master @TheInsider @Stimpy75 @Stuka @OPTIMUS
Beyond 5G use of such materials will be inevitable.
 

Bogeyman 

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Wideband Microwave Absorber Comprising Metallic Split-Ring Resonators Surrounded With E-Shaped Fractal Metamaterial​


A specially designed metallic E-shaped fractal-based perfect metamaterial absorber (PMA) with fairly wideband absorptivity in the K- and Ka-bands of the microwave regime was investigated. The PMA top surface is comprised of square-shaped split-ring resonators (SRRs) surrounded with the stated fractal design. The absorptivity of PMA was analyzed in the range of 20 - 30 GHz for the normal and oblique incidence of waves. Both the transverse electric (TE) and transverse magnetic (TM) modes were taken up to observe the robustness of the proposed design. It was observed that the fractal resonators exhibit capacitive effect at low frequencies, whereas the SRRs manifest capacitive effect at higher frequencies. The simulation and measured results were found to be in fairly good agreement. It is expected that the proposed design of PMA would be useful for 5G communication applications.

I think Mr. Cumali can use metamaterials as a passive measure against microwave weapons.

Last year, I said that studies can be carried out in our country on absorbent materials against microwave weapons of microwave size. However, when I scanned the literature, I saw that a doctoral thesis was already written on the subject in 2014.

In the continuation publication of Dr. Mehmet Burak Kaynar in 2015, it was announced that the materials in question were superparamagnetic.

The article here says that superparamagnetic materials are one of the main components of RAM coatings.

F3HRPrsWsAI3_oE

F3HRE_YWoAACu3_

F3HRDKiXgAAzJZh


The company founded by Dr. Mehmet Burak Kaynar had already exhibited its low RCS values, low thermal trace, canopy and coating technologies at IDEF.

F3HSqdZWcAAgofV

F3HSsk3WMAML6qA

F3HSu1iXQAAQNsA


Canopy covering designs of our friends are also here


In the meantime, the company had a face-to-face meeting with Baykar Makine at the fair.

Dr. Mehmet Kaynar himself continues to work on radar absorbing materials.
 

Bogeyman 

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Last year, I said that studies can be carried out in our country on absorbent materials against microwave weapons of microwave size. However, when I scanned the literature, I saw that a doctoral thesis was already written on the subject in 2014.

In the continuation publication of Dr. Mehmet Burak Kaynar in 2015, it was announced that the materials in question were superparamagnetic.

The article here says that superparamagnetic materials are one of the main components of RAM coatings.

F3HRPrsWsAI3_oE

F3HRE_YWoAACu3_

F3HRDKiXgAAzJZh


The company founded by Dr. Mehmet Burak Kaynar had already exhibited its low RCS values, low thermal trace, canopy and coating technologies at IDEF.

F3HSqdZWcAAgofV

F3HSsk3WMAML6qA

F3HSu1iXQAAQNsA


Canopy covering designs of our friends are also here


In the meantime, the company had a face-to-face meeting with Baykar Makine at the fair.

Dr. Mehmet Kaynar himself continues to work on radar absorbing materials.
@Anmdt @Cabatli_TR @TR_123456 @Mis_TR_Like @Test7 @Yasar @Zafer @Combat-Master @TheInsider @Stimpy75 @Stuka @OPTIMUS @Ryder

Don't miss this guys
 

Bogeyman 

Experienced member
Professional
Messages
8,040
Reactions
57 28,553
Website
twitter.com
Nation of residence
Turkey
Nation of origin
Turkey
Last year, I said that studies can be carried out in our country on absorbent materials against microwave weapons of microwave size. However, when I scanned the literature, I saw that a doctoral thesis was already written on the subject in 2014.

In the continuation publication of Dr. Mehmet Burak Kaynar in 2015, it was announced that the materials in question were superparamagnetic.

The article here says that superparamagnetic materials are one of the main components of RAM coatings.

F3HRPrsWsAI3_oE

F3HRE_YWoAACu3_

F3HRDKiXgAAzJZh


The company founded by Dr. Mehmet Burak Kaynar had already exhibited its low RCS values, low thermal trace, canopy and coating technologies at IDEF.

F3HSqdZWcAAgofV

F3HSsk3WMAML6qA

F3HSu1iXQAAQNsA


Canopy covering designs of our friends are also here


In the meantime, the company had a face-to-face meeting with Baykar Makine at the fair.

Dr. Mehmet Kaynar himself continues to work on radar absorbing materials.
F3GKYgFWAAAKmek


Meanwhile, the US microwave weapon
 

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