Onion routing networks, or darknets, enable anonymous communication, protecting user privacy and attracting cybercriminals. This paper analyzes cybercrime in these networks, including drug trafficking, fraud, and hacking. The challenges seen in the detection and mitigation of these crimes arising as the result of strong anonymity and explore countermeasures such as law enforcement, technological solutions, and policy interventions have been discussed, as also highlighting of the limitations of current measures and proposals for future research, with emphasis on the need for interdisciplinary approaches combining technical, legal, and social perspectives.
{"title":"Cybersecurity in Onion Routing Environments: Strategies to Thwart Cyber Threats","authors":"Karwan Mustafa Kareem","doi":"10.58399/dnnc2284","DOIUrl":"https://doi.org/10.58399/dnnc2284","url":null,"abstract":"Onion routing networks, or darknets, enable anonymous communication, protecting user privacy and attracting cybercriminals. This paper analyzes cybercrime in these networks, including drug trafficking, fraud, and hacking. The challenges seen in the detection and mitigation of these crimes arising as the result of strong anonymity and explore countermeasures such as law enforcement, technological solutions, and policy interventions have been discussed, as also highlighting of the limitations of current measures and proposals for future research, with emphasis on the need for interdisciplinary approaches combining technical, legal, and social perspectives.","PeriodicalId":340688,"journal":{"name":"JOURNAL OF HIGH-FREQUENCY COMMUNICATION TECHNOLOGIES","volume":"63 14","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141798647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A linearly polarized wide bandpass frequency selective surface (FSS) for RADAR communication application has been presented. The proposed FSS is constructed in a single layer with a size of 0.25 λ0. This FSS utilizes a rhombus slot comprised of a head slot and a meander line to provide a single-wideband resonance. The proposed FSS operates in the X-band communication frequency range from 7.98 to 12.1 GHz (4.12 GHz) and achieves a minimum insertion loss of 0.1 dB, respectively. The designed FSS is developed on a flexible substrate with a low profile of 0.05 mm. The FSS exhibits stable angular performance in the scope of incidence angle of 60º for both TE and TM modes. An equivalent circuit model is designed to depict the desired frequency response. Furthermore, a bending analysis has been carried out to verify the conformal nature of the proposed unit cell. The prototype is fabricated and the performances are validated with experimental results.
本文介绍了一种用于雷达通信的线性极化宽带通频率选择表面（FSS）。所提出的 FSS 采用单层结构，尺寸为 0.25 λ0。该 FSS 利用由头部槽和蜿蜒线组成的菱形槽提供单宽带谐振。所提出的 FSS 工作在 7.98 至 12.1 GHz（4.12 GHz）的 X 波段通信频率范围内，并分别实现了 0.1 dB 的最小插入损耗。所设计的 FSS 是在 0.05 毫米低剖面柔性基板上开发的。在入射角为 60º 的范围内，FSS 对 TE 和 TM 模式均表现出稳定的角度性能。设计了一个等效电路模型来描述所需的频率响应。此外，还进行了弯曲分析，以验证拟议单元的保形性。原型已制作完成，其性能已通过实验结果验证。
{"title":"Novel Polyimide-Based Conformal Bandpass FSS for X-band RADAR Communications","authors":"Geethanjali Govindarajan, Preetha Purusothaman","doi":"10.58399/baag2904","DOIUrl":"https://doi.org/10.58399/baag2904","url":null,"abstract":"A linearly polarized wide bandpass frequency selective surface (FSS) for RADAR communication application has been presented. The proposed FSS is constructed in a single layer with a size of 0.25 λ0. This FSS utilizes a rhombus slot comprised of a head slot and a meander line to provide a single-wideband resonance. The proposed FSS operates in the X-band communication frequency range from 7.98 to 12.1 GHz (4.12 GHz) and achieves a minimum insertion loss of 0.1 dB, respectively. The designed FSS is developed on a flexible substrate with a low profile of 0.05 mm. The FSS exhibits stable angular performance in the scope of incidence angle of 60º for both TE and TM modes. An equivalent circuit model is designed to depict the desired frequency response. Furthermore, a bending analysis has been carried out to verify the conformal nature of the proposed unit cell. The prototype is fabricated and the performances are validated with experimental results.","PeriodicalId":340688,"journal":{"name":"JOURNAL OF HIGH-FREQUENCY COMMUNICATION TECHNOLOGIES","volume":"283 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140233344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The paper addresses the challenge of crosstalk in neighboring paths on PCBs, emphasizing its growing importance with the advancement of electronic circuits in terms of speed and frequency. The proposed solution involves the introduction of a novel W-shaped Defected Microstrip Structure (DMS) on a step-shaped coupled transmission lines to mitigate near-end crosstalk (NEXT) and far-end crosstalk (FEXT) using mixed signal input. A novel W-shaped defective microstrip structure (DMS) that is etched on step-shaped coupled transmission lines. The proposed technique focuses on minimizing the electromagnetic coupling strength with a minimum spacing of one time the width of the trace. It optimizes the ratio of capacitive coupling and inductive coupling between the coupled microstrip transmission lines to improve crosstalk. The frequency domain simulation, conducted using Computer Simulation Technology (CST), indicates promising results. The insertion loss (|S21|), near-end crosstalk (|S31|), and far-end crosstalk (|S41|) of the suggested structure are reported as 1.425dB, <25dB, and <25dB, respectively, over the frequency range of 0 to 10 GHz. Eye diagram characterizations are done and measured in terms of eye height, eye width, jitter and data rate are reported as 0.942V, 695.5ps, 6.69ps and 1.4Gbps respectively.
{"title":"On the Design of a Stepped Mixed Signal Transmission Line with Defected Microstrip Structure for High-Frequency PCB Traces","authors":"Y. V.","doi":"10.58399/rzrq1838","DOIUrl":"https://doi.org/10.58399/rzrq1838","url":null,"abstract":"The paper addresses the challenge of crosstalk in neighboring paths on PCBs, emphasizing its growing importance with the advancement of electronic circuits in terms of speed and frequency. The proposed solution involves the introduction of a novel W-shaped Defected Microstrip Structure (DMS) on a step-shaped coupled transmission lines to mitigate near-end crosstalk (NEXT) and far-end crosstalk (FEXT) using mixed signal input. A novel W-shaped defective microstrip structure (DMS) that is etched on step-shaped coupled transmission lines. The proposed technique focuses on minimizing the electromagnetic coupling strength with a minimum spacing of one time the width of the trace. It optimizes the ratio of capacitive coupling and inductive coupling between the coupled microstrip transmission lines to improve crosstalk. The frequency domain simulation, conducted using Computer Simulation Technology (CST), indicates promising results. The insertion loss (|S21|), near-end crosstalk (|S31|), and far-end crosstalk (|S41|) of the suggested structure are reported as 1.425dB, <25dB, and <25dB, respectively, over the frequency range of 0 to 10 GHz. Eye diagram characterizations are done and measured in terms of eye height, eye width, jitter and data rate are reported as 0.942V, 695.5ps, 6.69ps and 1.4Gbps respectively.","PeriodicalId":340688,"journal":{"name":"JOURNAL OF HIGH-FREQUENCY COMMUNICATION TECHNOLOGIES","volume":"3 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140432664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The design, fabrication, and testing of a highly sensitive GHz sensor for real-time measurement of engine oil quality are presented in this paper. The proposed microwave sensor is constructed on symmetric square slots structures, to improve the performance of the sensor. By using the resonant perturbation theory, the change in the max E field of test samples, produce the frequency shift. The footprint of the designed sensor is (0.5523λeff × 0.0920λeff) where λeff is the effective wavelength value calculated at the operating frequency of 5.52GHz. The oil sample adulteration analysis is done by immersion of a dielectric probe up to a reference level of 20 mm. Thus, the dielectric behavior of the sensor is estimated with an average sensitivity of 1.7. The performance of the microwave sensor is evaluated by submerging it in different engine oil samples, thereby resulting in frequency shifts from 5.53 to lower values. The result obtained from it indicated that the sensor has a quality factor of 54.55 and a FoM of 19.17. Thus, the proposed GHz sensor due to its good sensitivity, FoM, and quality factor is the eminent solution for the automobile industry.
{"title":"Design of Microwave Electromagnetic Sensor for Liquid Characterization","authors":"Jayadevan Arumugam, Naveen Raj Edhayaraj, Santhosh Shanmugavadivelu, Vidhyashree Sathyanarayanan","doi":"10.58399/tlcx9900","DOIUrl":"https://doi.org/10.58399/tlcx9900","url":null,"abstract":"The design, fabrication, and testing of a highly sensitive GHz sensor for real-time measurement of engine oil quality are presented in this paper. The proposed microwave sensor is constructed on symmetric square slots structures, to improve the performance of the sensor. By using the resonant perturbation theory, the change in the max E field of test samples, produce the frequency shift. The footprint of the designed sensor is (0.5523λeff × 0.0920λeff) where λeff is the effective wavelength value calculated at the operating frequency of 5.52GHz. The oil sample adulteration analysis is done by immersion of a dielectric probe up to a reference level of 20 mm. Thus, the dielectric behavior of the sensor is estimated with an average sensitivity of 1.7. The performance of the microwave sensor is evaluated by submerging it in different engine oil samples, thereby resulting in frequency shifts from 5.53 to lower values. The result obtained from it indicated that the sensor has a quality factor of 54.55 and a FoM of 19.17. Thus, the proposed GHz sensor due to its good sensitivity, FoM, and quality factor is the eminent solution for the automobile industry.","PeriodicalId":340688,"journal":{"name":"JOURNAL OF HIGH-FREQUENCY COMMUNICATION TECHNOLOGIES","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130327197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this manuscript, a compact dual reconfigurable monopole antenna is proposed. It operates at various frequencies depending upon the condition of the six operating conditions. The designed antenna exhibits dual reconfigurability, that is, frequency as well as pattern reconfigurability. This is done to increase the robustness of the proposed design. There are six lumped circuits in which each circuit consisting of two resistors, two capacitors and one diode. The antenna operates on the following resonant frequencies: 1.7 GHz, 2.45 GHz, 3.5 GHz and 5.2 GHz falling inside the application, such as WLAN and Wi-MAX ranges. This antenna due to its dual reconfigurability can be utilized in many areas, such as cognitive radio systems, mobile phones, etc. The reconfigurable antenna performance is examined under different states of diodes on the basis of the antenna parameters, such as return loss, radiation pattern and gain. The designed antenna exhibits dual reconfigurability; that is, frequency as well as pattern reconfigurability. The performance of the reconfigurable antenna under different states of diodes are examined.
{"title":"Design of Compact Dual Reconfigurable Antenna for WiMAX/WLAN Applications","authors":"Sangeetha Subbaraj, Anirudh E R","doi":"10.58399/kdhg4316","DOIUrl":"https://doi.org/10.58399/kdhg4316","url":null,"abstract":"In this manuscript, a compact dual reconfigurable monopole antenna is proposed. It operates at various frequencies depending upon the condition of the six operating conditions. The designed antenna exhibits dual reconfigurability, that is, frequency as well as pattern reconfigurability. This is done to increase the robustness of the proposed design. There are six lumped circuits in which each circuit consisting of two resistors, two capacitors and one diode. The antenna operates on the following resonant frequencies: 1.7 GHz, 2.45 GHz, 3.5 GHz and 5.2 GHz falling inside the application, such as WLAN and Wi-MAX ranges. This antenna due to its dual reconfigurability can be utilized in many areas, such as cognitive radio systems, mobile phones, etc. The reconfigurable antenna performance is examined under different states of diodes on the basis of the antenna parameters, such as return loss, radiation pattern and gain. The designed antenna exhibits dual reconfigurability; that is, frequency as well as pattern reconfigurability. The performance of the reconfigurable antenna under different states of diodes are examined.","PeriodicalId":340688,"journal":{"name":"JOURNAL OF HIGH-FREQUENCY COMMUNICATION TECHNOLOGIES","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132869079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
An Optically transparent UWB antenna with polarization diversity for the use of automotive communications is presented in this paper. The novel two element antenna operates at the frequency range of 2.5-8 GHz with dimension 45×45 mm2 and peak gain 1.2 dBi. Antenna elements are placed orthogonally to achieve polarisation diversity. The proposed antenna is placed on a soda lime glass substrate which has a permittivity of 7.3 and thickness of 2.2 mm. The radiator of the antenna is made of FTO with sheet resistance 6 Ω/sq. The Diversity gain of the proposed antenna is greater than 9.9 and ECC value is lesser than 0.02 for the frequency range of 3-8 GHz. The isolation between the antenna elements is more than 15 dB without any complex decoupling structures between them.
{"title":"Optically Transparent MIMO Antenna with Polarization Diversity","authors":"","doi":"10.58399/inhk8527","DOIUrl":"https://doi.org/10.58399/inhk8527","url":null,"abstract":"An Optically transparent UWB antenna with polarization diversity for the use of automotive communications is presented in this paper. The novel two element antenna operates at the frequency range of 2.5-8 GHz with dimension 45×45 mm2 and peak gain 1.2 dBi. Antenna elements are placed orthogonally to achieve polarisation diversity. The proposed antenna is placed on a soda lime glass substrate which has a permittivity of 7.3 and thickness of 2.2 mm. The radiator of the antenna is made of FTO with sheet resistance 6 Ω/sq. The Diversity gain of the proposed antenna is greater than 9.9 and ECC value is lesser than 0.02 for the frequency range of 3-8 GHz. The isolation between the antenna elements is more than 15 dB without any complex decoupling structures between them.","PeriodicalId":340688,"journal":{"name":"JOURNAL OF HIGH-FREQUENCY COMMUNICATION TECHNOLOGIES","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125704605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper reports the design, development, fabrication, and testing of a 225-element reconfigurable reflectarray (RRA) antenna with frequency agility and beam steering capabilities. The 15 15 (18.75 cm) RRA operating in the Ku band downlink frequency range (11.8 -12.2 GHz) of fixed satellite services (FSS) produces dual resonances switched between uplink frequency range (15-18 GHz) of FSS and earth exploration satellite range of 9.5-9.8 GHz (X Band). To attain reconfigurable multiple resonances, the unit cell is designed with a Malta cross of varying slot lengths interconnected to a square ring via a PIN diode. In the OFF state of the PIN diode connected between the concentric elements, a phase variation of 360° is obtained at 12 GHz and 9.5 GHz by varying the size of the Malta cross. By increasing the width of the outer ring in the ON state of the PIN diode, a dual resonance is obtained at 12 GHz and 17 GHz with 360° phase agility. The beam scanning is attempted at X band frequency by controlling the capacitance offered by the varactor diode connected between an inductive element and Malta cross. The proposed RRA offers 22.16 dBi, 24.5 dBi and 18.43 dBi simulated gain at 17 GHz, 12 GHz, and 9.5 GHz respectively. The simulated sidelobe levels (SLLs) and cross-polarization levels are -14.7 dB and less than -32 dB respectively. The proposed compound reconfigurable reflectarray befits fixed and mobile satellites, earth exploration satellites, radiolocation, aeronautical radio navigation, and deep space research.
{"title":"Electronically Controlled Frequency Agile Beam Scanning Reflectarray Antenna with Integrated Control Unit","authors":"Kavitha Narayanasamy, Kirubaveni Savarimuthu, Ikram Khan","doi":"10.58399/wxej1376","DOIUrl":"https://doi.org/10.58399/wxej1376","url":null,"abstract":"This paper reports the design, development, fabrication, and testing of a 225-element reconfigurable reflectarray (RRA) antenna with frequency agility and beam steering capabilities. The 15 15 (18.75 cm) RRA operating in the Ku band downlink frequency range (11.8 -12.2 GHz) of fixed satellite services (FSS) produces dual resonances switched between uplink frequency range (15-18 GHz) of FSS and earth exploration satellite range of 9.5-9.8 GHz (X Band). To attain reconfigurable multiple resonances, the unit cell is designed with a Malta cross of varying slot lengths interconnected to a square ring via a PIN diode. In the OFF state of the PIN diode connected between the concentric elements, a phase variation of 360° is obtained at 12 GHz and 9.5 GHz by varying the size of the Malta cross. By increasing the width of the outer ring in the ON state of the PIN diode, a dual resonance is obtained at 12 GHz and 17 GHz with 360° phase agility. The beam scanning is attempted at X band frequency by controlling the capacitance offered by the varactor diode connected between an inductive element and Malta cross. The proposed RRA offers 22.16 dBi, 24.5 dBi and 18.43 dBi simulated gain at 17 GHz, 12 GHz, and 9.5 GHz respectively. The simulated sidelobe levels (SLLs) and cross-polarization levels are -14.7 dB and less than -32 dB respectively. The proposed compound reconfigurable reflectarray befits fixed and mobile satellites, earth exploration satellites, radiolocation, aeronautical radio navigation, and deep space research.","PeriodicalId":340688,"journal":{"name":"JOURNAL OF HIGH-FREQUENCY COMMUNICATION TECHNOLOGIES","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128244555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kavitha Narayanaswamy, V. Suresh, Kirubaveni Savarimuthu, Ishwarya Balan
This paper presents the design of a frequency reconfigurable reflectarray with concentric circular rings. The PIN diode connected between a phase delay line and the ring produces reconfigured resonances at 16 GHz and 10.4 GHz. The variation in the size of the concentric rings offer a phase change of 356º during the OFF state of the PIN diode. 360° phase variation in the PIN ON condition is achieved by varying the delay line length. A 225-element centre-fed reflectarray antenna is constructed with square geometry. A simulated gain of 23 dBi is obtained with -17 dB side lobe level and -28 dB cross-polarization level at 16 GHz. In the PIN ON condition, a simulated gain of 22 dBi is obtained with -12 dB side lobe level and -28 dB cross polarization level. This reconfigurable reflectarray finds its applications in space research, satellite communication, and RADAR.
{"title":"Design and Development of Frequency Agile Reflectarray Antenna","authors":"Kavitha Narayanaswamy, V. Suresh, Kirubaveni Savarimuthu, Ishwarya Balan","doi":"10.58399/ajmc4517","DOIUrl":"https://doi.org/10.58399/ajmc4517","url":null,"abstract":"This paper presents the design of a frequency reconfigurable reflectarray with concentric circular rings. The PIN diode connected between a phase delay line and the ring produces reconfigured resonances at 16 GHz and 10.4 GHz. The variation in the size of the concentric rings offer a phase change of 356º during the OFF state of the PIN diode. 360° phase variation in the PIN ON condition is achieved by varying the delay line length. A 225-element centre-fed reflectarray antenna is constructed with square geometry. A simulated gain of 23 dBi is obtained with -17 dB side lobe level and -28 dB cross-polarization level at 16 GHz. In the PIN ON condition, a simulated gain of 22 dBi is obtained with -12 dB side lobe level and -28 dB cross polarization level. This reconfigurable reflectarray finds its applications in space research, satellite communication, and RADAR.","PeriodicalId":340688,"journal":{"name":"JOURNAL OF HIGH-FREQUENCY COMMUNICATION TECHNOLOGIES","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125931659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. Suresh, Aishika Bhattacharjee, Kirubaveni Savarimuthu
This paper presents a beam scanning electronically reconfigurable reflectarray configuration for Ku-band applications using a single varactor diode. A 15×15 center-fed reconfigurable reflectarray antenna is designed consisting of 225 octagonal shaped unit cells. The proposed tunable element has a unit cell size of 9.8 mm, developed on a 1.575 mm thick Taconic TLY-5 substrate. A single varactor diode is integrated with the tunable element to produce a reflection phase variation of 340° at 14.1 GHz. In this work, both the varactor and biasing circuit are placed beneath the substrate to avoid unexpected reflections, which leads to achieving a pencil beam of 8.1° beamwidth. The simulation results of the reconfigurable reflectarray antenna (RRA) shows good beam-scanning radiation performance of scanning range ±30° and a peak gain of 27.6 dBi. This structure provides a convenient solution for Ku-band distinctive applications like uplink operation in the direct broadcast satellite system, digital video broadcasting, earth exploration satellites, space research satellites, and defense systems.
{"title":"Dual-Layer Beamscanning Reflectarray Antenna Operating at Ku-Band","authors":"V. Suresh, Aishika Bhattacharjee, Kirubaveni Savarimuthu","doi":"10.58399/sulr8973","DOIUrl":"https://doi.org/10.58399/sulr8973","url":null,"abstract":"This paper presents a beam scanning electronically reconfigurable reflectarray configuration for Ku-band applications using a single varactor diode. A 15×15 center-fed reconfigurable reflectarray antenna is designed consisting of 225 octagonal shaped unit cells. The proposed tunable element has a unit cell size of 9.8 mm, developed on a 1.575 mm thick Taconic TLY-5 substrate. A single varactor diode is integrated with the tunable element to produce a reflection phase variation of 340° at 14.1 GHz. In this work, both the varactor and biasing circuit are placed beneath the substrate to avoid unexpected reflections, which leads to achieving a pencil beam of 8.1° beamwidth. The simulation results of the reconfigurable reflectarray antenna (RRA) shows good beam-scanning radiation performance of scanning range ±30° and a peak gain of 27.6 dBi. This structure provides a convenient solution for Ku-band distinctive applications like uplink operation in the direct broadcast satellite system, digital video broadcasting, earth exploration satellites, space research satellites, and defense systems.","PeriodicalId":340688,"journal":{"name":"JOURNAL OF HIGH-FREQUENCY COMMUNICATION TECHNOLOGIES","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122211242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The frequency reconfigurable reflectarray (RRA) reported in this paper provides a pencil beam at three frequencies captivating the need for satellite broadcast television at uplink and downlink frequencies in Ku band and X band. To achieve such frequency reconfiguration, a unit cell developed and simulated based on an infinite array approach is used in integration with four PIN diodes to produce a reflection phase variation of 525°, 415°, and 308° at 14.34 GHz for uplink operation, 12.2 GHz for downlink and 11.9 GHz for X-band performance respectively. In this proposed unit cell, the phase variation for uplink is achieved by varying the size of concentric loops, while in the case of downlink and X-band, reconfiguration controlled by pin diodes is achieved by varying the length of the delay line. With the periodicity of 0.49λ0 (10.5 mm), a 15 15 array with 225 elements is constructed using the designed unit cell on square planar geometry. The paper reports a maximum gain of 25.77 dBi, 25.13 dBi, and 22.7 dBi and 40.22%, 26.46%, and 25.36% of aperture efficiency at 14.34 GHz, 12.2 GHz, and 11.9 GHz respectively. A -3dB gain bandwidth of 8.37%, 4.92%, and 12.18% is achieved at the three operating frequencies by simulation. Hence this reconfigurable reflectarray serves as an emulous alternative to parabolic reflectors and phased array antennas in deep space communication and direct broadcast satellite applications satisfying the high gain pencil beam requirements.
{"title":"Optimum Design of a Novel Electronically Reconfigurable Reflectarray Antenna for X/Ku Band Applications","authors":"V. Suresh","doi":"10.58399/dauk9418","DOIUrl":"https://doi.org/10.58399/dauk9418","url":null,"abstract":"The frequency reconfigurable reflectarray (RRA) reported in this paper provides a pencil beam at three frequencies captivating the need for satellite broadcast television at uplink and downlink frequencies in Ku band and X band. To achieve such frequency reconfiguration, a unit cell developed and simulated based on an infinite array approach is used in integration with four PIN diodes to produce a reflection phase variation of 525°, 415°, and 308° at 14.34 GHz for uplink operation, 12.2 GHz for downlink and 11.9 GHz for X-band performance respectively. In this proposed unit cell, the phase variation for uplink is achieved by varying the size of concentric loops, while in the case of downlink and X-band, reconfiguration controlled by pin diodes is achieved by varying the length of the delay line. With the periodicity of 0.49λ0 (10.5 mm), a 15 15 array with 225 elements is constructed using the designed unit cell on square planar geometry. The paper reports a maximum gain of 25.77 dBi, 25.13 dBi, and 22.7 dBi and 40.22%, 26.46%, and 25.36% of aperture efficiency at 14.34 GHz, 12.2 GHz, and 11.9 GHz respectively. A -3dB gain bandwidth of 8.37%, 4.92%, and 12.18% is achieved at the three operating frequencies by simulation. Hence this reconfigurable reflectarray serves as an emulous alternative to parabolic reflectors and phased array antennas in deep space communication and direct broadcast satellite applications satisfying the high gain pencil beam requirements.","PeriodicalId":340688,"journal":{"name":"JOURNAL OF HIGH-FREQUENCY COMMUNICATION TECHNOLOGIES","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114383545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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