Vol. 115
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PIER Letters
Vol. 115, 105-109, 2024
download: 338
Multi-Channel Electromagnetic Filters Based on EIT and Fano Resonances through Parallel Segments and Asymmetric Resonators
Moulay Said Khattab , Tarik Touiss , Ilyass El Kadmiri , Fatima Zahra Elamri and Driss Bria
In this study, we investigate electromagnetically induced transparency (EIT) and Fano resonances, focusing on the propagation of electromagnetic waves in a system of parallel waveguides associated with asymmetric resonators. Our design includes five waveguides and two resonators, generating discrete modes influenced by their respective lengths. The EIT resonance is characterized by a prominent transmission peak flanked by two transmission zeros, while the Fano resonance is characterized by a pronounced transmission peak adjacent to a transmission zero. Using the transfer matrix method (TMM), we calculate transmission and reflection rates. Our results indicate that the EIT resonance appears when the resonator lengths show slight differences, whereas the Fano resonance appears when the resonator lengths are identical. Both resonances are sensitive to resonator lengths and permittivity indices. Consequently, the geometrical parameters of the system must be carefully selected according to the application in question, whether waveguiding or multi-channel electromagnetic filtering.
Multi-channel Electromagnetic Filters Based on EIT and Fano Resonances through Parallel Segments and Asymmetric Resonators
PIER Letters
Vol. 115, 99-104, 2024
download: 189
A Red Cross Bag MPA with a Very Low SAR and High F/b Ratio for Bio-Medical Applications
Anwer Sabah Mekki , Siba Monther Yousif and Saif Mohammed Baraa
A microstrip patch antenna of red cross bag shape is designed, simulated, and fabricated. The antenna is designed to work at 5.8 GHz for on-body applications. Small size, low specific absorption rate, and high front to back ratio with a low-profile design are achieved. The measured frequency is 5.878 GHz with 25 mm as the largest dimension used, and the matching impedance is -47.06 dB. Other parameters are recorded from the simulator, such as front-to-back ratio which is 37.37 dB and a specific absorption rate of 0.0984 W/kg in 10 gm. Finally, this work is compared with a compact dual-band antenna with paired L-shape slots, a watchstrap integrated wideband antenna, and a dual-band AMC-based MIMO. The proposed red cross bag antenna overcomes the mentioned works in terms of small size, high front-to-back ratio, and low specific absorption rate.
A Red Cross Bag MPA with a Very Low SAR and High F/B Ratio for Bio-medical Applications
PIER Letters
Vol. 115, 91-98, 2024
download: 132
A Low Side Lobe Level Parabolic Antenna for Meteorological Applications
András Eszes , Zsolt Szabó , Béla Ladányi-Turóczy and István Kalácska
A novel corrugated subreflector is developed to achieve sufficient side lobe level suppression for antenna systems used in meteorological applications. The subreflector operates at 9.41 GHz, with a 60 MHz bandwidth and an efficiency of more than 70%. Its structure is rotational symmetric and is suitable for parabolic antenna applications. It can be utilized in single-polarized or polarimetric radar systems. The pattern-forming property of the subreflector is achieved with corrugations of different depths. Analytical design formulas have been deduced by solving the aperture integral. The analytical formulas provide the initial geometrical configuration and the reference illumination pattern in the objective function to which full-wave electromagnetic optimizations are performed to obtain the final corrugation depths. The subreflector has been manufactured with CNC machining. The radiation characteristics are measured, and for both polarizations, suppression of -28 dB side lobe level has been achieved with a 1.2 m diameter main reflector.
A Low Side Lobe Level Parabolic Antenna for Meteorological Applications
PIER Letters
Vol. 115, 81-89, 2024
download: 113
A Novel Stacked Rectangular with Surface Mounted Short Rectangle Dielectric Resonator Antenna in C-Band Applications
Syamala Misala and Satya Anuradha Mosa
A novel stacked rectangular structure with surface-mounted short rectangle dielectric resonator antenna (SRSMSR) with an E-shaped microstrip feed through a wide aperture slot was investigated for C-band operation in wireless communication and tracking radar applications. The developed design uses copper for SMSR to improve return loss up to -46 dB, gain up to 10.7 dB, and an observed impedance bandwidth of 20.6% in the broad frequency range of 5.69 GHz-7.0 GHz. The 3 dB beam width achieved in the E-plane is 89.82˚, while that in the H-plane is 24.31˚.
A Novel Stacked Rectangular with Surface Mounted Short Rectangle Dielectric Resonator Antenna in C-band Applications
PIER Letters
Vol. 115, 71-79, 2024
download: 112
Influence of the Spatial Distribution of Molecular Magnetic Moments on the Radiation Characteristics of Rotating Permanent Magnet Antennas
Tiantian Li , Bin Li and Jin Meng
Taking into account the radiation characteristics of rotating permanent magnet antennas, the influence of the spatial distribution of molecular magnetic moments on the radiation characteristics was verified by performing theoretical calculations and simulations. First, the magnetic field distribution of arbitrarily shaped permanent magnets was derived based on the Biot-Savart Law, and the concentration degree of the molecular magnetic moments to the connection of the two magnetic poles and the comprehensive performance evaluation index were defined. The theoretical model to analyze the performance of permanent magnets was also established as above. Second, by controlling volume and rotational inertia to be the same, three types of permanent magnets were calculated. Finally, the optimization design process was proposed. Three preferable solutions were systematically compared and analyzed taking radially magnetized cylindrical permanent magnets as an example. Our work provides valuable insights into the design of mechanical antenna radiation sources.
Influence of the Spatial Distribution of Molecular Magnetic Moments on the Radiation Characteristics of Rotating Permanent Magnet Antennas
PIER Letters
Vol. 115, 63-70, 2024
download: 163
A Low RCS Design Under a Large Incident Angle for the Curved Surface Edge Considering Edge Effects
Guanya Li
In the context of the backscatter problem caused by edge diffraction on metallic curved surfaces, this study proposes a method to mitigate the scattering effect by loading different metasurface structures in four equally divided regions along the surface edge. Based on the design of the loaded metasurface on the curved surface, the interaction between the reflection field on the surface and the diffracted field is regulated by adjusting two key parameters: the reference phase (φ0) at the edge and the phase difference (φd) in adjacent regions. By controlling these parameters, reduction in the monostatic radar cross-section (RCS) can be achieved when the metasurfaces are loaded onto the curved surface. By controlling the reflection phase of a sandwich-like unit structure subjected to oblique incidence of electromagnetic waves, a metasurface that meets the requirements has been designed. Through a comparison and analysis of the near field and monostatic radar cross-section before and after loading the metasurface, the effectiveness of this design method is confirmed. This method is of great significance to control the electromagnetic scattering caused by edge diffraction.
A Low RCS Design under a Large Incident Angle for the Curved Surface Edge Considering Edge Effects
PIER Letters
Vol. 115, 57-62, 2024
download: 203
A Compact Multi-Band Monopole Antenna for 5G NR Coal Mine Applications
Yanhong Xu , Tingting Bai , Zhiwen Zhang , Anyi Wang , Can Cui and Jianqiang Hou
At present, 5G technology is gradually applied in coal mine applications. Under this circumstance, a microstrip patch antenna based on a multi-branch structure is firstly designed which can operate at the allocated 5G NR (2.51-2.68 GHz, 3.40-3.60 GHz and 4.80-4.90 GHz) for coal mine. Nevertheless, this antenna exhibits a large size, even at the lowest operating frequency (0.41λ×0.41λ at 2.51 GHz). To reduce the size of the antenna, the three branches are separately bent into C, S, and L shapes from left to right, and a size of 0.33λ×0.33λ at 2.51 GHz is realized, i.e., 35% size reduction is achieved. To further achieve a compact size, a new structure is designed. In particular, two inverted J-shaped branches and a rectangular branch acting as radiating portion are respectively arranged and optimized to cover the above three frequency bands where the rectangular branch is located between the two inverted J-shaped branches. To enhance the impedance matching characteristic of the antenna, a T-shaped structure is loaded on the other side of the substrate. The resultant size of this antenna is 0.20λ×0.16λ at 2.51 GHz, which is around 81% and 71% smaller than the first and second designed antennas. The measured results of the antennas are in good agreement with the simulated ones. Therefore, the third antenna is a good candidate for coal mine applications due to its relatively small size, low profile and easy integration with equipment.
A Compact Multi-band Monopole Antenna for 5G NR Coal Mine Applications
PIER Letters
Vol. 115, 47-55, 2024
download: 249
Frequency-Selective and Broadband Measurements of Radio Frequency Electromagnetic Field Levels in the University Campus
Doruntinё Berisha , Hëna Maloku Berzati , Jeta Dobruna , Zana Limani Fazliu and Mimoza Ibrani
Characterization of radio frequency electromagnetic field exposure levels is considered crucial for green and sustainable wireless-empowered campuses. To investigate the university campus electromagnetic characteristics, we conducted concurrent environment-oriented and human-centric measurement campaigns with broadband and frequency selective methodologies, respectively. The broadband results are derived after processing samples of 6-minute averages of measured electric and magnetic field values, taken at various university indoor and outdoor spots using broadband survey meter. Comparative analysis of broadband measurements shows that campus outdoor electric field levels in the sub 3 GHz band average around 1.67 V/m are at least twice higher than the ones recorded in indoor environments such as dormitories, labs, and classrooms. Students' exposure pattern in the 88 MHz-6 GHz range is derived after post-processing of more than 340 thousand electric field samples which were taken every 5 seconds at various campus environments using narrowband frequency selective measurement equipment. The comparison of cumulative distribution functions per wireless technology and environment shows that Wi-Fi is the main contributor to students' personal exposure levels in indoor environments and exceeds the 2G-5G mobile communication emitted electric fields in campus outdoor environments. The presented results can be used for exposure-aware heterogeneous network planning and optimization in university campuses or comparable environments.
Frequency-selective and Broadband Measurements of Radio Frequency Electromagnetic Field Levels in the University Campus
PIER Letters
Vol. 115, 39-46, 2024
download: 205
A Quad-Band High-Isolated MIMO Microstrip Antenna for Coal Mine Communication
Yanhong Xu , Peipei Dong , Anyi Wang , Jianqiang Hou and Shanshan Li
In this letter, a quad-band high-isolated MIMO microstrip antenna is designed for coal mine communications, which can operate at DCS1800, UMTS, WiMAX, WiFi, and 5G NR simultaneously. Firstly, the qual-band property is realized by designing a quaddent structure. In particular, three L-shaped branches (separately operating at 2.6 GHz, 3.5 GHz, and 4.8 GHz) are successively loaded on a monopole antenna (operating at 1.9 GHz). In the sequel, by symmetrically placing two quaddent structures with spacing of 0.19λ, a MIMO antenna is designed. At this time, the isolation level of the MIMO antenna can be as high as around 8 dB. To improve the performance of the MIMO antenna, an inverted cross-shaped branch is loaded on and two rectangular slots are etched off the ground successively between the two elements. In this way, an isolation level of over 20 dB can be achieved across the whole operating frequency bands. To verify the performance of the designed antenna, a prototype is fabricated and tested, and good agreement between the simulated and measured results indicates that the proposed antenna can completely cover DCS1800, UMTS, WiMAX, WiFi, and 5G NR (1.67~2.28 GHz, 2.39~2.79 GHz, 3.13~3.74 GHz and 4.69~5.34 GHz) for mining.
A Quad-band High-isolated MIMO Microstrip Antenna for Coal Mine Communication
PIER Letters
Vol. 115, 33-37, 2024
download: 177
LTCC-Packaged Branch-Line Coupler Using Capacitance Improved Capacitor for VHF-Band Applications
Shunjie Yu , Bo Zhou , Gang Shi and Shanwen Hu
A compact branch-line coupler is proposed with capacitance improved capacitor (CIC) using low-temperature co-fired ceramic (LTCC) packaged technology. The proposed CIC is constructed for higher capacitance without any size increment by further separated horizontal finger pads on VIC. The area of the coupler is only 10.3 × 9.4 × 1 mm3, which is equivalent to 0.0041 × 0.0035 × 0.0004λg3. The application frequency band covers maritime and aircraft navigation in the very high frequency (VHF)-band. The measured in-band S11, S21, S31 and S41 are better than -15, -4.1, -2.2 and -18 dB from 47 to 67 MHz, respectively. And the measured phase difference between the coupled and through ports is within 90±0.2°, which presents an excellent linear characteristic.
LTCC-packaged Branch-line Coupler Using Capacitance Improved Capacitor for VHF-band Applications
PIER Letters
Vol. 115, 27-32, 2024
download: 163
A Miniaturized Frequency Selective Surface for GSM Shielding by Utilizing a Spiral Handshake Structure
Xian-Jun Sheng , Chen Gu , Ning Liu , Hongwei Wang and Xiangyan Liu
This paper aims to design a compact frequency selective surface (FSS) for electromagnetic shielding in the 1.8 GHz band of GSM, ensuring that the stopband width covers the target frequency range in both simulations and actual measurements. The primary focus of this paper is to design a compact FSS with good miniaturization for real-world applications. The proposed FSS structure is a single-layer double-sided structure. The regression models reflecting the mapping relationship between the resonant frequency and the structural parameters are established to guide the design. An equivalent circuit model (ECM) is presented to clearly explain the working mechanism of the FSS. The unit size is only 0.038λ0, where λ0 is the wavelength of the resonant frequency in free space. In addition, the proposed FSS provides stable performance under oblique angles of incidence for both TE and TM polarizations. An FSS prototype has been manufactured for verification.
A Miniaturized Frequency Selective Surface for GSM Shielding by Utilizing a Spiral Handshake Structure
PIER Letters
Vol. 115, 19-25, 2024
download: 176
Wideband Capability in Embedded Stacked Rectangular Dielectric Resonator Antenna for X-Band Applications
Jihad Ben Yamoun and Noura Aknin
This paper introduces a novel design of an embedded stacked Rectangular Dielectric Resonator Antenna (RDRA). The antenna structure incorporates two distinct materials, namely PLA (Polylactic Acid) and Alumina, possessing dielectric constants of 3.45 and 9.9, respectively. A coaxial probe is employed to feed the antenna, enabling efficient signal transmission. The simulated results indicate the presence of two distinct resonance frequencies, which are 9.4 GHz and 10.6 GHz. Furthermore, the simulated antenna exhibits a maximum gain of 7.7 dB at 10.6 GHz, while demonstrating a wideband characteristic spanning approximately 22.7% of the frequency band between 8.75 GHz and 11 GHz on the measurement. The design and simulation of the RDRA are carried out using CST 2020 microwave studio, ensuring accurate and reliable results. The proposed antenna configuration is well suited for X-band applications such as radar and satellite systems.
Wideband Capability in Embedded Stacked Rectangular Dielectric Resonator Antenna for X-band Applications
PIER Letters
Vol. 115, 15-18, 2024
download: 138
Research on Multi-Rgion Compensation Plasma Device
Yutian Li , Yingying Wang , Zhanrong Zhou , Xiaofang Shen , Chao Ma , Yiming Chen and Guoqing Zhang
Conventional solid-state plasma devices encounter limitations in terms of the concentration and distribution uniformity of solid-state plasma, which adversely affects their microwave characteristics and overall antenna system performance. In this study, we propose a novel heterogeneous SPIN diode with multi-region compensation effects aimed at addressing this challenge. By incorporating SiGe regions within the intrinsic region of the device, we enhance the carrier injection ratio, effectively compensating for the rapid attenuation of solid-state plasma. As a result, a high-concentration and uniformly distributed solid-state plasma region is achieved within the SPIN diode, surpassing a concentration threshold of 1×1018 cm-3 within the intrinsic region. Through extensive simulations utilizing Sentaurus TCAD software, we demonstrate notable improvements in plasma concentration, distribution uniformity, and other key electrical parameters compared to traditional devices. The presented findings mark significant advancements in the realm of silicon-based plasma devices and hold promise for reconfigurable antenna systems.
Research on Multi-rgion Compensation Plasma Device
PIER Letters
Vol. 115, 9-14, 2024
download: 125
Rapid Estimation of Shielding Effectiveness in Chest and Abdomen Regions of Electromagnetic Shielding Clothing
Yi Yang , Miaomiao Kang and Xiuchen Wang
The shielding effectiveness (SE) of electromagnetic shielding (EMS) clothing is primarily achieved through experimental testing, but this method comes with drawbacks such as high cost, extended time, and imprecise testing outcomes. In order to quickly and cost-effectively obtain the protective performance of clothing, this article proposes a fast estimation method for the local SE of EMS clothing, which can quickly estimate the SE in the chest and abdomen regions through human body shape parameters. Firstly, an elliptical conical surface model is established for the chest and abdomen regions according to the shape of the human body. Following the principle of calculus, a local SE solution method based on this model is constructed. Additionally, a model correction coefficient that takes into account the impact of holes and seams is offered. Finally, a rapid estimation method is established for the SE of the chest and abdomen regions of the clothing. Experiments are ultimately designed to validate the model. In conclusion, the estimated values of the model are in agreement with the measured values, and it exhibits fast and efficient performance. This paper provides a new way to rapidly estimate the SE of EMS clothing in local areas, and plays an important role in promoting the design, evaluation and related detection of EMS clothing.
Rapid Estimation of Shielding Effectiveness in Chest and Abdomen Regions of Electromagnetic Shielding Clothing
PIER Letters
Vol. 115, 1-8, 2024
download: 146
Design of Radiation Protection Topology for Pulsed High Currents in Electromagnetic Launcher Based on Decision Variable Analysis
Heyang Wang , Jian Sun , Yuantao Cong , Mingjie Zhong and Binyu Zhu
Aiming to address the problem of radiation interference caused by pulse high current in the electromagnetic launcher's working process, this study presents a model for selecting materials for the protection of radiation sources and designing their topological structure. Initially, an analysis is conducted on the selection of materials and topology for the protective characteristics, considering factors such as protective effectiveness, production cost, structural rigidity, reliability, and mobility. Through shielding process, several factors influencing material selection are identified. Subsequently, weights and excitation functions are assigned to these factors to generate an applicability evaluation function of the protective materials, aligning with the test requirements. Next, three structures are defined for the test environment: inner shield, outer shield, and wrap-around shield, in accordance with the established protection topology. Using ANSYS, a three-dimensional simulation model is constructed, featuring a peak pulse current of 281.98 kA and an armature mass of 10 g. The shielding performance of materials with thicknesses of 3 mm, 5 mm, 7 mm, and 10 mm is analyzed. Simulation results demonstrate that the outer shielding structure and wrap-around shielding structure can achieve a magnetic induction strength of less than 0.5 T at approximately 6 mm thickness, validating the feasibility of the proposed model. This paper presents a method for addressing electromagnetic radiation protection from the electromagnetic launcher, ensuring the safety of personnel near the gas pedal and the stable operation of electronic components. The findings have significant implications for the future application of the system.
Design of Radiation Protection Topology for Pulsed High Currents in Electromagnetic Launcher based on Decision Variable Analysis