PIER M | PIER Journals

2025-02-20

PIER M

Vol. 132, 49-59, 2025

download: 7

Research on the Simulation Method of the Security Check Scene Based on Passive Millimeter-Wave Imaging

Chuan Yin, Siyi Zhang and Pengpeng Xu

Current research on passive millimeter wave (PMMW) human security imaging mainly focuses on system optimization and image processing algorithms, with limited attention on simulation studies. This paper addresses this gap by developing a PMMW imaging simulation for human security screening. The study proposes a Multi-layer Brightness Temperature Tracing Method (MBTTM) to accurately calculate brightness temperature values across various scattering directions. The paper proposes a simulation model for microrough surfaces based on the rough characteristics of human skin in security check scenarios. It also presents a PMMW brightness simulation model for detecting hidden dangerous goods in hierarchical media. The model incorporates diffuse ray tracking and accounts for transmission phenomena when rays interact with penetrable surfaces. Finally, both simulation and experimental validation are conducted for human security scenes.Experimental results demonstrate the effectiveness of the proposed method in detecting concealed objects, with a detailed analysis of the impact of surface roughness, ray spacing, and concealment depth on imaging quality.

Research on the Simulation Method of the Security Check Scene Based on Passive Millimeter-wave Imaging

2025-02-08

PIER M

Vol. 132, 39-48, 2025

doi:10.2528/PIERM24112304

download: 147

Conception and Realization of a Wideband Directional Dual-Beam Phased MIMO Array Antenna with Hybrid Coupler for ISM Band Utilizations

Abdelaaziz El Ansari, Shobhit Kisan Khandare, Najiba El Amrani El Idrissi, Abdelhak Bendali, Sudipta Das, Fatima Younis, Hala Kamal Abduljaleel and Ahmed Jamal Abdullah Al-Gburi

This work addresses a wideband dual-beam 1x4 phased MIMO array antenna with a hybrid coupler for Industrial, Scientific and Medical (ISM) bands applications at 2.4-2.5 GHz. We engineered, refined, and reduced the fundamental component utilizing the novel concept of an advanced curved quarter-wave impedance adapter, achieving a 50% reduction in size relative to comparable designs documented in the literature. The fundamental component operates at 2.45 GHz, including a narrow bandwidth of 26 MHz and a maximum gain of 7.21 dB. Subsequently, a lossless magic-T power splitter is employed to feed two identical miniaturized elements resulting in a compact 1 × 2 array antenna with miniaturized size and enhanced performance. The results obtained show that the miniaturized 1 × 2 array antenna resonate at 2.45 GHz with a narrow impedance bandwidth of 52 MHz, peak gain of 9.41 dB and a peak directivity of 9.48 dB at 2.45 GHz. To broaden the narrow bandwidth and to enhance gain, directivity and radiation coverage area, a 3 dB hybrid coupler is used to feed two identical miniaturized 1 × 2 array antennas resulting a wideband directional dual-beam MIMO phased 1 × 4 array antenna. The proposed dual-beam array antenna prototype has been designed and fabricated on a substrate Rogers RT/duroid 5880 with the following parameters: relative permittivity ε_r = 2.2, dielectric loss tangent of 0.0009, and total size of 240 × 136 × 1.56 mm³. The simulation results are corroborated by experiments that verified the proposed dual-beam MIMO array antenna which exhibits a high gain of 11.2 dB, effective adaptation, an expanded bandwidth of 1.22 GHz, in addition to its MIMO capability and the dual beams oriented at ±30˚, achieved through switching between the two input feed ports of the hybrid coupler.

Conception and Realization of a Wideband Directional Dual-beam Phased MIMO Array Antenna with Hybrid Coupler for ISM Band Utilizations

2025-02-02

PIER M

Vol. 132, 31-38, 2025

doi:10.2528/PIERM24121004

download: 104

General Array Imaging Network for Near-Field Synthetic Aperture Interferometric Radiometer

Chenggong Zhang, Jianfei Chen, Jiahao Yu, Yujie Ruan, Sheng Zhang, Shujin Zhu and Leilei Liu

Millimeter wave synthetic aperture interferometric radiometer (SAIR) can achieve high-resolution imaging without a large physical aperture antenna and has strong application advantages in the fields of earth remote sensing, astronomical observation, and meteorological monitoring. In order to adapt to various payload platforms and detection needs, the existing SAIR array structures are diverse, but the existing imaging methods are difficult to effectively deal with various arrays and achieve stable high-precision imaging inversion. Thus, this paper proposes a general multi-channel fusion imaging network to achieve SAIR imaging inversion of any array structure. First, with the help of the sensor matrix deduction subnet, a high-precision imaging sensor matrix is deduced according to the position of each array element of the SAIR system, and then high-precision image reconstruction is achieved with the help of the multi-channel fusion imaging subnet. The simulation results show that the network has good adaptability and can achieve high-precision imaging inversion of different SAIR array structures.

General Array Imaging Network for Near-field Synthetic Aperture Interferometric Radiometer

2025-01-31

PIER M

Vol. 132, 21-30, 2025

doi:10.2528/PIERM24112101

download: 165

Ultra-Miniaturized Spiral Antenna for Loop Recorder Implantable Device

Marwah M. Hassooni, Jabir S. Aziz and Ashwaq Q. Hameed

The miniaturization of implantable antenna is one of the significant requirements, especially for those devices implanted under the skin, as it reduces prominent appearance and invasiveness. In this paper, we design, simulate, and implement a spiral resonator-based microstrip antenna utilizing the ISM band (2.4-2.48 GHz). A small size, light weight, and flat type are required for under-skin implantation. The proposed antenna dimensions were optimized for a miniaturized volume of (3 × 2.5 × 0.12) mm³, representing the smallest size for under-skin biomedical applications. This miniaturization is achieved using a spiral-shaped radiator and creating slots in the ground layer. In-vivo measurement parameters, including reflection coefficient, are measured on the suggested antenna, showing a gain of -19.9 dBi and a bandwidth of 90 MHz. Specific Absorption Rate (SAR) is evaluated at 316 W/kg, confirming that the proposed antenna meets the necessary human-use safety criteria.

Ultra-miniaturized Spiral Antenna for Loop Recorder Implantable Device

2025-01-27

PIER M

Vol. 132, 11-19, 2025

doi:10.2528/PIERM24090903

download: 151

A Low-Profile EBG Based Corrugated 5G Antenna Design for WLAN Communication

Hema Raut, Saffrine Kingsly, Sangeetha Subbaraj and Rajeshwari Malekar

The paper introduces a corrugated antenna structure suitable for 5G WLAN application and operates at a frequency of 5.52 GHz. Further, a periodic structure made up of square unit cells is combined with the antenna design, and improvement in gain and impedance bandwidth is observed. The antenna gain without periodic structure is 3.48 dB whereas with periodic structure it is noted as 4.09 dB. The antenna dimensions are 16 mm × 16 mm × 3 mm. Also, the measured bandwidth of the antenna structure without periodic structure is observed to be 210 MHz, and that with periodic structure is 310 MHz.

2025-01-26

PIER M

Vol. 132, 1-10, 2025

doi:10.2528/PIERM24121306

download: 141

A Spiral Cavity Backed 4 X 4 MIMO SIW Antenna at Ku Band for Radio Telescopes

Suryansh Saxena, Nidhi Tewari and Shweta Srivastava

A compact spiral cavity backed substrate integrated waveguide (SIW) multiple input multiple output (MIMO) antenna is presented in this paper. The edge-shaped spiral on top of the SIW cavity acts as a dipole antenna. The dual spiral arms are excited from their symmetrical connecting center. The single antenna element in MIMO is rotated such that unit cells are orthogonal to each other forming a compact 2 × 2 and 4 × 4 MIMO SIW antenna. The proposed design shows a wide bandwidth of 930 MHz (13.74 GHz to 14.67 GHz) and 67.68% impedance bandwidth. The overall size of proposed MIMO SIW antenna is 0.9λ_o × 0.9λ_o × 0.024λ_o, where λ_o is the operating wavelength. A return loss of 18.4 dB at 14.17 GHz is achieved. The series of metal pins (in plus shape) at the center of 4 × 4 MIMO improves the isolation to 19.6 dB at resonant frequency. A pattern diversity in broadside direction is achieved by the top spiral arms and its complementary spiral arms at the bottom. The beamwidth of the proposed antenna is 90˚ varying from -45 deg to +45 deg, useful for reliable signal transmission and reception. Thus, the proposed antenna is a symmetrical compact design working at Ku band suitable for radio telescope application.