PIER C | PIER Journals

2024-12-25

PIER C

Vol. 151, 113-121, 2025

download: 24

A Compact, Conformal DRA with Integrated Feed for Low-Profile Applications

Pramod Kumar Gupta, Garima Tiwari, Manshree Mishra and Biswajeet Mukherjee

A novel compact low-profile Conformal Dielectric Resonator Antenna (CDRA) for wideband applications is proposed. By employing a specially designed dielectric resonator in conjunction with an inverted-trapezoidal patch for feeding, an extensive Impedance Bandwidth (IB) of around 51.5% is realized. The resonant frequencies of 6GHz and 7.5GHz correspond to the observation of the TE21δ mode and the second higher-order TE23δ mode, respectively. Moreover, a realized peak gain of 7.2dBi is attained at 7.4GHz. The proposed DRA offers a wide IB with more than 90% radiation efficiency throughout the bandwidth. Additionally, a good alignment is observed between the measured and simulated results. The proposed DRA is compact and low-profile of 0.1λg, where λg represents the wavelength at the lower cut-off frequency. A CDRA with a conformal feed is an innovative design tailored for wireless communication systems operating within the frequency range from 5.2GHz to 8.8GHz. This antenna configuration is specifically engineered to exhibit conformal properties, enabling it for applications such as the exteriors of vehicles, aircraft, or other non-planar structures.

2024-12-25

PIER C

Vol. 151, 101-112, 2025

doi:10.2528/PIERC24110702

download: 14

A Frog-Shaped UWB MIMO Antenna Design for 5G

Shanhua Yao, Tianchu Yang, Xiaorong Qiu and Xiang Li

In this paper, a frog-shaped ultra-wideband (UWB) multiple-input multiple-output (MIMO) antenna is proposed for 5G applications in the n77, n78, n79, and 6 GHz bands with a compact antenna structure of 31×55×1.5 mm³. The designed antenna consists of two frog-shaped monopole antennas and a floor from which part has been removed, and the operating bandwidths range from 3.05 to 13.38 GHz, which meets the design criteria for UWB. The T-shaped floor with two T-shaped slots impedes the flow of coupling currents and improves the isolation of the antenna. This results in an isolation of less than -17 dB over the entire operating bandwidth and less than -20 dB in the 5G band. In addition, the envelope correlation coefficient (ECC) is less than 0.007, the diversity gain (DG) more than 9.96, the total active reflection coefficient (TARC) less than -30 dB, and the channel capacity loss (CCL) less than 0.34 bit/s/Hz. The measured and simulated results agree with each other, demonstrating their potential application in 5G communication systems.

A Frog-shaped UWB MIMO Antenna Design for 5G

2024-12-22

PIER C

Vol. 151, 91-100, 2025

doi:10.2528/PIERC24110502

download: 31

Gap-Coupled Design of Elliptical Shape Microstrip Antennas for Wideband Circular Polarized Response

Amit A. Deshmukh, Heet Mistry and Venkata A. P. Chavali

A gap-coupled design of elliptical shape microstrip antennas for wideband circularly polarized response is proposed. The wideband nature of the response is attributed to the gap-coupling between the orthogonal resonant modes on the fed and parasitic elliptical shape patches. With the total substrate thickness of 0.11λ_cAR, the gap-coupled antenna offers the reflection coefficient bandwidth of 784 MHz (55.68%) that includes circularly polarized bandwidth for axial ratio ≤3 dB of 542 MHz (35.82%). The antenna offers a broadside radiation pattern across the bandwidth, with a peak gain larger than 10 dBi. A design methodology to realize a similar gap-coupled antenna in a different frequency range is presented that yields similar wideband results. With the obtained antenna characteristics, proposed designs will find applications in GPS L and GSM 900 frequency bands. An experimental verification for the obtained simulated results is carried out, which provides a close agreement.

Gap-coupled Design of Elliptical Shape Microstrip Antennas for Wideband Circular Polarized Response

2024-12-21

PIER C

Vol. 151, 81-89, 2025

doi:10.2528/PIERC24101405

download: 48

Fracture Detection in Bone Tissue Models Using h -Slot Shaped Transceiver Resonators

Wongani Moyo, Ahmed Allam, Asano Tanemasa and Adel Bedair Abdel-Rahman

In this paper, a novel H-slot resonator of size 30 mm x 20 mm x 1.56 mm for fracture detection, backed with a perfect electric conductor (PEC), designed at 2.54 GHz is presented, and its performance is evaluated. Concurrently, an equivalent circuit model of the resonator is developed, and its performance coherently agrees with the CST model. The design is tested using a hybrid tissue phantom based on a second-order Debye dielectric tissue model. The detection of fractures of several thicknesses with a minimum width of 2 mm and a maximum of 10 mm was compared. Overall, the proposed design improves the detection of fractured regions in a bone with a 2 mm crack width as the smallest detectable crack size.

Fracture Detection in Bone Tissue Models Using H-slot Shaped Transceiver Resonators

2024-12-19

PIER C

Vol. 151, 73-79, 2025

doi:10.2528/PIERC24102501

download: 33

Tumor Detection and Imaging through Body Scanning Using TMSA Operating in MBAN Band

Satheesh Rao

In this article, body scanning and imaging using a triangular microstrip antenna (MSA) with microstrip line feeding is presented. The resonant frequency of this antenna is 2.383 GHz having 20 dB bandwidth 3 MHz. The results comply with the 2.36 to 2.39 GHz band that the Federal Communication Commission (FCC) has designated for medical related applications. This antenna is used in scanning the human body model to detect the presence of tumor. The scan results are used to generate a 2-D color contour plot, which shows the location of tumor. Parametric analysis is carried out to fix the slot dimension to get optimum antenna performance. After successful simulation, the antenna structure is fabricated, and testing is carried out using Power Network Analyzer.

Tumor Detection and Imaging through Body Scanning Using TMSA Operating in MBAN Band

2024-12-14

PIER C

Vol. 151, 65-71, 2025

doi:10.2528/PIERC24092403

download: 133

A Compact Monopole Slotted Patch-Antenna for UWB Applications

Yousif Mohsin Hasan

This paper presents a compact single-feed, rectangular slotted-patched antenna (SPA) for UWB applications. The proposed design adds a triangular part of the tail of the rectangular patch, cuts the edge of the patch, etches a rectangular slot in the ground plane, and then tunes the basic parameters of the design to achieve the UWB passband. The proposed antenna including slots on the patch for compact functionality is readily identifiable. The bandwidth and realized gain of the UWB antenna can be extremely improved to show the ability of a slot loading technique. The new conception of the rectangular patch antenna is considered. A feed mechanism using an inset patch feedline is implemented and analyzed. The parameters of the antenna are demonstrated, and the antenna is fabricated with an inexpensive FR4 substrate and validated experimentally. The antenna occupies frequency band (2.56-12) GHz. Making slots in the modified patch results in a significant gain improvement of 4.8 dBi as well as extending the UWB passband. The measured values of the reflection coefficient, VSWR, realized gain, and power pattern are in good agreement with the simulated results.

A Compact Monopole Slotted Patch-antenna for UWB Applications

2024-12-13

PIER C

Vol. 151, 57-64, 2025

doi:10.2528/PIERC24110501

download: 63

A Bandpass Filter Using Substrate Integrated Waveguide Cavity for Nonlinear Junction Detection Applications

Boyan Zhang, Minquan Li, Guocui Zhu, Yongkang Yuan, Chen Li, Shuang Xiao and Xin Qu

A band-pass filter utilizing a dual-mode Substrate Integrated Waveguide (SIW) cavity, enhanced by a novel Defected Ground Structure (DGS) is proposed in this paper. The SIW cavity operates in TE₁₁₀ and TE₁₂₀ modes, and the electric field of TE₁₁₀ is modified by introducing a series of metallized disturbance holes at the center of SIW cavity to increase the resonant frequency of TE₁₁₀ mode to that of TE₁₂₀ mode, thereby forming a passband with two transmission poles. A DGS that combines a dumbbell structure with a Complementary Split Ring Resonator (CSRR) is employed on the ground plane of the filter to improve the stopband rejection and suppress the parasitic passband. EM simulation and measurement results suggest that the center frequency of the filter is 4.8 GHz. It achieves a 3 dB-bandwidth of 300 MHz, with its insertion loss in the passband up to 0.5 dB and return loss greater than 20 dB. The designed DGS introduces a transmission zero near 7.2 GHz to suppress the parasitic passband and enhance the selectivity of the filter, while maintaining the original insertion loss and return loss within the passband. Its overall layout is simple and innovative. The designed filter is specifically engineered for application in the receiver of Nonlinear Junction Detection (NLJD) systems, aiming to suppress interference signals and allow only the second harmonic to pass through, which holds certain practical significance in RF engineering.

A Bandpass Filter Using Substrate Integrated Waveguide Cavity for Nonlinear Junction Detection Applications

2024-12-12

PIER C

Vol. 151, 45-56, 2025

doi:10.2528/PIERC24103101

download: 37

Design and Experimental Study of Dual-Band Left-Handed Filters for Sub-6G Applications

Zhonghui Li, Chen Li and Minquan Li

This paper presents a dual-band microstrip filter with left-handed characteristics, featuring high selectivity and miniaturization. The design achieves negative permittivity and permeability by integrating H-shaped complementary split-ring resonators (CSRRs) within a substrate integrated waveguide (SIW). To enhance out-of-band rejection performance, a defected ground structure (DGS) is introduced. By applying the Half Mode SIW (HMSIW) principle, the equivalent magnetic walls of the SIW are cut, resulting in a 50% size reduction. Dual-frequency characteristics are realized using a symmetrical H-shaped CSRR, with the filter operating in the Sub-6G frequency band. Experimental results demonstrate that the filter exhibits good selectivity and low insertion loss at 3.5 GHz and 4.8 GHz. Tuning of the second frequency band is achieved by adjusting the coupling distance between the CSRR and metal via. This work has significant application potential in the fields of wireless communication and RF technology. The study provides theoretical support and technical insights for the design of future compact multi-band filters.

Design and Experimental Study of Dual-band Left-handed Filters for Sub-6G Applications

2024-12-11

PIER C

Vol. 151, 33-43, 2025

doi:10.2528/PIERC24102102

download: 46

Design and Analysis of Linear Primary Permanent Magnet Vernier Machines with Different Winding Configurations

Zhijian Ling, Qi Zhang and Meimei Xu

This paper investigates the effects of winding configurations on force density and fault tolerance in linear primary permanent magnet vernier (LPPMV) machines. Firstly, the LPPMV machines with integral slot distributed windings (ISDWs) and fractional slot concentrated windings (FSCWs) are discussed. Due to the high modulation ratio of ISDW machine, it has the potential to achieve higher thrust force capabilities. Then, the operation principle of the LPPMV machines is analyzed from the perspective of air-gap magnetic modulation. Furthermore, it should be noted that the winding configurations of ISDW machine has larger spans, resulting in insufficient fault-tolerance. To solve this limitation, a new modular ISDW LPPMV machine was proposed and optimized. In the modular ISDW LPPMV machine, a 3×3-phase winding configuration is employed. It is demonstrated that modular ISDW LPPMV machines exhibit superior characteristics in both thrust density and fault tolerance. Finally, the experiments are carried out in a linear test bench, verifying the theoretical analysis.

Design and Analysis of Linear Primary Permanent Magnet Vernier Machines with Different Winding Configurations

2024-12-11

PIER C

Vol. 151, 25-31, 2025

doi:10.2528/PIERC24101302

download: 57

A Novel Proof-of-Concept AI-Driven Approach for Advanced Electromagnetic Imaging

Ali Ghaffarpour, Tahereh Vasei, Mahindra Ganesh, Reza K. Amineh and Maryam Ravan

This paper introduces an artificial intelligence (AI) methodology designed to enhance the output of two-dimensional (2D) electromagnetic imaging systems, specifically tailored for the imaging of conductive objects utilizing inductive sensors. The core of our imaging system comprises a commercial data acquisition board, alongside custom-made multilayer planar coils developed by conventional printed circuit board technology. By leveraging recent advances in AI and machine learning, our approach significantly improves the resolution and clarity of electromagnetic images. The paper uses a multi-layer perceptron (MLP) classifier to process the raw electromagnetic data captured by the imaging system. These algorithms are trained to recognize patterns and anomalies in electromagnetic field data, which are often indicative of conductive objects. The enhanced imaging capability is demonstrated through a series of experiments that compare the AI-enhanced outputs with the ground truth.

A Novel Proof-of-Concept AI-Driven Approach for Advanced Electromagnetic Imaging

2024-12-11

PIER C

Vol. 151, 13-24, 2025

doi:10.2528/PIERC24102605

download: 53

Application of Attention Mechanism-Enhanced BiLSTM -CNN in Power Amplifier Behavioral Modeling and Predistortion

Jingchang Nan, Shize Liu and Jiadong Yu

Power amplifiers in wireless communication systems can introduce nonlinear distortion, degrade signal transmission quality, and increase power consumption. The paper presents a BiLSTM-CNN-based model for modelling power amplifier behaviour to address this issue. The model uses BiLSTM layers to capture temporal information from the signal data and incorporates a multi-head attention mechanism to focus on different temporal features. Additionally, convolutional layers process global features and reduce model parameters through weight sharing. Using this model, a digital pre-distortion (DPD) model is proposed to linearise the power amplifier through an indirect learning approach. The results show that the BiLSTM-CNN model achieves a normalised mean square error (NMSE) of -40.3dB, and the DPD model enhances the adjacent channel power ratio (ACPR) of the communication system by 18dB, demonstrating the model's feasibility. Comparative analysis with other network models indicates that BiLSTM-CNN outperforms traditional methods of fitting performance and convergence speed, showcasing its superiority.

Application of Attention Mechanism-enhanced BiLSTM-CNN in Power Amplifier Behavioral Modeling and Predistortion

2024-12-08

PIER C

Vol. 151, 1-12, 2025

doi:10.2528/PIERC24101603

download: 56

AI-Tuned Metantenna Antenna for Fifth Generation & Beyond Communication Applications

Bikash Ranjan Behera and Harikkrishna Paik

For the purpose of fifth-generation and beyond communication applications, broadband circularly polarized (CP) & high gain AI-tuned metantenna operating in the 5 GHz band is presented in this article. So, an linearly polarized (LP) printed monopole antenna is being taken into consideration in the initial stage. To initiate CP from LP, a metallic strip that functions as a dynamic switching mechanism is utilized to short one of the parasitic conducting strips (PCS) with partial ground plane. The objective is to enhance the impedance (IBW) and axial bandwidths (ARBWs) as well as the antenna gain in order to make it a suitable candidate for ambient RF energy harvesting/wireless energy harvesting application. To achieve this, AI-tuned metasurface is placed below the monopole radiator at a height of 0.33λ_o. With a measured 49.84% IBW, 22.36% ARBW, CP gain > 8 dBic, antenna efficiency > 70%, fabricated on an FR-4 substrate with 1.3λ_o x 0.9λ_o x 0.02λ_o, it is suitable for the technological deployments in a current wireless technology, assuring resilience in networks. To meet the ever-increasing requirements of the current scenario, wireless communication landscape is on a paradigm shift. This transformation is brought by the utilization of metasurfaces offering customized, effective, and typical control of electromagnetic waves keeping with the desired frequency conditions.