PIER Letters | PIER Journals

2024-02-13

PIER Letters

Vol. 117, 97-101, 2024

doi:10.2528/PIERL23120804

download: 235

Varactor Loaded Phase Shifter with Frequency-Adaptive Control Circuit

Waleed Alomar , Abdullah Alburadi , Meshaal Alyahya and Hussein Shaman

This paper introduces a novel RF phase shifter design that operates at constant phase shift over operation frequency range. The proposed phase shifter utilizes the conventional reflective-type phase shifter which is inherently frequency-dependent. The introduced reflective-type phase shifter design is integrated with an adaptive control circuit that varies the required DC voltage as a function of the frequency. Thus, the phase shift will be relatively constant throughout the frequency of operation compared to the conventional frequency-dependent reflective-type phase shifter. The phase shifter is designed to operate at 90˚ and is shown to maintain that phase shift with around 15˚ compared to the conventional design where the phase shift varies by more than 60˚ at the same bandwidth. The proposed design, including the adaptive controlled circuit, is fabricated, and the measured data agree with simulations.

Varactor Loaded Phase Shifter with Frequency-adaptive Control Circuit

2024-02-10

PIER Letters

Vol. 117, 89-96, 2024

doi:10.2528/PIERL23111804

download: 480

A Compact Multiband Hybrid Rectangular DRA for Wireless Applications

Lavuri Nageswara Rao , Govardhani Immadi , Madhavareddy Venkata Narayana , Ambati Navya , Aovuthu Sree Madhuri and Kolasani Rajkamal

A new tri band rectangular DRA is simulated and tested for wireless communication applications like ISM, Wi-Max, and WLAN. The dielectric resonator antenna structure is excited by a 50 Ω transmission line. The rectangular DRA with concentric square rings is designed to acquire the operation of triple-bands. The parametric analysis of the rectangular DRA has been carried on HFSS tool. The rectangular DRA exhibits triple-band characteristics at 2.16-2.57 GHz, 3.35-4.45 GHz, and 5.35-5.95 GHz, with a fractional bandwidth of 17.3%, 28.1%, and 10.6%, respectively. The implemented concentric square rings are imposed on FR4-substrate material to emphasize the antenna parameters and to minimize the size. The designed DRA has a compact size, good radiation properties and optimal operational bandwidth. To validate the antenna, it is fabricated, and the fabricated DRA results match well with the simulated ones. The antenna is well suitable for wireless communication applications. The fabricated rectangular DRA is measured by using MS2037C Anritsu-Combinational Analyzer.

A Compact Multiband Hybrid Rectangular DRA for Wireless Applications

2024-02-10

PIER Letters

Vol. 117, 83-88, 2024

doi:10.2528/PIERL23112601

download: 447

A Compact Coplanar Waveguide Spoof Surface Plasmon Polariton with Enhanced Field Confinements

Chao Pang and Lin Li

In this article, a novel transmission line (TL) based on coplanar waveguide (CPW) spoof surface plasmon polariton (SSPP) with flipper structures is proposed to improve field confinement. An equivalent circuit (E.C) is developed to analyze the proposed SSPP. The E.C analyses reveals that the proposed unit exhibits flexibly controllable dispersion features and improved field confinements owing to the introduction of the flipper structures. Finally, the proposed SSPP TL is designed, fabricated, and tested to validate the design principles. The experiment results illustrate the theoretical analyses and validate that the proposed SSPP TL exhibits ultra-compact size occupation and enhanced field confinement.

A Compact Coplanar Waveguide Spoof Surface Plasmon Polariton with Enhanced Field Confinements

2024-02-08

PIER Letters

Vol. 117, 75-81, 2024

doi:10.2528/PIERL23112403

download: 298

Wideband Multi-Linear Polarization Reconfigurable Antenna for Wireless Communication System

Kaisheng Yang , Na Kou and Shixing Yu

This letter presents a wideband multi-linear polarization reconfigurable antenna, which has the ability to switch among four linear polarizations at rotation angle of 45°, namely 0°, 45°, 90° and -45°. Its main structure consists of three layers of substrates and a reflective cavity. Four pairs of crossed bow-tie dipoles are used as the primary radiators, and the polarization switching is realized by controlling the ON/OFF states of four pairs of PIN diodes between feeding source and the dipoles. In addition, circular ring and reflective cavity structures are used for enhancing the operating bandwidth, stabilizing the radiation patterns and increasing the gain. Finally, the simulation and measurement results both demonstrate that the antenna exhibits an overlapped impedance bandwidth of 42.6% (2.4 GHz-3.7 GHz) for all polarization states, and it remains a steady radiation pattern within the operating bandwidth. With these features, the design can be used in wireless communication systems in the 5G sub-6 GHz band.

Wideband Multi-linear Polarization Reconfigurable Antenna for Wireless Communication System

2024-02-07

PIER Letters

Vol. 117, 69-73, 2024

doi:10.2528/PIERL23122201

download: 275

Unconventional Method for Antenna Array Synthesizing Based on Ascending Clustered Rings

Jafar Ramadhan Mohammed

Recently, clustered antenna arrays have been proved as an efficient method in implementing the large planar arrays for massive MIMO wireless communications in 5G and beyond applications. However, obtaining optimum clustering configurations needs a high computational time, and it does not guarantee a total clustering coverage of the whole array aperture. In this paper, a new and unconventional array pattern synthesis method based on ascending/descending clustered subarray rings is presented. The method is equally applicable to the rectangular and circular planar arrays where they are first divided into multiple square or circular clustered rings starting from the largest ring at the array perimeter up to the last ring (the smallest one) at the array center. Then the amplitude distributions of these clustered rings are optimized to obtain the desired radiation characteristics subject to the user-defined constraint mask. Implementation of the proposed array at the clustered level instead of the conventional element level offers many advantages such as simplified feeding network, efficient taper efficiency, low sidelobe level, and high directivity. Simulation results show the effectiveness of the proposed method for both square and circular planar array layouts.

Unconventional Method for Antenna Array Synthesizing Based on Ascending Clustered Rings

2024-02-04

PIER Letters

Vol. 117, 61-67, 2024

doi:10.2528/PIERL23110101

download: 239

A Triband Slot Antenna Loaded with Asymmetric Split Ring Resonator for Wireless Applications

Vinaya Kumar Sugganapalya Rajanna , Thimmegowda Venkatesh , Puneeth Kumar Tharehalli Rajanna and Mudukavvanavar Shambulinga

For applications involving triple bands, a small slot structure loaded with an asymmetric split ring resonator (ASRR) is suggested in this article. The slot mode, which is agitated with the help of a microstrip line feed, produces the first band. 2.24 GHz resonance frequency is the intended operating band. The sand third frequency bands are achieved by loading ASRR on the slot. The slot produces axial magnetic field required to excite the ASRR. The asymmetry introduced in the conventional SRR produces dual resonances. The ASRR gives the resonant frequencies at 2.97 GHz and 3.66 GHz. The frequency bands of the slot and ASRR can be independently tuned. The proposed geometry is verified experimentally, and it is in good agreement with the simulated one. The impedance bandwidth of all three resonant bands measured from experiment are 14.25%, 1.78%, 8.37%. The peak gains of 3.1 dBi, 2.18 dBi, and 3.29 dBi are obtained at resonant points, respectively. The designed antenna is compact and well suits for wireless application like WLAN, GPS, and LTE48/TD3600.

A Triband Slot Antenna Loaded with Asymmetric Split Ring Resonator for Wireless Applications

2024-01-31

PIER Letters

Vol. 117, 55-59, 2024

doi:10.2528/PIERL23022704

download: 380

Curvature-Based Feature Representation for Ship Detection in SAR Image

Zhenyu Chen and Meng Yang

This article aims to exploit Ricci tensor with certain geometric properties which are used for feature representation and ship detection in synthetic aperture radar (SAR) image. The proposed method is composed of the following key points. Firstly, Riemannian metrics on the Gamma manifold are constructed based on the family of Gamma density functions. Secondly, direct calculation gives the Ricci tensor of Gamma manifold, where the curvature tensor resorts to the torsion-free affine connection. Thirdly, a general scheme for Zermelo navigation problem on the Riemannian manifold is addressed, and the solution of the navigation problem is proposed. Fourthly, feature representation problems are formulated as certain forms of Finsler metric of Randers type, indicating a joint framework for extracting low-dimensional features with closed-form solutions. Comprehensive experiments on real SAR image data sets demonstrate the effectiveness of the proposed method against compared state-of-the-art detection approaches.

Curvature-based Feature Representation for Ship Detection in SAR Image

2024-01-30

PIER Letters

Vol. 117, 47-54, 2024

doi:10.2528/PIERL23121505

download: 252

A Broadband SIW Cavity-Backed Circular Arc-Shaped Slot Antenna for Millimeter-Wave Applications

Mingming Gao , Chunli Liu , Jingchang Nan and Hongliang Niu

A broadband circular arc-shaped slot antenna is proposed in this paper which operates from 25.1 GHz to 31.5 GHz. The antenna is based on a substrate-integrated waveguide (SIW) and fed through a grounded coplanar waveguide (GCPW). A circular arc-shaped slot is presented instead of a conventional narrow rectangular slot to extend bandwidth performance. The slot antenna generates six closely resonant frequencies by exciting high-order modes, which help get a broadband response. Antenna's prototype is fabricated using the standard Printed Circuit Board (PCB) process. The results of its measurement show that the antenna achieves an impedance bandwidth of 22.6% at 28 GHz and a peak gain of 11.5 dBi. The efficiency in the operating bandwidth is more than 85%. The antenna shows the merits of low-profile, high-gain, and broadband characteristics, which are very suitable for mm-wave wireless communication systems.

A Broadband SIW Cavity-backed Circular Arc-shaped Slot Antenna for Millimeter-wave Applications

2024-01-29

PIER Letters

Vol. 117, 41-46, 2024

doi:10.2528/PIERL23113004

download: 319

Compact Single Notch UWB Bandpass Filter with Metamaterial and SIW Technique

Senathipathi Udhayanan and Krishnan Shambavi

A design of compact planar SIW filter with notch band characteristics is proposed. Double split square complementary split ring resonators are used to realize the ultra-wide band (UWB) characteristics. Proposed UWB filter contributes a passband from 2.9 GHz to 10.3 GHz with minimum insertion loss 0.7 dB at 3.7 GHz and maximum of 1.84 dB at 7 GHz. By employing complementary split ring resonator in the ground plane, a narrow band characteristic is obtained to reject the undesired wireless local area network (WLAN) signals. The notch band frequency ranges from 5 GHz to 5.7 GHz with insertion loss of 14 dB at center frequency. The 3 dB fractional bandwidth in the notch band is 12.9%. The variation of group delay less than 0.5 ns in the passband range. Overall size of the proposed filter is 0.35λ_g × 1.06λ_g. Because of these salient features, the proposed filter can be used for space applications.

Compact Single Notch UWB Bandpass Filter with Metamaterial and SIW Technique

2024-01-28

PIER Letters

Vol. 117, 33-40, 2024

doi:10.2528/PIERL23103001

download: 408

Sensorless Control of Permanent Magnet-Assisted Synchronous Reluctance Motor Based on Adaptive Sliding Mode Observer

Aide Xu , Xinyu Li , Shimai Hu and Xin Liu

To solve the issue of chattering that occurs during the estimation of the rotor position in the permanent magnet-assisted synchronous reluctance motor using the conventional sliding mode observer (SMO), the saturation function is used in this paper instead of the original sign function to reduce its jittering effect; to solve the problem of phase delay caused by the low-pass filter (LPF), the adaptive law is implemented as a substitute for the LPF. This allows for a smoother back electromotive force and eliminates the need for position compensation caused by phase delay; finally, the phase-locked-loop (PLL) technique is used to extract more accurate rotor position information. A 3 kW permanent magnet-assisted synchronous reluctance motor is taken as the control object, and a simulation model of the control system is established. The results show that the improved saturation function adaptive SMO has higher level of accuracy in estimating rotor position information than the conventional SMO.

Sensorless Control of Permanent Magnet-assisted Synchronous Reluctance Motor Based on Adaptive Sliding Mode Observer

2024-01-28

PIER Letters

Vol. 117, 27-32, 2024

doi:10.2528/PIERL23113002

download: 417

Wafer Level 3D-Stacked Integration Technology with Coplanar Hot via MMIC for mm -Wave Low-Profile Applications

Xiaobo Zhu , Yujin Zhou and Jun Zhou

Wafer-level three-dimensional stacked integration technology is demonstrated in this paper, employing three gallium arsenide (GaAs) monolithic integrated circuits (MMICs) and gold (Au) bumps, and specifically designed for high-density and low-profile applications operating at millimeter-wave frequencies. A ground coplanar waveguide to ground coplanar waveguide (GCPW to GCPW) hot via interconnect has been developed to facilitate vertical transitions within a multi-stacked electromagnetic (EM) environment. Electrical connection between the upper and lower layers is achieved through 70 μm-height Au bumps. Compared to 2.5D packaging, this innovative structure exhibits an increased integration capability of more than three times within the same area, with a thickness of 0.451 mm. Ultra-wideband transmission between RF chips is achieved within a compact area of 0.16 square millimeters, enabling extremely short-distance interconnect for system-in-package configurations. Appropriate utilization of ground metal within the package ensures strict electromagnetic field confinement, preventing interference from adjacent circuits. The designed transitions were fabricated and characterized. The measured result has an insertion loss of less than 0.65 dB and return loss of better than 20 dB up to 40 GHz for a back-to-back structure. This integration technology can further enhance integration capability, reduce transmission loss, and improve electromagnetic isolation. The presented approach holds significant potential for applications requiring high-density integration and reliable performance in the millimeter-wave regime.

2024-01-24

PIER Letters

Vol. 117, 21-26, 2024

doi:10.2528/PIERL23101802

download: 258

Low Phase Noise, High Output Power and Compact Microwave Planar Oscillator for C-Band Applications

Hanae Elftouh , Moustapha El Bakkali , Aicha Mchbal , Soukaina Sekkal and Naima Amar Touhami

In this paper, a novel microwave oscillator is developed at frequencies of 5.7 and 7.5 GHz through the application of Negative Resistance and Harmonic Balance theory. The design process involves leveraging the Agilent Advance Design System (ADS) tool, ensuring exceptional electromagnetic (EM) performance. The utilization of microstrip circuit elements enhances the overall performance of the oscillator structure. Following optimization and co-simulation of nonlinear models for the compact Planar Microwave Oscillator (62x38 mm²), highly satisfactory results are obtained. Quantitatively, the measured output powers at 5.7 and 7.5 GHz are determined to be 9.5 dBm and 7.05 dBm, respectively. These power levels are particularly relevant for C band applications spanning 4 to 8 GHz, including areas such as satellite communication, radar, and wireless networks.

Low Phase Noise, High Output Power and Compact Microwave Planar Oscillator for C-band Applications

2024-01-23

PIER Letters

Vol. 117, 13-19, 2024

doi:10.2528/PIERL23062903

download: 359

Exploring Interferences Arising in the Construction of GPR Responses from an Object Buried Between Two Rough Surfaces by GPILE Method

Marc Songolo , Nicolas Pinel and Christophe Bourlier

In this paper, we explore interferences arising in the electromagnetic scattering by an object buried inside a layer with two rough interfaces by using the GPILE method. We show that there are two categories of interferences in the echoes that make up GPILE: the interferences that are present whatever the chosen scenario and those that come from the geometry of the problem (distance between the three scatterers). In this last category, we can cite for example the interferences which come from the position of the object, more precisely from its depth, because an object closer to one of the surfaces would produce echoes which arrive almost at the same time as those of the nearby interface.

Exploring Interferences Arising in the Construction of GPR Responses from an Object Buried between Two Rough Surfaces by GPILE Method

2024-01-21

PIER Letters

Vol. 117, 9-12, 2024

doi:10.2528/PIERL23111205

download: 270

A Generalized Solution for h -Polarized Scattering from Shallow Cavities with an Arbitrary Profile

Mehdi Bozorgi

In this paper, a generalized manner is developed for the problem of the scattering of H-polarized electromagnetic waves from a shallow cavity with an arbitrary profile. Considering a proper auxiliary border and employing the region-matching technique, some close-form expressions are derived to compute the fields inside and outside the cavity. Next, we apply this approach to two cavities with different shapes and verify it by the Method of Moments (MoM).

2024-01-19

PIER Letters

Vol. 117, 1-7, 2024

doi:10.2528/PIERL23110901

download: 354

Detection of Pathogens Using PET Based Microwave Assisted Irradiation to Extend Bread Shelf-Life

Govindarajan Venkat Babu , Arvind Kumar , Kumareson Anish Pon Yamini , Kamatchi Govindaraj Sujanth Narayan and Rajesh Kumar Dhandap

Prolonging the shelf life of bread through cost-effective methods becomes imperative in times of a pandemic when numerous countries are grappling with extended lockdowns. This study explores the application of microwave food processing to identify pathogens by inducing rapid, selective heating within the material. A critical issue in microwave food processing is the uneven distribution of heat, creating cold spots that amplify pathogen growth, thereby increasing the risk of foodborne illnesses such as acute poisoning, diarrhea, fever, abdominal pain, and, in severe instances, even death. In this context, we propose a method for pathogen detection using polyethylene terephthalate (PET), which involves subjecting the bread to high thermal irradiation. To achieve this, a low-profile inset-fed PET-based microstrip patch antenna operating at 4 GHz is employed to detect pathogens by analyzing variations in S-parameters. The suggested PET antenna introduces a flexible approach to pathogen detection, especially at the edges and corners, owing to the conformable choice of substrate.