PIER M | PIER Journals

2023-01-30

PIER M

Vol. 115, 45-58, 2023

download: 7

A Miniaturized Ultra-Wideband MIMO Antenna Design with Dual-Band Notched Characteristics

Xuan Lu Shushu Linghu Furong Peng Ting Zhang

In this manuscript, a miniaturized Multi-Input Multi-Output (MIMO) antenna with dual-notch characteristics is designed for Ultra-Wideband (UWB) indoor positioning system. The proposed UWB MIMO antenna has a compact size of 35*35 mm² with four orthogonally placed antenna elements on the print circuit board (PCB) with FR4. Each radiating element utilizes the combination of a rectangle and an irregular pentagon, and etches two inverted L-shaped slits to generate two notches in WLAN (5.00 GHz-5.82 GHz) and X-band (7.11 GHz-8.20 GHz). On the grounding planes, the rectangle grounding units are modified into L-shaped branches, on which stepped open-circuit slots and right-angled triangle truncations are etched to broaden the impedance bandwidth. Furthermore, three equidistant rectangular decoupling slits are etched to improve the isolation. The measured results are in good agreement with the simulated ones, which shows an impedance bandwidth of 116.68% (2.96-11.25 GHz) with isolation better than 17 dB. The antenna also has excellent characteristics of good radiation characteristics, total active reflection coefficient (TARC), diversity gain (DG>9.99), low envelope correlation coefficient (ECC<0.005) and channel capacity loss (CCL<0.4 bits/sec/Hz), which can be used in portable UWB-MIMO indoor positioning system.

A Miniaturized Ultra-wideband MIMO Antenna Design with Dual-band Notched Characteristics

2023-01-23

PIER M

Vol. 115, 35-44, 2023

doi:10.2528/PIERM22120220

download: 1

A Novel Decoupling Technique for Single-Layered Closely-Spaced Patch Antenna Arrays

Sai Radavaram Maria Pour

A new technique to reduce the mutual coupling between closely-spaced, single-layered patch antenna elements is presented. The proposed design comprises an integrated novel decoupling structure to generate an out-of-phase decoupling signal to effectively lower the coupling between the elements. In addition, coplanar L-probes and interdigital filter shaped slits on the ground plane are incorporated to further improve the isolation. The realized isolation level is about 28 dB at the frequency of operation. This is a significant achievement for a single-layered low-profile structure, wherein the center-to-center element spacing is only around 0.25λ₀, and more importantly, no shorting vias are used.

A Novel Decoupling Technique for Single-layered Closely-spaced Patch Antenna Arrays

2023-01-07

PIER M

Vol. 115, 21-34, 2023

doi:10.2528/PIERM22100201

download: 11

A Gain Enhanced Dual-Band Low SAR AMC-Based MIMO Antenna for WBAN and WLAN Applications

Chengzhu Du Ling-Ru Pei Jie Zhang Cheng-Xin Shi

On the basis of artificial magnetic conductors (AMCs), a dual-band MIMO antenna is suggested. For WBAN and WLAN applications, the frequency ranges supported by this antenna system are 2.36-2.51 GHz and 5.03-6.12 GHz. The proposed dual-band MIMO antenna is made up of two vertically positioned dipole antenna elements. A simple double circle-based AMC array is suggested to decrease radiation exposure to people while increasing forward gain. The antenna and the 3×3 AMC array are both printed on an FR4 substrate. The presented antenna with the AMC structure is manufactured and measured in order to confirm the simulated results in terms of S-parameters, radiation patterns, gain, and diversity parameters. According to the measurements, the suggested antenna exhibits peak gains of 3.34 dBi and 7.48 dBi at 2.45 GHz and 5.8 GHz, respectively. The SAR value of body tissue can be reduced by around 99% while the front-to-back ratio (FBR) is noticeably enhanced. The proposed AMC-supported MIMO antenna is applicable for WBAN and WLAN applications based on the above good performances.

A Gain Enhanced Dual-band Low SAR AMC-based MIMO Antenna for WBAN and WLAN Applications

2023-01-07

PIER M

Vol. 115, 11-20, 2023

doi:10.2528/PIERM22092006

download: 8

Statistics of Two Indicators for Multilook Scattering Signals from Multilayered Structures with Slightly Rough Interfaces

Richard Dusséaux Saddek Afifi

Within the framework of the first-order small perturbation method, we derive the statistics of the layered rough surface index and the normalized difference polarization index for three-dimensional layered structure with slightly rough interfaces illuminated by a monochromatic plane wave and for multilook returns. We establish closed-form expressions for the probability density function and the cumulative distribution function. The first- and second-order moments are given by relation recurrences. We validate from Monte Carlo simulations the obtained theoretical formulas.

Statistics of Two Indicators for Multilook Scattering Signals from Multilayered Structures with Slightly Rough Interfaces

2022-12-27

PIER M

Vol. 115, 1-10, 2023

doi:10.2528/PIERM22110509

download: 62

Effect of the Temperature and the Geometrical Parameters on the Modal Properties of Circular Photonic Crystal Fiber

Mohammed Chamse Eddine Ouadah Mohammed Debbal Hicham Chikh-Bled Mouweffeq Bouregaa

This paper presents a proposal for a high birefringμeμnce photonic crystal fiber (C-PCF) with a doped liquid into two first ring holes, which is analyzed by the finite element method. It is demonstrated that the proposed fiber has a birefringence value of about 2.643 × 10^-2 at wavelength λ = 1.55 µm and temperature T = 25˚C. Also, a high chromatic dispersion of -272 ps/nm/km, an effective area of 1.693 µm², and a confinement loss of 0.058 dB/m for the x-polarization method were obtained at the same wavelength and temperature. The temperature influence on the modal properties has also been studied. We will demonstrate through the result that the fiber we propose can be used in both sensing and chromatic dispersion applications such as flattened dispersion fibers.