Archive

25 posts

Filters: category: RF Engineering Clear

Comparative Analysis of Beamforming Techniques and Beam Management in 5G Communication Systems

Research RF Safe Research Library Jan 1, 2025

This engineering paper reviews and classifies beamforming techniques in 5G New Radio and examines beam management procedures at Layer 1 and Layer 2. It analyzes the spectral spectrogram of Synchronization Signal Blocks (SSBs) to illustrate how configuration parameters influence spectral occupancy and…

Machine Learning Approach for Ground-Level Estimation of Electromagnetic Radiation in the Near Field of 5G Base Stations

Research RF Safe Research Library Jan 1, 2025

This paper presents a machine-learning method to estimate ground-level electromagnetic radiation (electric field strength) in the near field of 5G base stations, using multiple technical and environmental input parameters. The authors report experimental performance with a mean absolute percentage error of about…

A Deep Learning Framework for Evaluating the Over-the-Air Performance of the Antenna in Mobile Terminals.

Research RF Safe Research Library Jan 1, 2024

This engineering study presents RTEEMF-PhoneAnts, a convolutional neural network framework to predict mobile phone antenna metrics (EIRP, TRP, and SAR) from near-field EMF distributions. Using a dataset of 7000 mobile phone models, the authors report statistical validation for predicted SAR/TRP and a validation…

Advanced Radio Frequency Applicators for Thermal Magnetic Resonance Theranostics of Brain Tumors.

Research RF Safe Research Library Jan 1, 2023

This engineering/simulation study evaluates RF applicator array designs for Thermal Magnetic Resonance (ThermalMR), which combines MRI with RF hyperthermia for brain tumor theranostics. Using EMF and temperature simulations at 7.0 T, 9.4 T, and 10.5 T, hybrid loop+SGBT dipole arrays are reported to provide superior…

Wideband Self-Grounded Bow-Tie Antenna for Thermal MR.

Research RF Safe Research Library Jan 1, 2020

This engineering study designed and tested a compact wideband self-grounded bow-tie RF antenna module for a whole-body 7.0 T MRI system, aiming to enable 1H/19F MRI, MR thermometry, and broadband RF thermal intervention. The authors report validated B1 efficiency measurements and phantom-based heating experiments…

Miniaturized Battery-Free Wireless Systems for Wearable Pulse Oximetry.

Research RF Safe Research Library Jan 1, 2017

This engineering study describes miniaturized, flexible, battery-free wearable pulse oximetry systems that use near-field communication (NFC) for wireless operation. The devices capture and transmit photoplethysmograms to derive blood oxygenation, heart rate, and heart rate variability. The abstract reports…

In-to-out body path loss for wireless radio frequency capsule endoscopy in a human body.

Research RF Safe Research Library Jan 1, 2016

This engineering study uses a 3D electromagnetic solver to simulate in-to-out body RF path loss for a wireless capsule endoscopy link. The capsule antenna is tuned for the 402 MHz MICS band while accounting for human body properties. The authors examine how capsule misalignment, rotation, and the human body model…

Stable radio frequency dissemination by simple hybrid frequency modulation scheme.

Research RF Safe Research Library Jan 1, 2014

This engineering paper describes a fiber-based method for stable radio-frequency dissemination using a hybrid frequency modulation approach. Two RF components are transmitted simultaneously using a single laser diode, with one component used for phase fluctuation detection and the other providing a compensated stable…

Wireless Communication of Intraoral Devices and Its Optimal Frequency Selection.

Research RF Safe Research Library Jan 1, 2014

This engineering study assesses optimal RF frequencies for wireless communication with intraoral electronic devices using an intraoral tongue drive system as an example. It compares 27 MHz, 433.9 MHz, and 2.48 GHz based on path loss, radiation patterns, and bit error rate tests, with adaptive impedance matching…

Effect of sputtering power on structural and optical properties of radio frequency-sputtered In2S3 thin films.

Research RF Safe Research Library Jan 1, 2014

This engineering/materials study examined how RF magnetron sputtering power affects the structural and optical properties of In2S3 thin films intended as a CdS buffer substitute in CIGS solar cells. Films deposited at 60–120 W were characterized using XRD, AFM, EDS, and UV-visible spectrophotometry. The films were…

Linear and stable photonic radio frequency phase shifter based on a dual-parallel Mach-Zehnder modulator using a two-drive scheme.

Research RF Safe Research Library Jan 1, 2013

This paper presents a theoretical and experimental demonstration of a photonic RF phase shifter based on a dual-parallel Mach-Zehnder modulator using a two-drive scheme. The approach aims to mitigate residual optical carrier effects and avoid a lowest-frequency limitation from an optical filter by driving the…

A wireless magnetoresistive sensing system for an intraoral tongue-computer interface.

Research RF Safe Research Library Jan 1, 2012

This engineering paper presents an intraoral version of the Tongue Drive System (iTDS) built into a dental retainer. It uses four 3-axis magnetoresistive sensors to detect tongue motion and transmits digitized data wirelessly via a dual-band 27/432 MHz transmitter, with configuration updates via a 13.56 MHz inductive…

A mm-sized wirelessly powered and remotely controlled locomotive implant.

Research RF Safe Research Library Jan 1, 2012

This engineering paper describes a mm-scale implantable device that is wirelessly powered and remotely controlled to locomote in a fluid medium. The prototype is reported to receive 500 µW from a 2 W, 1.86 GHz RF power signal at 5 cm and to support 2.5–25 Mbps data rates using asynchronous PWM on the carrier. The…

Nanocrystalline graphite films nucleation by the radio frequency bias pretreatment.

Research RF Safe Research Library Jan 1, 2011

This paper describes an engineering method for nucleating nanocrystalline carbon films on monocrystalline silicon using a combination of microwave and radio frequency plasma-assisted chemical vapor deposition. The approach is demonstrated via deposition of nanocrystalline diamond after a seeding step and growth of…

Fuzzy mobile-robot positioning in intelligent spaces using wireless sensor networks.

Research RF Safe Research Library Jan 1, 2011

This engineering study develops and experimentally evaluates a fuzzy-logic method for locating mobile robots in an intelligent space using wireless sensor networks. Localization relies on inter-node range measurements estimated from RF signal strength attenuation, which the authors describe as noisy and unreliable.…

Interoperation of an UHF RFID reader and a TCP/IP device via wired and wireless links.

Research RF Safe Research Library Jan 1, 2011

This engineering paper describes a system implementation for interoperation between a 915 MHz UHF RFID reader and a TCP/IP gateway device. The architecture uses wired communication between the TCP/IP device and RFID reader, and wireless ZigBee (IEEE 802.15.4) links to an end-device/coordinator. Web-based tests are…

A radiofrequency coil to facilitate B₁⁺ shimming and parallel imaging acceleration in three dimensions at 7 T.

Research RF Safe Research Library Jan 1, 2011

This paper reports the development of a 15-channel transmit-receive RF coil for 7 T human brain MRI, using a hybrid decoupling approach to support element placement along three axes. The design is presented as enabling B1+ shimming and parallel imaging acceleration in three dimensions, with reported isolation and…

Reduction of implant RF heating through modification of transmit coil electric field.

Research RF Safe Research Library Jan 1, 2011

This engineering study describes modifying MRI RF transmit coil electric-field distributions to create electric field-free zones without substantially changing transmit sensitivity. Phantom experiments are reported to show reduced implant heating when a zero electric-field plane is aligned with the implant location.…

Extraordinary magnetic field enhancement with metallic nanowire: role of surface impedance in Babinet's principle for sub-skin-depth regime.

Research RF Safe Research Library Jan 1, 2009

This paper proposes metallic nanowires as complementary structures to metallic nanogaps for enhancing magnetic fields. It reports magnetic field enhancement up to a factor of 300 and presents a surface-impedance-based analytic theory that is numerically confirmed. The authors also report that, in the sub-skin-depth…

Silicon-on-insulator-based radio frequency single-electron transistors operating at temperatures above 4.2 K.

Research RF Safe Research Library Jan 1, 2008

This engineering study demonstrates a silicon-on-insulator (SOI) radio-frequency single-electron transistor (RF-SET) operating at temperatures above 4.2 K. The device was optimized to address high resistance in SOI SETs and showed stable transport characteristics after repeated thermal cycling. RF-SET operation was…

Influence of mashed potato dielectric properties and circulating water electric conductivity on radio frequency heating at 27 MHz.

Research RF Safe Research Library Jan 1, 2008

This engineering study used experiments, computer simulations, and simplified analytical calculations to examine how mashed potato dielectric properties and circulating water electrical conductivity affect RF heating at 27 MHz. The authors report that higher circulating water conductivity and higher salt content in…

[Microstrip antenna design and system research of radio frequency identification temperature sensor].

Research RF Safe Research Library Jan 1, 2008

This engineering paper introduces an RFID sensor network concept integrating RFID with wireless sensor networks and emphasizes the role of antennas. It discusses coil, dipole, and microstrip antennas and reports designing a microstrip antenna for a wireless temperature monitoring and control system. Measurements are…

Single access point localisation for wearable wireless sensors.

Research RF Safe Research Library Jan 1, 2008

This engineering conference paper describes a single access point method for localizing a subject using RF signals from wearable wireless sensors. The approach combines RSSI and LQI measurements from one basestation and applies filtering. The abstract reports that accuracy can approach that of multi-basestation…

Position-independent chemical quantitation with passive 13.56-MHz radio frequency identification (RFID) sensors.

Research RF Safe Research Library Jan 1, 2008

This engineering study evaluates whether passive 13.56-MHz RFID-based chemical sensors can quantify analytes reliably despite repositioning errors between the sensor and pickup coil. Using simultaneous measurement of multiple complex-impedance parameters and multivariate statistical analysis, the authors report…

Development of a patch antenna array RF coil for ultra-high field MRI.

Research RF Safe Research Library Jan 1, 2007

This engineering study describes development of a patch antenna array coil (PAAC) intended to address short RF wavelength challenges in ultra-high-field (≥7T) MRI. A prototype PAAC for 7T proton imaging was used to image a monkey brain. The authors report that the imaging demonstrated the coil's utility for…

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