Radio Frequency Detection Research Articles

Analysis of mobile phone radiation effect on human body using specific absorption rate

The use of mobile phones is rising everyday both in civic and rustic areas in Bangladesh. Every mobile phone disperses electromagnetic energy. This radiation or electromagnetic wave can penetrate into the human body. Specific absorption rate and change in temperature are the vital parameter to find the dominant effects assess on the human body. This paper explores the radiation impact of mobile phones. A mathematical equation is used to evaluate the local specific absorption rate and change in temperature at Skin, Fat, Bone, Brain, Eye, Muscle tissues at the frequency of 800MHz, 900 MHz, 1800 MHz, 2100 MHz, 2.5GHz, 2.6GHz, 3.4GHz, 3.5GHz, and 3.6GHz. The calculations are performed at different distances and exposure times of mobile phone. A simple radio frequency detection circuit has been designed to find the radiated power of different frequency. The highest specific absorption rate is calculated for skin, brain, eye tissue. Child tissue absorption rate is higher than the adult. When the radiated power of mobile phone is high the specific absorption rate for different tissue cross the safety limit. This paper also recommends the ways to diminish the effects of SAR. It is suggested that these methods will decrease the health risks. This work will be very helpful to understand the bad effect of using mobile phones and the way of reducing this effect.

Retraction: "Improving signal-to-noise ratio of magnetic tunnel junction based radio frequency detector via spin-torque ferromagnetic resonance" [Rev. Sci. Instrum. 93, 053904 (2022)

Retraction: "Improving signal-to-noise ratio of magnetic tunnel junction based radio frequency detector via spin-torque ferromagnetic resonance" [Rev. Sci. Instrum. 93, 053904 (2022)

Parametrically enhanced interactions and nonreciprocal bath dynamics in a photon-pressure Kerr amplifier.

Photon-pressure coupling between two superconducting circuits is a promising platform for investigating radiation-pressure coupling in distinct parameter regimes and for the development of radio-frequency (RF) quantum photonics and quantum-limited RF sensing. Here, we implement photon-pressure coupling between two superconducting circuits, one of which can be operated as a parametric amplifier. We demonstrate a Kerr-based enhancement of the photon-pressure single-photon coupling rate and an increase of the cooperativity by one order of magnitude in the amplifier regime. In addition, we observe that the intracavity amplification reduces the measurement imprecision of RF signal detection. Last, we demonstrate that RF mode sideband cooling is unexpectedly not limited to the effective amplifier mode temperature arising from quantum noise amplification, which we interpret in the context of nonreciprocal heat transfer between the two circuits. Our results demonstrate how Kerr amplification can be used as resource for enhanced photon-pressure systems and Kerr cavity optomechanics.

Risk Reduction Strategy to Decrease Incidence of Retained Surgical Items.

Retained surgical items (RSIs) are rare but serious events associated with significant morbidity and costs. We assessed the effectiveness of radiofrequency (RF) detection technology and Team Strategies and Tools to Enhance Performance and Patient Safety (TeamSTEPPS) in reducing the incidence of RSIs. All RSIs reported to the New York Patient Occurrence Reporting and Tracking System at five large urban teaching hospitals from 2007 to 2017 were analyzed. In 2012, TeamSTEPPS training was provided to all perioperative staff at each site, and use of RF detection became required in all procedures. The incidence of events before and after the interventions were compared using odds ratios. A total of 997,237 operative procedures were analyzed. After the interventions, the incidence of RSIs decreased from 11.66 to 5.80 events per 100,000 operations (odds ratio [OR] [95% CI] = 0.50 [0.32 to 0.78]). The frequency of RSIs involving RF-detectable items decreased from 5.21 to 1.35 events per 100,000 operations (OR [95% CI] = 0.26 [0.11 to 0.60]). The difference in RSIs involving non-RF-detectable surgical items was not statistically significant. The incidence of RSIs was significantly lower during the time period after implementing RF detection technology and after TeamSTEPPS training, primarily driven by a decrease in retained RF-detectable items. RF detection technology may be worth pursuing for hospitals looking to decrease RSI frequency. The benefit of TeamSTEPPS training alone may not result in a reduction of RSIs.

Broadly tunable and ultra-highly selective detection of radio frequency signals enabled by a silicon photonic chip.

Precise and agile detection of radio frequency (RF) signals over an ultra-wide frequency range is a key functionality in modern communication, radar, and surveillance systems, as well as for radio astronomy and laboratory testing. However, current microwave solutions are inadequate for achieving the needed high performance in a chip-scale format, with the desired reduced cost, size, weight, and power. Photonics-based technologies have been identified as a potential solution but the need to compensate for the inherent noise of the involved laser sources have prevented on-chip realization of wideband RF signal detection systems. Here, we report an approach for ultra-wide range, highly-accurate detection of RF signals using a conceptually novel feed-forward laser's noise cancelling architecture integrated on chip. The technique is applied to realization of an RF scanning receiver as well as a complete radar transceiver integrated on a CMOS-compatible silicon-photonics chip, offering an unprecedented selectivity > 80 dB, spectral resolution < 1 kHz, and tunability in the full 0.5-35 GHz range. The reported work represents a significant step towards the development of integrated system-on-chip platforms for signal detection, analysis and processing in cognitive communication and radar network applications.

Improving signal-to-noise ratio of magnetic tunnel junction based radio frequency detector via spin-torque ferromagnetic resonance.

This article focuses on the spin-torque ferromagnetic resonance (STFMR) technique, which was developed and optimized to investigate spin-transfer effects in magnetic tunnel junctions (MTJ) and spin Hall effect phenomena in ferromagnet/non-magnetic heavy metal bilayer systems. The devices for STFMR are typically fabricated with co-planar waveguides with contact pads for applying radio frequency or direct current, Irf(Idc). The device under investigation was a CoFeB/MgO/CoFeB based MTJ with a resistance-area product of 1.5 Ω (μm)2 having a circular cross section with a diameter of 180nm and tunneling magneto-resistance in the range of 60%-80%. The development of the STFMR setup and its optimization for achieving higher signal-to-noise ratio (SNR) is discussed using two modulation schemes, namely, radio-frequency modulation and field modulation (FM). The FM-STFMR method reduces frequency-dependent noise and offers a higher SNR of 30 dB compared to other modulation schemes in the literature. In addition, a vector network analyzer based STFMR technique is developed, which provides a simple and fast means for characterizing MTJ devices. Furthermore, to calculate the exact power reaching the MTJ, impedance mismatch is calculated using the de-embedding method. The magnitude of in-plane torkance and out-of-plane torkance with dc bias is measured, and the results are found to be consistent with the results of STFMR techniques. The results show that the magnitude of out-of-plane torkance is substantially smaller than that of in-plane torkance in MTJ.

Low-power RF signal detection with wideband range based on an optically injected optoelectronic oscillator.

A novel method to detect a low-power radio-frequency (RF) signal with ultra-wide frequency range based on an optically injected optoelectronic oscillator (OEO) is proposed and experimentally demonstrated. The optical injection to a distributed feedback (DFB) laser has the advantages of amplifying one sideband of the modulated optical signal selectively and a wide tunable frequency range. The detection upper range that reaches up to 26 GHz and can be improved theoretically. To the best of the authors' knowledge, this is the widest detection range based on an OEO. At the same time, the detection characteristics are good. The sensitivity of the system is -92 dBm and the maximum gain is 12.18 dB at 15.047 GHz. Considering the real application of the detection system, the properties such as dynamic range and performance for detecting a modulated RF signal are also investigated.

Hybrid Statistical and Numerical Analysis in Structural Optimization of Silicon-Based RF Detector in 5G Network

In this study, a hybrid statistical analysis (Taguchi method supported by analysis of variance (ANOVA) and regression analysis) and numerical analysis (utilizing a Silvaco device simulator) was implemented to optimize the structural parameters of silicon-on-insulator (SOI)-based self-switching diodes (SSDs) to achieve a high responsivity value as a radio frequency (RF) detector. Statistical calculation was applied to study the relationship between the control factors and the output performance of an RF detector in terms of the peak curvature coefficient value and its corresponding bias voltage. Subsequently, a series of numerical simulations were performed based on Taguchi’s experimental design. The optimization results indicated an optimized curvature coefficient and voltage peak of 26.4260 V−1 and 0.05 V, respectively. The alternating current transient analysis from 3 to 10 GHz showed the highest mean current at 5 GHz and a cut-off frequency of approximately 6.50 GHz, indicating a prominent ability to function as an RF detector at 5G related frequencies.

Carbon based electronic technology in post-Moore era: progress, applications and challenges

In the past 60 years, silicon-based semiconductor technology has triggered off the profound change of our information society, but it is also gradually approaching to the physical limit and engineering limit as well. Thus, the global semiconductor industry has entered into the post-Moore era. Carbon nanotube has many excellent electronic properties such as high mobility and ultra-thin body, so it has become a hopeful candidate for the new semiconductor material in the post-Moore era. After more than 20 years of development, carbon based electronic technology has made fundamental breakthroughs in many basic problems such as material preparation, Ohmic metal-semiconductor contact and gate engineering. In principle, there is no insurmountable obstacle in its industrialization process now. Therefore, in this paper the intrinsic advantages of carbon based electronic technology in the post-Moore era is introduced, the basic problems, progress and optimization direction of carbon based electronic technology are summarized, the application prospects in the fields of digital circuits, radio frequency electronics, sensing and detection, three-dimensional integration and chips for special applications are presented. Finally, the comprehensive challenges to the industrialization of carbon based electronic technology are analyzed, and its future development is also prospected.

Implementation of Rfid in Inventoy Management

Radio frequency detection has been one of the most developed and anticipated technologies in recent years. RFID is an automated framework for identification that uses RFID tags or navigation systems for remote storage and retrieval of data. RFID is perhaps the most exponentially evolved supply chain management technology. They are also used to integrate different processes that are part of daily operations and to optimize transport of goods across the production process. RFID facilitates real-time tracking of production, inventory prices and demand. On the other hand, the RFID solution is actually costly, unstandardized; manufacturers who undertake sequential projects are less in number and are dissatisfied with privacy concerns. This article explores the benefit and drawbacks of these labels in inventory management.

Development of the ion cyclotron emission diagnostic for the W7-X stellarator.

An ion cyclotron emission (ICE) diagnostic is prepared for installation into the W7-X stellarator, with the aim to be operated in the 2022 experimental campaign. The design is based on the successful ICE diagnostic on the ASDEX Upgrade tokamak. The new diagnostic consists of four B-dot probes, mounted about 72° toroidally away (one module) from the neutral beam injector, with an unobstructed plasma view. Two of the B-dot probes are oriented parallel to the local magnetic field, aimed to detect fast magnetosonic waves. The remaining two probes are oriented poloidally, with the aim to detect slow waves. The radio frequency (RF) signals picked up by the probes are transferred via 50 Ω vacuum-compatible coaxial cables to RF detectors. Narrow band notch filters are used to protect the detectors from possible RF waves launched by the W7-X antenna. The signal will be sampled with a four-channel fast analog-to-digital converter with 14 bit depth and 1 GSample/s sampling rate. The diagnostic's phase-frequency characteristic is properly measured in order to allow measuring the wave vectors of the picked up waves.

Recognition of UAV Video Signal Using RF Fingerprints in the Presence of WiFi Interference

This paper investigates the problem of unmanned aerial vehicle (UAV) recognition in the presence of WiFi interference using passive radio frequency (RF) detection. The proposed method relies on machine learning based RF recognition and considers the scenario in the bandwidth of the video signal (VS) and WiFi are identical. Our machine learning strategy involves extracting 31 features from the WiFi signal and the UAV VS, which are then input to the classifier. Among the 31 features, 30 are statistical in the time and frequency domain, while the remaining one involves the effective subcarrier feature. We evaluate four different machine learning (ML) classifier variants and demonstrate through simulation and experiments that the proposed method can accurately recognize UAV VS in the presence of WiFi interference. We also improve the feature-vector compactness and reduce the 31-feature vector to a 6-feature vector composed of the most significant features and demonstrate that the recognition performance of random forest method (RandF) classifier is not compromised. The most appealing performance for the 6-feature vector case is attained by the RandF, managing a recognition rate of 100% in the indoor experiment and 96.26% in the 2 km outdoor experiment. The recognition rate of the four ML classifiers is larger than 95.52% in the 2 km outdoor experiment, which is better than other UAV detection methods such as radar, acoustic and video.

Long-Term Stability Test on On-Wafer Measurement System in Frequency Ranges up to 325 GHz

This article reports the investigation results of long-term stability tests on on-wafer measurement systems in frequency ranges up to 325 GHz conducted by the NMIJ-AIST. The radio frequency (RF) probe coordinates in the $X$ -, $Y$ -, and $Z$ -directions, and the tilt angle is automatically adjusted by performing RF signal detection. Calibrations and verification processes were repeated for over a year. The novelty of the study is that it optimizes measurement procedures for the test, demonstrates a long-term stability test, and compares the evaluated long-term stability to the effects of probe model, absorber, and calibration method. The standard deviation of the measured reflection coefficient ranged between −32 to −70 dB in magnitude, and 0°–10° in phase. The standard deviation of the measured transmission coefficient ranged from −43 to −80 dB and from 0.2°–2.7° in phase. The refined procedures contributed to improve the measurement reproducibility compared to the previous report. Furthermore, the effects of the chuck material and the calibration method were larger than long-term stability.

2019 IEEE AP-S Student Design Contest - Team KnowAntenna [Education Corner

In this article, an affordable system to demonstrate some antenna parameters is described. It consists of a transmitter (Tx) based on a voltage-controlled oscillator (VCO), a receiver (Rx) implemented with radio-frequency (RF) detectors, and a rotary mechanical arrangement based on a stepper motor. A microcontroller (?C) performs the rotation, acquires data, and manages a set of peripherals. The measurements can be observed in real time and sent to a PC. The setup is easy to operate, making it a convenient tool for demonstrations in high schools to attract students to telecommunications.

Recent Developments in Near Field Communication: A Study

Near field communication, development in radio frequency detection has put its foot in today’s life of individuals through sophisticated mobile phones. NFC technology has become very popular due to its transparent and simple integration with a number of applications such as health care, consumer electronics, public transport payment methods, etc. A few new approaches have been attempted to make NFC progressively competent in routine day-to-day applications. This paper discusses the latest development in the use of NFC’s in a few implementations and the potential outcomes of the hustle-free implementation of these applications. A systematic analysis of recent research deployment in different areas of use has been clarified and explored.

Meandered low profile multiband antenna for wireless communication applications

The compact slotted antenna having offset feed radiating in the multi-frequency bands is proposed. The antenna geometry comprises of a vertical and horizontally coupled slotted structure at the top with a complete ground plane at the bottom to achieve the proposed application bands. The patch is patterned on the FR4 substrate having a dielectric constant of 4.4 and loss tangent of 0.008. The antenna has an overall dimension of 0.18λ × 0.15λ mm2 (f = 1.52 GHz) with offset fed which is optimized to achieve 50 Ω impedance matching. The proposed compact antenna resonates in pentaband frequency bands which includes 1.52–1.60 GHz for GPS (ISM band in India), 2.97–3.02 GHz for Radio frequency identification and detection, mobile communication, logistics, manufacturing, transportation and healthcare, 3.73–3.84 GHz for Amateur Fixed Mobile except aeronautical mobile (R), 4.42–4.52 GHz for radio communications, TransferJet USB Adapter (Toshiba Corporation), and 4.83–4.96 GHz for Aviation Private Land Mobile applications. The proposed antenna has demonstrated a decent gain ranging from 1.07 to 3.92 dBi having omnidirectional and bidirectional radiation patterns, hence, making it suitable for various wireless applications.

Dynamic characteristics of PdCoO2/β-Ga2O3 Schottky junctions

A high-frequency diode is an essential component in electrical circuits providing the current rectification function for AC/DC converters, radio frequency detectors, and automotive inverters. Schottky barrier diodes based on wide-bandgap semiconductors are promising for the high-frequency applications owing to short reverse recovery time that minimizes the energy dissipation during the switching. In this study, we report dynamic characteristics of Schottky junctions composed of a layered oxide metal PdCoO2 and an n-type β-Ga2O3 substrate. Rectifying current–voltage characteristics with reasonably small hysteresis were demonstrated up to a high frequency of 3 MHz in the PdCoO2/β-Ga2O3 Schottky junctions. For the on-state to off-state switching with the current ramp rate of approximately −2 × 1010 A/scm2, the reverse recovery time was as short as 11 ns. The short reverse recovery time was constantly obtained in the operation temperature range of 25–350 °C, showing low-loss switching properties of the PdCoO2/β-Ga2O3 Schottky junctions. The Schottky barrier height of ∼1.78 eV and the ideality factor of ∼1.06 were maintained after the 108-times on–off switching cycles. The fast switching with less energy dissipation and high durability of the PdCoO2/β-Ga2O3 Schottky junctions would be suitable for application in high-frequency power devices operating at high temperature.

Precision Adjustment of Probe Tilt Angle with RF Signal Detection Technique

This article proposes a breakthrough technique for the precision adjustment of the tilt angle of a radio frequency (RF) probe. The proposed technique utilizes the resonance generated at the probe tips. The adjustment technique is demonstrated in the frequency range between 190 and 340 GHz (300–GHz band). The proposed technique significantly reduces the variation in the probe-tilt angle in comparison with conventional manual inspection. Furthermore, the measurement repeatability of the proposed technique is better than that of the conventional manual technique. The proposed adjustment technique greatly improves the measurement repeatability of the on-wafer measurement in the 300–GHz band.

Implementation of a Highly-Sensitive and Wide-Range Frequency Measurement Using a Si3N4 MDR-Based Optoelectronic Oscillator

Microwave photonic technologies have been introduced for achieving broadband radio-frequency signal measurement. However, few of the proposed schemes mention the low-power radio-frequency signal detection, which stringently limits their practical applications in certain areas. In this paper, we designed and demonstrated a wideband low-power radio-frequency signal measurement system with optoelectronic oscillator. Here, the unknown radio-frequency signal matched the potential oscillation mode is allowable to be detected, amplified and estimated. The key component in the tunable optoelectronic oscillator is a silicon nitride micro-disk resonator with a very high Q-factor, which is utilized to achieve frequency selection as a microwave filter. A frequency measurement system range from 1 ∼ 20 GHz with radio frequency power as low as −105 dBm, measurement errors of ±375 MHz and the maximum gain of 61.7 dB were realized experimentally

Low-Power RF Signal Detection Using a High-Gain Tunable OEO Based on Equivalent Phase Modulation

A novel photonic method for low power radio-frequency (RF) signal detection by a tunable optoelectronic oscillator (OEO) with high gain based on equivalent phase modulation (EPM) is proposed and experimentally demonstrated. A dual-parallel Mach-Zehnder modulator is utilized to generate the EPM signal with a controllable optical carrier to sideband ratio, by which the gain to the RF signal by the OEO loop can be enhanced. A phase-shifted fiber Bragg grating (PS-FBG) with a narrow-band notch in its reflection band implements the phase modulation to intensity modulation conversion by removing one sideband of the EPM signal. The gain and noise performance of the detection system are theoretically analyzed and simulated. In the experiment, the maximum gain of 10.4 dB is obtained at 8 GHz, and the detection sensitivity for RF signals from 2 to 18 GHz are within the range of −87.7 to −84.3 dBm by using the developed detection system. Compared to normal phase modulation based scheme, the EPM-based system offers 9.1 dB higher gain. Utility of the proposed approach for detecting modulated RF signal is also investigated and an optimization scheme is discussed.