Industrial, Scientific And Medical Band Research Articles

Analysis of muscle implanted antenna performance with the variation of implantation depth

Abstract Implantation depth of Implantable Medical Devices (IMDs) is an important factor of communication quality between implantable antennas in IMDs and external devices. Therefore, it is required to study the effect of implantation depth on implantable antenna performance. In this article, dependence of resonant frequency and scattering parameters of a two-antenna system where one miniaturized meander-line antenna is placed within human muscle tissue layer operating at 2.45 GHz ISM (industrial, scientific and medical) band and a rectangular patch antenna placed outside human body, are tested. Here 15 values of implantation depth ranging over 5–35 mm inside muscle layer are taken and for each case resonant frequency and scattering parameters (S 11 and S 21) of the system are recorded. Statistical analysis has been performed to observe how these performance parameters are dependent on depth of implantation which may be varied at the time of surgery.

LoRa Communication Using TVWS Frequencies: Range and Data Rate

Low power wide area network (LPWAN) is a wireless communication technology that offers large coverage, low data rates, and low power consumption, making it a suitable choice for the growing Internet of Things and machine-to-machine communication applications. Long range (LoRa), an LPWAN technology, has recently been used in the industrial, scientific and medical (ISM) band for various low-power wireless applications. The coverage and data rate supported by these devices in the ISM band is well-studied in the literature. In this paper, we study the usage of TV white spaces (TVWS) for LoRa transmissions to address the growing spectrum demand. Additionally, the range and data rate of TVWS-based LoRa, for different transmission parameter values using different path-loss models and for various scenarios such as free space, outdoor and indoor are investigated. A path-loss model for TVWS-based LoRa is also proposed and explored, and the evaluations show that TVWS offers a longer range. This range and data rate study would be useful for efficient network planning and system design for TVWS-based LoRa LPWANs.

A High Performance All-Textile Wearable Antenna for Wristband Application.

A compact, conformal, all-textile wearable antenna is proposed in this paper for the 2.45 GHz ISM (Industrial, Scientific and Medical) band. The integrated design consists of a monopole radiator backed by a 2 × 1 Electromagnetic Band Gap (EBG) array, resulting in a small form factor suitable for wristband applications. An EBG unit cell is optimized to work in the desired operating band, the results of which are further explored to achieve bandwidth maximization via floating EBG ground. A monopole radiator is made to work in association with the EBG layer to produce the resonance in the ISM band with plausible radiation characteristics. The fabricated design is tested for free space performance analysis and subjected to human body loading. The proposed antenna design achieves bandwidth of 2.39 GHz to 2.54 GHz with a compact footprint of 35.4 × 82.4 mm2. The experimental investigations reveal that the reported design adequately retains its performance while operating in close proximity to human beings. The presented Specific Absorption Rate (SAR) analysis reveals 0.297 W/kg calculated at 0.5 W input power, which certifies that the proposed antenna is safe for use in wearable devices.

Dual-Band Antenna on 3D-Printed Substrate for 2.4/5.8 GHz ISM-Band Applications

In this paper, we present a dual-band antenna working at 2.45 GHz and 5.8 GHz. The design is based on two radiating rectangular slots with one upper Split Ring Resonator (SRR) to enhance the radiation pattern at 5.8 GHz, one Complementary Split Ring Resonator (CSRR), and three Split Rings (SR) to improve the input reflection coefficient. The dual-band antenna covers the 2.45 GHz and 5.8 GHz Industrial, Scientific and Medical (ISM) bands. The total size of the proposed antenna is 31 × 70 × 70 mm3. The proposed antenna was manufactured and tested. The attained gain is better than 7.5 dBi, and 6.5 dBi at 2.4 GHz and 5.8 GHz, respectively. The measured gain and input reflection coefficient have good correlation with the simulated results, covering the ISM bands around 2.45 GHz and 5.8 GHz. The performance of the proposed antenna is remarkable and suitable for applications where the size is not a severe limitation, such as sensors, LPWAN/WLAN modules, health care devices, base stations, IoT, and control applications.

ISM Band 2.4 GHz Wearable Textile Antenna for Glucose Level Monitoring

Wearable technology has recently attracted much interest for various uses. An essential component of the wearable system is the wearable antenna. Textile and non-textile materials have both been used to create wearable antennas. Textile antennas are very useful and widely used nowadays, particularly in body-worn applications monitoring health parameters. Fabricated using microstrip technology, textile antennas have various benefits, including small size, lightweight, simple fabrication, and ease of wear. In this study, a microstrip antenna is created utilizing a substrate made of jeans. It works between 2.4 to 2.5 GHz in the ISM (industrial, scientific, and medical) band. High-frequency structure simulator (HFSS) software was used to simulate two antennas, one with an incomplete and the other with a complete ground plane. Wearable antennas can protect the body from the impacts of RF radiation by utilizing the entire ground plane principle. Results from a vector network analyzer were obtained for the fabricated antenna (VNA). This antenna's main function is to track blood glucose levels. Blood's dielectric characteristics change when blood sugar levels fluctuate, affecting the antenna’s output frequency. There are two ways to monitor glucose levels. One method requires placing a finger on an antenna patch, while the other involves fixing an antenna to a person's arm and detecting the output frequency fluctuation. The antenna's resonant frequency raises in reaction to increased blood glucose levels. Therefore, these textile antennas are a great choice for non-blood sample monitoring of blood glucose levels.

Design of wearable antenna for ISM band application

A crescent-shaped wearable antenna is designed at 5.4 GHz for ISM (Industrial, Scientific, and Medical) band application and it is presented in this paper. The crescent shape is a combination of two circles and then the inner circle is removed from the outer circle for achieving a crescent shape. The crescent-shaped wearable antenna used jeans fabric as a substrate and it provides comfort and greater flexibility to wear on the human body. The proposed wearable antenna has a small thickness. The measured radiation parameters of wearable antenna-like return loss and VSWR are agreed well with performance evaluation simulations. It is simulated using HFSS software.

A Dual-Band Differential Intraoral Antenna and System for Wireless Data and Radiative Near-Field Power Transfer

Intraoral tongue drive system (iTDS) is a promising assistive technology for rehabilitating disabled persons. This article proposes a radiative near field power transfer (RNF-PT) system comprising an intraoral differential rectenna (rectifying antenna) and external power transmitter (RNF-Tx). A dual-band compact differential intraoral antenna operating in the Industrial, Scientific and Medical (ISM) band (2.45 GHz) and midfield band (1.9 GHz) is proposed for the data and power transmission modes, respectively. The proposed differential antenna and rectifier were designed and fabricated individually using a Rogers RT/duroid 6010 substrate. The differential rectifier shows a simulated conversion efficiency of 89.3% for a radio frequency (RF) input power of 14.78 dBm at 1.9 GHz with a 2 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{k}\Omega $ </tex-math></inline-formula> load. The maximum transmission coefficient of −25.95 and −24.93 dB was achieved at a separation of 22 mm for the closed and opened mouth conditions, respectively. The measured impedance bandwidths of the proposed antenna in both the closed and open mouth of the test subject are around 10% in the midfield band and around 9.5% in the ISM band, respectively. The measured peak gain in the minced pork and saline solution was −20.48 dBic, −18.25 dBic at the frequency of 1.9 GHz and −18.54 dBi, and −16.88 dBi at the frequency of 2.45 GHz, respectively. The specific absorption rate (SAR) values have also been analyzed through simulations for both data and power transmission modes and are found acceptable in the closed and open mouth placements. Based on these acceptable SAR values, the link margin was theoretically calculated where it could communicate over a reasonable distance. Thus, the proposed intraoral differential antenna with a rectifier is ideal for data and PT support in iTDS-based applications.

Daily Changes in Channel Occupancy in the 868 MHz ISM Band

Due to the rapid development of Internet of Things (IoT) systems operating in industrial, scientific and medical (ISM) frequency bands, many researchers have attempted to determine the amount of interference that can be expected in such systems. The basic information required for this purpose is the current occupancy of frequency channels in various geographical locations. It is known that the occupancy measurement must last long enough to allow for the detection of low duty cycle transmissions. In this paper, it is shown that fulfilling only this criterion may lead to unreliable results being obtained. In two measurement campaigns performed in two different locations, the occupancy of a selected sub-band in the 868 MHz ISM band was determined on the basis of two hour-long observations repeated several times a day. During a typical day, the ratio of the maximum and the minimum result depended on the location and reached a value of eight; however, on one day, a period of abnormally high channel usage reaching 65% was observed in the location in which typical values did not exceed 1%.

A New Miniaturized Low-Profile and Stable Dual-Band FSS with 2.5D Structure for ISM Bands

Based on 2.5-Dimensional (2.5D) frequency selective surface (FSS) structures, a new miniaturized frequency selective surface structure is proposed in this work to operate as a bandreject filter in the 2.4 GHz (2400 to 2483.5 MHz) and 5 GHz (5150 to 5350 MHz and 5470 to 5725 MHz) ISM (Industrial, Scientific, and Medical) bands. The FSS has the metallization layer formed by a square loop with an internal cross loop, with each geometry being responsible for a rejection frequency range. The main characteristics of the structure are discussed, emphasizing the resonance frequency variation as a function of the increasing number of vias. Numerical results are obtained through simulations using the commercial software ANSYS HFSS. In addition, by analyzing numerical results for structures with different numbers of vias, it was possible to obtain expressions for calculating the first resonance frequency for each geometry. The cell size of the 2.5D FSS of the proposed cell is only 0.0883 λ0, where λ0 corresponds to the free-space wavelength of the lower resonance frequency. The FSS presents dual polarization, angular stability for angles up to 50° and its simulated response presented two resonant frequencies, the first at 2.65 GHz and the second at 5.34 GHz, with relative bandwidths of 38.11% and 35.96%, respectively. For comparison and validation purposes, the prototype is fabricated and measured. A very good agreement between the simulation and measurement results is observed.

Reconfigurable planar inverted-F antenna for radio frequency identification tag and global positioning system applications

This paper presents the design of a reconfigurable planar inverted-F antenna (PIFA). The proposed antenna is designed and optimized to operate in two frequency bands. 2.4 GHz allocated to the industrial, scientific and medical (ISM) band for the identification of a set of vehicules within a given area, and 1.575 GHz allocated to the global positioning system (GPS) band to locate them outside. The ISM band is used for microwave frequencies for active radio frequency identification (RFID) tag, which is associated with the object to be identified. This antenna consists of two radiating elements connected by a positive-intrinsic-negative (PIN) diode to obtain the frequency reconfigurability. The first radiating element is connected to the ground plane by a shorting pin and excited by a 50 Ω coaxial feed line. Its total size is 30 mm × 50 mm × 7 mm. The substrate used is FR4 with constant dielectric relativity of 4.4 and a height of 1.6 mm. Computer simulation technology microwave studio (CST MWS) software is used to simulate and optimize the proposed reconfigurable PIFA antenna.

Design and performance analysis of wearable antenna for ISM band applications

ABSTRACT The paper proposes a wearable multiband antenna applicable for ISM (Industrial, Scientific and Medical) band, bluetooth, WiMAX, upper WLAN, fifth-generation (5G) smartphone applications, INSAT and radio altimeter, X-band, point-to-point hi-speed wireless, satellite TV, and C-band applications. This antenna is designed to function at resonance frequencies of 2.45 GHz, 4.6 GHz, 6.6 GHz and 8.2 GHz. The proposed textile antenna design dimensions are 50x80x0.56mm3.The antenna presented 47% impedance bandwidth covering the ISM band. The simulated value of the gain provided by the proposed wearable textile antenna is 5.59 dBi, 3.67 dBi, 3.99 dBi, 4.42 dBi at 2.45 GHz, 4.6 GHz, 6.6 GHz and 8.2 GHz resonant frequencies respectively.Simulations are therefore carried out using the human tissue model to show the specific absorption rate (SAR) value of the proposed antenna at different resonant frequencies. The antenna is fabricated and the simulated reflection coefficient validation is done with the measured results. The Antenna in off space provides 45% (2.1-3.32 GHz) impedance bandwidth. The antenna measured on the back of the human body provides percentage impedance bandwidth of 145% covering 1.4 to 8.8 GHz frequency band applicable for ISM band and other wireless applications.

Multilayer Archimedean spiral antenna design for dual-band intra-arm implantable biotelemetric smart health care monitoring system covering MICS and ISM bands

Abstract In this paper, a novel multilayer microstrip implant antenna (MIA) design based on the Archimedean spiral (AS) radiator element is presented for dual-band biotelemetric health care monitoring system. The proposed AS-MIA design has a layered structure consists of the spiral antenna elements and superstrate, namely layer #1 , layer #2 and layer #3 , respectively. While achieving the dual-band multi-layer implantable antenna design, firstly, each of the radiating elements in the respective layers is designed to cover separately in the desired bands, that is, layer#1 and layer#2 operate in the ISM (Industrial, Scientific, and Medical 2.4–2.48 GHz) and MICS (Medical Implant Communication Services 402–405 MHz) bands, respectively. Subsequently the ultimate multilayered AS-MIA design is formed by combining the individually designed layers. The compact implantable antenna has a dimension of r = 5 mm radius and h = 3.81 mm height, owning the electrically size of 0.067 λ 0 and h = 0.051 λ 0, respectively, where λ 0 is free space wavelength at 402 MHz in MICS band. Since the AS-MIA is intended to be used in an intra-arm smart health system, the simulated radiation performances of the antenna in a created numerical arm phantom are presented in the article. Also note that numerical analysis of the implant antenna was carried out using CST MW studio simulator based on finite integral method. The prototype of the implantable antenna was fabricated using Rogers 3210 substrate with electrical permittivity of ε r = 10.2. In-vitro return loss measurements were realized in skin mimicking gels, suggested in the literature. It was observed that in vitro measurement and simulation results were quite compatible with each other, except for some discrepancies due to the manufacturing and material tolerances during the preparation of the prototype antenna and skin mimicking gels. The proposed AS-MIA offers a dual-band operation with 15 and 16% S 11 bandwidth at each band of 402 MHz and 2.4 GHz respectively where |S 11| ≤ 10 dB criterion along with 50-Ω system is considered. Also the proposed design can be a good candidate to be used in dual-band medical implant communication systems with its miniature size and reasonable radiation characteristics.

Cavity Backed Slot Antenna Fed by a Stripline with SIW Structure and Vertical Coaxial Transition for Microwave Solid-State Heating Applications

This paper presents a new approach to feed multimode cavities used as microwave applicators for industrial and domestic microwave ovens using solid-state sources operating in the 2.45 GHz ISM (Industrial, Scientific and Medical) band (commonly used for industrial microwave applications). The feeding structure consists of a slot on the top side of the applicator cavity. The slot is fed by a shielded asymmetric stripline with a Substrate Integrated Waveguide structure (to preserve the stripline Transversal Electro-Magnetic (TEM) operation within the shield) and is N-connectorized. A first design of the antenna was obtained using state-of-the-art antenna theory assuming free-space radiation. Then, it was refined using a commercial simulation tool based on the Finite Element Method in the frequency domain to achieve VSWR values lower than 1.5 in the source bandwidth (from 2.42 to 2.48 GHz) when the antenna radiates into the applicator cavity. The design parameters of all the components making up this feeding structure are discussed throughout the paper. A prototype was built and measured in the laboratory. The experimental results are presented at the end of the paper along with the simulated ones, showing a very good agreement.

Performance evaluation of compact FSS‐integrated flexible monopole antenna for body area communication applications

SummaryThis article presents a compact wearable antenna integrated with a novel frequency selective surface (FSS) made of textile materials. The antenna can be applied in wearable health monitoring applications aimed at the 2.45‐GHz Industrial Scientific and Medical (ISM) band. An array of 4 × 4 octagonal slot‐shaped FSS (106 × 106 mm2) superstrate enhances the performance of the modified Koch curve planar monopole antenna (44.85 × 39 mm2). The Jeans substrate prototype with the overall dimensions of 1.128λ0 × 1.128λ0 × 0.319λ0 covers the bandwidth of 2.45‐GHz ISM band from 2.24 to 2.76 GHz (S11 ≤ −10 dB). The band rejection and reflective nature of the proposed FSS suppress the back radiation and improves the antenna's gain by −20 dB and 6.3 dBi, respectively. The specific absorption rate (SAR) level is reduced to 0.445 W/kg from 24.995 W/kg with a higher reduction rate of 98.21%. Many literature reports produced higher gain and lower SAR but exhibited reduced efficiency when the antenna is placed near the human body. The wearable antenna's frequency response tends to vary under bending conditions for narrowband antennas. Wide‐band monopole antennas produce omnidirectional radiation pattern which tends to affect human body tissues. So stable polarization‐insensitive FSS is placed behind the antenna to enhance the antenna's gain and avoid back radiation. The proposed antenna exhibits stable performance under bending conditions with fractional bandwidth of 22.2%, gain of 8.83 dBi, and produces a better efficiency of 91.30% when the antenna is positioned in the vicinity with human body models. The experimental validation shows that the proposed antenna is a promising candidate for wireless body area networks.

Compact Dual Band and Dual Polarized CPW-Fed Triangular Shaped Wearable Antenna for ISM band Applications

ABSTRACT A coexisting compact dual coplanar waveguide (CPW)-fed dual-band and dual-polarized triangular-shaped wearable antenna (TSWA) is proposed for 2.45 GHz and 5.8 GHz ISM (Industrial, Scientific and Medical) frequency bands. The proposed antenna of area 722 mm2 is fabricated on polyimide substrate (thickness of 1.6 mm and relative permittivity of 3.5). The two identical inverted-L-shaped feed stubs are employed orthogonally in wide triangular slot to provide both horizontally and vertically polarized radiations in both ISM bands. An additional Y-shaped copper strip is introduced to isolate the two inverted-L-shaped feed stubs in order to achieve higher isolation in both 2.45 and 5.8 GHz operational frequency bands. The proposed TSWA achieves similar −10 dB impedance bandwidths of 21.7% (2.30 ̶ 2.86 GHz) and 14.26% (5.60 ̶ 6.46 GHz) respectively for dual-polarized radiations along with more than 20 dB isolation in both 2.45 and 5.8 GHz ISM bands. The effect of human loading on performance of proposed TSWA is also studied. The proposed antenna is designed, fabricated, and tested. The simulated results are verified and validated with measured ones and thus, makes it suitable for wearable ISM bands applications.

Dual-band microstrip patch antenna for IoT application

Internet of Things (IoT) primarily based application requires integration with the wireless communication technology to make the application data with ease available. In this paper, a modified 12 mm x 16 mm x 1.6 mm micro strip patch antenna has been proposed for IoT applications at 2.4 Giga Hertz (GHz) in the Industrial Scientific and Medical (ISM) band. This wideband antenna is designed using Flame Retardant4 (FR4) material as the substrate. The multiband operating characteristics have been achieved by radiating strips to the 50 feed line. Proposed wideband antenna covers frequencies ranging from 1.8 GHz to 3 GHz and 5.3 GHz to 6.9 GHz for -10 dB return loss. The results are analyzed and discuss in term of return loss, Voltage Standing Wave Ratio (VSWR), efficiency and gain. The proposed design has a maximum losses of -31.59 dB at 2.4 GHz and -16.94 dB at 6 GHz. The developed antenna can be useful for several wireless communication applications, such as 2.4 GHz Bluetooth, Wireless Local-Area Network (WLAN) (2.4/5.8 GHz), Worldwide Interoperability for Microwave Access (WiMAX) (5.5 GHz), ISM band and IoT applications.

Smart antenna design for mobile application

Digitalization is becoming more and more important. Building smart houses and industries to offer humans longer lives is one of the main goals of the digitization movement. The main aim of this work is to make those verbal exchange modules more powerful with the aid of either improving the antennas to have a higher layout or changing it with new varieties of antennas that are better able to facilitate powerful verbal exchange. This paper proposes an antenna that can be applied to a verbal exchange module to be able to perform inside the Industrial, Scientific, and Medical (ISM) band at 2.4 GHz. After designing and simulating a complete Printed Circuit Board (PCB) antenna, it found that a few designs produced advanced simulation effects in terms of gain, reflection coefficient, voltage standing wave ratio (VSWR), and band width. Always-pointing antennae are protected by the layout of the antenna, allowing it to protect features inside the Global Positioning System (GPS) and ISM (Industrial, Scientific, and Medical) bands for Wi-Fi devices.

Compact 2*1 Reader Array Antenna Operating in ISM Band for RFID Applications

This paper proposes a compact 2*1 reader array antenna for RFID system having high directivity, good gain, and good reflection coefficient. The structure consists of two main radiating rectangular patch antennas connected in parallel with a common impedance of (50 Ω). These patches are printed on an RT/duroid 5880 substrate possessing a dielectric constant εr equal to 2.2 and 0.0009 as a loss tangent. It operates in ISM (Industrial, Scientific and Medical) band with a resonant frequency of 5.8 GHz. The structure is implemented on a compact size of 38.77× 59.44× 1.6 mm3 equivalent to an electrical size of 0.74λ0× 1.14λ0× 0.03λ0, where λ0 is the free-space wavelength at the resonant frequency. The gain achieved by the final design of the proposed antenna is equal to 9.83 dB, the directivity is around 9.99 dB and the coefficient of reflection (S11) is equal to -49.48 dB. The proposed antenna design is optimized and simulated using Computer Simulation Technology software (CST Microwave Studio).

Developing of Bluetooth mesh flooding between source-destination linking of nodes in wireless sensor networks

Bluetooth uses 2.4 GHz in ISM (industrial, scientific, and medical) band, which it shares with other wireless operating system technologies like ZigBee and WLAN. The Bluetooth core design comprises a low-energy version of a low-rate wireless personal area network and supports point-to-point or point-to-multipoint connections. The aim of the study is to develop a Bluetooth mesh flooding and to estimate packet delivery ratio in wireless sensor networks to model asynchronous transmissions including a visual representation of a mesh network, node-related statistics, and a packet delivery ratio (PDR). This work provides a platform for Bluetooth networking by analyzing the flooding of the network layers and configuring the architecture of a multi-node Bluetooth mesh. Five simulation scenarios have been presented to evaluate the network flooding performance. These scenarios have been performed over an area of 200×200 meters including 81 randomly distributed nodes including different Relay/End node configurations and source-destination linking between nodes. The results indicate that the proposed approach can create a pathway between the source node and destination node within a mesh network of randomly distributed End and Relay nodes using MATLAB environment. The results include probability calculation of getting a linking between two nodes based on Monte Carlo method, which was 88.7428 %, while the Average-hop-count linking between these nodes was 8. Based on the conducted survey, this is the first study to examine and demonstrate Bluetooth mesh flooding and estimate packet delivery ratio in wireless sensor networks

Sensing and analysis of spectrum holes in ISM band using USRP testbed

The spectrum frequency in the wireless communication industry is getting great attention due to the internet of things (IoT) technology's growth. However, the radio spectrum's frequency band use is limited because the primary user for specific services can cause spectrum interference as multiple users use the same spectrum frequency. Meanwhile, at each spectrum frequency, the number of users and utilization time are distinct. These will create vacancies for spectrum frequency assigned to the primary user. A new alternative in using the cognitive radio (CR) spectrum is accessible to these vacancies. This paper analyzed the frequency spectrum in the industrial, scientific and medical (ISM) band and identified spectrum holes for transmission by the secondary users. This work employed a realistic approach by measuring the spectrum using Universal Software Radio Peripheral (USRP) devices. Thus, the spectrum holes in the frequency spectrum had distinguished by using an energy detection technique. In the energy detection technique, the threshold energy level is set and then compared with the energy detector output to identify the primary user's existence (PU). The result indicates that 0.61% of spectrum holes have been detected in the 2.43-2.44 GHz range. This range is sufficient for home appliances, radio frequency peripherals (RF), and bluetooth devices.