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This chapter presents novel passive and active wearable sensors for biomedical systems, energy harvesting, and communication devices. Design tradeoffs, simulation, and measured results of compact efficient sensors for communication, energy harvesting, IoT, and healthcare systems are discussed in this chapter. The new sensors are green sensors with an energy harvesting unit. The sensor electrical parameters near the human body were evaluated by employing RF CAD software. The sensors are flexible passive and active devices with high efficiency and low cost. Low-cost sensor may be developed by printing the printed antenna with the antenna feed network and the active components on the same board. Efficient metamaterial sensors were developed to improve the system electrical performance. The resonant frequency range of the sensors, with Circular Split-Ring Resonators CSRRs, is lower by 5% to 11% than the sensors with CSRRs. The directivity and gain of the sensors with CSRRs are higher by 2.5dB than the sensors without CSRRs. For S11 lower than –6 dB, the bandwidth of the novel metamaterial sensors may be around 15 to 55%. The directivity and gain of the new metamaterial sensors are around 5 dBi to 7.5 dBi. The receiving active sensor gain is 12 ± 3 dB. The transmitting active sensor gain is 13 ± 3 dB.
Department of Electrical Engineering, Ort Braude College, Karmiel, Israel
Senior RF and communication systems researcher and consultant in High Tech Companies, Haifa, Israel
*Address all correspondence to: sabban@netvision.net.il
1. Introduction
Compact resonators and antennas are presented in [1, 2, 3, 4, 5, 6]. The efficiency of compact resonators is low. Several types of compact wearable antennas, such as printed dipoles and microstrip antennas, are presented in [2, 3, 4, 5, 6]. Printed metamaterial sensors are employed in wireless communication systems and were presented in several publications, see [2, 3, 4, 5, 6, 7]. Materials with periodic artificial structures are called metamaterials. The metamaterial structure and components define the electrical properties of the material. In [8, 9, 10, 11, 12, 13, 14] metallic posts structures and periodic split-ring resonators (SRRs) are used to produce structures with required permeability and dielectric constant. Metamaterials may be employed to develop efficient sensors for RF, medical and IoT wearable devices [12, 13, 14, 15, 16]. The bandwidth and gain of the antenna presented in [8] are like those of patch antennas. Materials with negative dielectric permittivity are described in [9]. A model and setup to compute and measure the polarity of SRRs are described in [10]. A dual-band transmission-line metamaterial antenna with two transmission-line arms is described in [14]. The radiation efficiency of the antenna at 3.3 GHz is around 60% with 2.6 dBi directivity, and 0.8 dBi gain. Antennas such as patches, loops, and FIPA antennas have low efficiency [2, 3, 4, 5, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29]. In communication and healthcare systems, the system polarization may be vertical, horizontal, or elliptical. In these systems, the radiating elements must be circular or dual-polarized. In [15, 16, 17] compact metamaterials sensors for healthcare devices are presented. Measurements of wearable sensors are presented in [19]. Active antennas for communication, medical, and IoT devices are presented in [20]. As presented in [30] Wearable healthcare devices are used to increase disease cure and prevention. A wireless device with thermal-aware protocol is presented in [30]. Wearable sensors and antennas for healthcare and RF systems are presented in [31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41]. Dual-polarized wearable antennas for healthcare applications are presented in [41]. Dual polarized metamaterial antennas have significant advantages over regular printed antennas, such as high efficiency and gain. The sensors electrical parameters on and near the human body were evaluated, see [2, 3, 4, 5, 6], by employing RF CAD software [42, 43].
In this chapter, metamaterials technology is used to develop high-efficiency sensors and antennas with harvesting energy units for medical, communication, and IoT devices. The energy harvesting units connected to the system provide compact self-powered efficient sensors.
The antennas bandwidth is around 20 to 45%, for VSWR, better than 3:1. The gain of the antennas with CSRRs is around 7.5 dB. The sensors efficiency is higher than 90%.
Wearable systems and devices will be in the next following years, an important part of individuals’ daily lives. Wearable healthcare systems may measure and record several medical parameters such as heartbeat rate, blood pressure, sweat rate, arterial blood pressure, body temperature, electrocardiograms, and electro-dermal activity. Wearable devices may provide monitoring and scanning features that are not provided by cellular phones and other computing devices. Wireless devices and technologies are employed to analyze and process the data collected by the healthcare devices. The collected medical information may be transmitted to the healthcare center to analyze the collected medical information. This process may send a message to the physician to call the patient that needs immediate medical treatment.
2.1 Features of wearable healthcare and sport devices
Healthcare wearable systems monitor healthcare centers daily activities.
Wearable systems monitor and operate companies’ daily activities and systems.
Healthcare wearable systems assist and help patients such as Asthma patients, Diabetes patients, Alzheimer’s disease patients and Epilepsy patients.
Healthcare wearable systems and devices may help to solve Obesity problems, Sleep disorders, and cardiovascular diseases.
Wearable healthcare systems may measure and record several medical parameters such as heartbeat rate, blood pressure, sweat rate, arterial blood pressure, body temperature, electrocardiograms, and electro-dermal activity. The application of WBANs in medical centers with energy harvesting units, where the medical parameters of a large number of patients are constantly being monitored, is presented in Figure 1.
Figure 1.
Green wireless body area network, WWBAN, health monitoring sensors and system with energy harvesting units.
2.2 IoT systems
IoT devices are wireless communication modules of interrelated computing systems, mechanical machines, personal devices, healthcare sensors, and digital machines that possess unique identifiers (UIDs). IoT devices and systems consist of wireless communication modules, processors, sensors, and radiating elements. IoT devices and systems transmit, receive, and process data from networks connected to the Internet web. IoT devices and systems are connected to an IoT gateway network where they gather data that is analyzed online or sent to information centers to be processed and shared with specific IoT modules and devices. The polarization of the receiving channel of IoT and medical devices should match the polarization of the transmitting channel. In several communication devices, the polarization is not defined. In these cases, the receiving antenna should be dual-polarized. IoT systems are significant in daily work and treatment in healthcare centers. IoT modules and systems may connect several healthcare devices and healthcare information centers to improve healthcare treatment. Efficient medical and IoT systems result in low-cost healthcare treatment.
Efficient medical and IoT systems and devices are used to automate healthcare systems and procedures, to minimize organization and healthcare centers facilities and to lower labor costs.
IoT systems may transmit data through a communication system without the need of human to computer interaction or human-to-human involvement.
IoT systems can provide complete control over daily tasks and services in healthcare centers and organizations. IoT systems improve people’s daily life and help companies to function more efficiently and smarter.
A block diagram of IoT medical device is presented in Figure 2.
Figure 2.
IoT medical system block diagram.
IOT Devices and Systems Major Disadvantages-
In several IoT devices and systems modules and information are shared between several machines and devices. This fact increases the threat that hackers can steal confidential data and corrupt devices connected to this IoT system.
A bug in the IoT devices and system may corrupt devices and modules connected to this IoT system.
2.3 Wireless communication devices and cellular phones features
The first generation of cellular phones began in the 1980s and used 1G technology. 1G technology of mobile phones uses analog radio systems. In the last decade, communication technology was improved rapidly and is employed in modern mobile phones. Table 1 presents the improvement of mobile phone communication technologies.
Technology
1G
2G
3G
4G
5G
Data Speed
2.4 kbps
64 Kbps
3 Mbps
1Gbps
20 Gbps
Electronic Technology
Analog
Digital
Audio and video
Wi-Fi
Wi-Fi, wireless
Battery life
Few hours
Longer life cycle
Longer life cycle
Better life cycle
Power savings
Dimensions
Big and large
Smaller
Size reduction
Compact
Compact
Security
Low security
call and text encryption
Improved security
High security
High security
Capacity
Limited
Improved
Large
Large
High capacity
Table 1.
Comparison of cellular phone technologies.
5G Technology Main features
High data transmission speed and high capacity.
Connected and supportable to Wireless World Wide Web.
Large broadcasting of data in Gbps.
Observe TV programs with HD Clarity and read newspapers.
Improved information transmission than that of 4G Generation.
Better phone memory, improved dialing speed, improved clarity in audio and video features.
5G technology provides high resolution to cellular phone users and large bandwidth sharing.
3. Compact wearable dual polarized antenna for IoT and medical applications
The antenna with CSRR and metallic strips is presented in Figure 3a. The printed dipole matching network and the metallic strips are etched on the first layer with thickness of 0.16 cm. The radiating element with CSRR is printed on the second layer with thickness of 0.16 cm. The size of the antenna network with the energy harvesting module is 21.5×4.5 cm. The printed slot antenna is vertically polarized. The printed dipole is horizontally polarized. The resonant frequency of the dipole with CSRR is around 0.33GHz, which is lower by 15% than the resonant frequency of the printed dipole without CSRR. Many communications, IoT and healthcare systems operate in the frequency range between 0.1 and 0.55 GHz. The computed S11 and antenna gain are shown in Figure 4. The measured antenna bandwidth is around 45% for S11 lower than -6 dB. The dipole and the slot radiate in the z axis direction. The measured directivity and gain of the antenna with CSRR are around 5.5 dBi, as presented in Figure 5. The feed network of the antenna in Figure 3a was optimized, see Figure 3b, to yield S11 lower than -6 dB in the frequency range from 0.18 to 0.4 GHz, around 60% bandwidth, as presented in Figure 6. The dimensions of the antennas presented in this chapter are given in Table 2.
Figure 3.
(a). Antenna with CSRR and with energy harvesting unit, (b). optimized sensor with CSSR and metallic strips.
Figure 4.
Gain and S11 of the dual-polarized antenna with metallic strips and CSRR.
Figure 5.
Radiation pattern and gain of the antenna with metallic strips and CSRR.
Figure 6.
S11 of the optimized dual-polarized antenna with metallic strips and CSRR on human body.
Electrical performance comparison between wearable antennas without and with CSRR.
The sensors electrical parameters, presented in this chapter, on and near the human body were evaluated, see [2, 3, 4, 5, 6, 7], by employing RF CAD software [42, 43]. The theoretical and equations used to design the sensors presented in this chapter are given in previous publications, see [2, 3, 4, 5, 6, 7]. The energy harvesting module is connected to the antenna network feed line, as presented in Figure 3. The energy harvesting module can charge the battery when the switch is connected to the harvesting unit. Electromagnetic AC power is converted to DC power by employing a rectifying diode. The rectifier may be a half-wave rectifier or a full-wave rectifier. As shown in Figure 3, the harvesting module has an antenna, a rectifying circuit, and may recharge the device battery.
A receiving self-powered active sensor is presented in Figure 7. The energy harvesting module acts as a dual-mode electromagnetic harvesting module. A switch may connect the LNA to the energy harvesting module. The energy harvesting module charges the battery. The Low Noise Amplifier is matched to the receiving antenna via a matching network. The LNA TAV541 is a linear PHMET amplifier. At 2 GHz, the amplifier has 0.45 dB Noise Figure and 18.5 dB gain. The LNA P1dB, at 2 GHz, is 19 dBm at the output port. The LNA specifications are listed in Table 3. A DC bias network supplies the required voltages to the amplifiers. The Low Noise Amplifier is matched to the receiver via an output-matching network. The sensor dimensions are around 21.5×5×1.9 cm. Gain and reflection coefficient of the metamaterial sensor is presented in Figure 8. The receiving active sensor gain as presented in Figure 9 is 12 ± 3 dB, and the noise figure is better than 1 dB, for frequencies from 0.1GHz to 1GHz. The active metamaterial antenna was evaluated with Triquint LNA TQP3M9028. The amplifier specifications are given in Table 3. The active antenna gain with TQP3M9028 LNA is 11.1 ± 2.5 dB from 0.15 to 0.9GHz, as presented in Figure 10. The sensor noise figure, with TQP3M9028 LNA, for frequencies from 0.15GHz to 1GHz is better than 1.9 dB. The measured performance of the sensors with different LNAs is listed in Table 4. The active antennas with LNA TAV541 has better noise figure and higher gain. The sensor with LNA TQP3M9028 has a better 1dBc compression point and gain flatness.
Figure 7.
Dual polarized receiving sensor with CSRR and with energy harvesting unit.
Figure 8.
S11 and gain of the dual-polarized antenna with CSRR and matching network.
Specification
TAV541, Mini Circuit
TQP3M9028, Triquint
Frequency, GHz
0.4–3
0.05–4
Gain at 2 GHz
18.5 dB
14.5 dB
N.F at 2GHz
0.45 dB
18 dB
P1dB at 2GHz
18.5 dBm
20.5 dBm
OIP3 at 2GHz
32 dBm
35 dBm
Operating Temp.°C
−40 – 80
−40 – 80
Max. Input power
17 dBm
17 dBm
Vgs, Volt
0.4
0.4
Vds
3 V, Ids = 60 mA
5 V, Ids = 85 mA
Supply voltage, V
±5
±5
Package type
Surface Mount
Surface Mount
Table 3.
Comparison of the specification of the S-band low noise amplifiers.
Figure 9.
Active receiving dual polarized receiving sensor gain, with LNA.
Figure 10.
Active receiving dual polarized receiving sensor gain, with TQP3M9028 LNA.
Parameter
Sensor with TAV541
Sensor with TQP3M9028
Frequency
0.1–1 GHz
0.15–0.9 GHz
VSWR
3:1
3:1
Gain
11 ± 2.5 dB
12 ± 3 dB
N.F at 1GHz
1 dB
2 dB
P1dB at 1GHz
19.0 dBm
20 dBm
Max Input power
17 dBm
17 dBm
Vgs, Volt
0.5
0.5
Vds
3 V, Ids = 55 mA
5 V, Ids = 80 mA
Dimensions
21.5×5×1.9 cm
21.5×5×1.9 cm
Table 4.
Comparison of the sensors measured performance with different LNA Amplifiers.
5. Wearable self-powered active transmitting antenna
A transmitting self-powered active sensor is presented in Figure 11. The energy harvesting module acts as a dual-mode electromagnetic harvesting module. The harvesting module can be part of a healthcare, IOT, and cellular phone. A switch may connect the transmitter battery to the energy harvesting module. The energy harvesting module charges the battery. Two power amplifiers were used to develop the metamaterial active sensor. The first amplifier is an MMIC GaAs MESFET VNA25, the second amplifier is an MMIC GaAs PHEMT HMC459. The amplifier specification is listed in Table 5. A DC bias network supplies the required voltages to the amplifiers. The sensor dimensions are around 21.5×5×1.9 cm. The active transmitting sensor VSWR, computed and measured, is better than 3:1 for frequencies from 0.25 to 0.45GHz. The computed and measured antenna gain are around 5.8 dBi, as presented in Figure 12. The active computed and measured antenna gain with HPA VNA25 is 13 ± 3 dB 1 for frequencies from 0.1 to 0.8 GHz. The transmitting sensor S21 parameter is shown in Figure 13. The active computed and measured antenna gain with the HMC459 HPA is 12 ± 4 dB for frequencies from 0.1 to 1 GHz, as shown in Figure 14. The transmitting sensor output power is around 19.5 dBm. The measured electrical performance of the sensors with the HPAs is listed in Table 6. The active antenna with VNA25 HPA has better gain flatness, higher gain, and lower DC power consumption. The transmitting antenna with HMC459 HPA has higher input and output power, and higher 1 dBC compression point. The HPA HMC459 has wider bandwidth from 1 to 18GHz. Photos of the metamaterial sensors, with CSSR and metallic strips, are shown in Figure 15.
Figure 11.
Dual polarized transmitting sensor with CSRR and with energy harvesting unit.
Specification
VNA25, Mini Circuit
HMC459, Triquint
Frequency GHz
0.4–2.5
DC–18
Gain dB at 1.8 GHz
17.5
16.5
N.F at 1.8 GHz
5.0 dB
3.8 dB
P1dB at 1.8 GHz
18.5 dBm
24 dBm
Max Input power
10 dBm
16 dBm
OIP3 at 1.8 GHz
28 dBm
29 dBm
Vgs, V
0.5
0.5
Vds
5 V, Ids = 85 mA
8 V, Ids = 290 mA
Supply voltage, V
±5
±8
Package
Surface Mount
Surface Mount
Temp. Range °C
−40 – 80
−40 – 80
Table 5.
Electrical Specification of the HPA Amplifiers.
Figure 12.
Radiation pattern and gain of the dual-polarized antenna with metallic strips and CSRR.
Figure 13.
Active transmitting dual polarized sensor gain, with HPA VNA25.
Figure 14.
Active transmitting dual polarized sensor gain, with HPA HMC459.
Parameter
Sensor with VNA25
Sensor with HMC459
Frequency
0.1–1GHz
0.15–0.9 GHz
VSWR
3:1
3:1
Gain
13 ± 3 dB
12 ± 4 dB
N.F at 1 GHz
6 dB
5 dB
P1dB at 1 GHz
19.0 dBm
24 dBm
Max Input power
10 dBm
16 dBm
Vgs
0.50 V
0.50 V
Vds
5 V, Ids = 85 mA
8 V, Ids = 290 mA
Dimensions
21×6×2cm
21×6×2cm
Table 6.
Comparison of the sensors performance with different HPA amplifiers.
Figure 15.
Photos of the metamaterial antenna. a. Feed layer b. antenna with CSSRs c. CSSR.
6. Wearable metamaterial antennas for communication, healthcare, and IoT systems
The antenna’s electrical parameters performance near the human body were computed by employing the antenna and human body model presented in Figure 16a. The dielectric constant and conductivity of human body tissues are given in Table 7 [21, 22]. The effect of the antenna location on the human body is simulated by evaluating the antenna’s electrical parameters on human body. The variation of the dielectric constant of the body tissues affects the electrical performance of the antenna. The antenna resonant frequency may be shifted up to 10% at different locations of the antenna on the patient’s body. As shown in Table 7, the dielectric constant of fat tissues is 4.7, 41 in the skin tissues, 43 in the stomach area, and up to 128.1 in the small intestine tissues. The antennas may be placed inside a belt, as shown in Figure 16b. The antenna’s electrical characteristics were computed and measured for air spacing between the sensors and human body up to 25 mm at different locations on the human body. Measurements of wearable sensors and antennas are done by using a phantom with sugar, salt, and water that represent the dielectric constant and conductivity of human body tissues [2, 3, 4, 5, 19]. The antenna’s electrical and mechanical characteristics were optimized to achieve the best antenna electrical and mechanical performance. Wearable antennas and sensors measurements and setup are discussed in [2, 3, 4, 5, 19].
Figure 16.
(a) Model of wearable antenna environment; (b) wearable medical system on human body.
Tissue
Parameter
440 MHz
600 MHz
1 GHz
1.25 GHz
Fat tissues
σ
0.047
0.05
0.054
0.06
ε
5.00
5.00
4.72
4.55
Stomach tissues
σ
0.71
0.75
0.96
0.98
ε
42.7
41.40
39.66
39.00
Blood
σ
1.76
1.78
1.91
1.99
ε
57.2
56.5
55.40
55.00
Skin
σ
0.58
0.6
0.63
0.77
ε
41.6
40.45
40.25
39.65
Lung tissues
σ
0.27
0.27
0.27
0.28
ε
38.4
38.4
38.4
38.4
Kidney tissues
σ
0.90
0.90
0.90
0.91
ε
117.45
117.45
117.45
117.45
Colon tissues
σ
1.00
1.05
1.30
1.45
ε
63.5
61.9
60.00
59.40
Small intestine
σ
1.74
1.74
1.74
1.74
ε
128.1
128.1
128.1
128.1
Table 7.
Electrical parameters of human body tissues [16, 17].
Table 2 presents a comparison between computed and measured results of sensors without and with CSRR. Table 8 presents a comparison of computed and measured results of compact wearable antennas.
Input Power dBm
Efficiency %
Remarks
−4−−6
8–12
Low Efficiency
−3−−2
28–32
Low Efficiency
−1 − +1
48–52
Good Efficiency
2–3
52–56
Good Efficiency
4–5
52–56
Good Efficiency
6–8
56–58
Good Efficiency
9–11
60–65
Best Efficiency
Table 8.
Measured harvester efficiency as function of input collected power.
Tables 2 and 8 verify that there is a good match between computed and measured results. Electrical performance of several passive and active antennas (such as dipoles, loop, slot and other antennas) is discussed in [2, 3, 4, 5, 6]. Medical, wearable wireless BAN, IoT, and monitoring systems with wearable BAN systems are shown in Figure 17. Hospitals, Health care centers and medical staff can be contacted from everywhere at any given time.
Figure 17.
Green medical, WWBAN, and IoT monitoring system with WBAN networks with energy harvesting units.
As presented in Figure 3, the energy harvesting unit consists of an antenna, rectifying diode and circuit, and a rechargeable battery. The energy harvesting unit and the radiating element provide a self-powered device. The rectifier diode converts electromagnetic energy, AC energy, to direct current (DC energy). Two types of diode rectifiers are usually used a half-wave rectifier or a full-wave rectifier [44, 45, 46, 47]. A half-wave rectifier is presented in Figure 18. A half-wave rectifier converts only the half cycle of the positive voltage. It allows harvesting only one-half of the electromagnetic wave. The efficiency of the half-wave rectifier is around 41%. A full-wave bridge rectifier is shown in Figure 19. The bridge full-wave diode rectifier circuit converts electromagnetic energy to DC energy. The bridge rectifier consists of four diodes D1 through D4, as shown in Figure 19. The rectifier output DC voltage, VODC=2Vm/π. By connecting a capacitor in shunt to the resistor, as shown in Figure 19, the rectifier output voltage may be improved. The full-wave rectifier efficiency is around 81%. Electromagnetic power amount in public centers, stadiums, hospitals, and malls may range from 1 μW/cm2 to 5 mW/cm2. The harvesting system efficiency increases as function of the electromagnetic power collected by the harvesting system, as listed in Table 8. The amplifier amplifies the input power collected by the energy harvesting system and improves the efficiency of the harvesting system. Results listed in Table 8 are also presented by companies that manufacture commercial RF energy harvesting systems, see [2, 3, 4, 5, 6, 7, 44, 45, 46, 47]. If the RF radiating sources are close to the harvesting system, the RF power collected by the harvester will be higher.
Figure 18.
Diode voltage rectifier with a capacitor, half wave.
Figure 19.
Diode bridge voltage rectifier with a capacitor, full wave.
Energy harvesting units provide green renewable energy and may eliminate the usage of power cords and the need to replace batteries frequently. Wearable medical devices with energy harvesting modules for wireless communication, IoT, and medical applications are presented in Figure 20. As presented in Figure 20, the medical device and harvesting module with a compact battery charger are located on the patient’s shirt.
Figure 20.
Wearable RF system with energy harvesting unit for IoT, 5G, and healthcare systems.
In 2022 almost everyone uses cellular phones, communication networks, tablets, and other RF communication systems. There is a huge increase in the amount of RF energy in the air. The expected amount of radio waves in the air in 2022 was around 60 Exa-bytes, EB, per month. The expected amount of RF energy in the air in 2025 is expected to be around 170 Exa-bytes per month. In RF energy harvesting modules, the radio frequency waves propagating in air can be received by the antennas and converted to DC power that is employed to charge batteries, sensors, and other wearable devices.
The active and passive sensors and metamaterials antennas presented in this chapter are wideband, efficient, compact, and low-cost. RF energy harvesting modules are connected to the antennas and sensors. Electromagnetic waves propagating in the air can be collected by the antennas and converted to DC power that may recharge the healthcare, computing system batteries, wearable sensors, and other RF modules. Evaluation of efficient active and passive wearable antennas and sensors is one of the most significant goals in the evaluation of wearable healthcare devices, medical sensors, IoT, wireless communication and medical systems. Passive and active metamaterial compact antennas and sensors characteristics such as gain, matching, noise figure, efficiency, bandwidth, and radiation pattern are presented in this chapter. The directivity and gain of the sensors with CSRRs are higher by 2.5 dB than the sensors without CSRRs. For S11 lower than -6 dB the bandwidth of the novel metamaterial sensors may be around 15 to 55%. The directivity and gain of the new metamaterial passive sensors are around 5 to 7.5 dBi. The receiving active sensor gain is 12 ± 3 dB. The transmitting active sensor gain is 13 ± 3 dB.
The metamaterial antennas and sensors discussed in this research may be used in wireless communication devices, computing networks, IoT devices, sport, and medical applications. Metamaterial technology is employed to design compact, efficient antennas and sensors. The receiving dual-polarized antenna network with the energy harvesting module, size is 21.5×4.5 cm. The printed slot antenna is vertically polarized. The printed dipole is horizontally polarized. The resonant frequency of the dipole with CSRR is around 0.33 GHz, which is lower by 15% than the resonant frequency of the printed dipole without CSRR. The measured antenna bandwidth is around 45% for S11 lower than -6 dB. The measured directivity and gain of the antenna with CSRR are around 5.5 dBi. The S11 of the optimized receiving metamaterial antenna is lower than -6 dB in the frequency range from 0.18 to 0.4 GHz, around 60% bandwidth. The receiving active sensor gain with TAV541 LNA is 12 ± 3 dB, and the noise figure is better than 1 dB, for frequencies from 0.1 to 1GHz.
The active computed and measured transmitting antenna gain with HPA VNA25, is 13 ± 3 dB 1 for frequencies from 0.1 to 0.8 GHz. The transmitting sensor output power is around 19.5 dBm.
Electromagnetic power amount in public centers, stadiums, hospitals, and malls may range from 1 μW/cm2 to 5 mW/cm2. The harvesting system efficiency increases as function of the RF power collected by the harvesting system. The efficiency of the harvesting system is around 50% for 0 dBm input power. However, the efficiency of the harvesting system is around 60% for 10 dBm input power.
The antennas and sensors presented in this chapter may be used in medical devices that improve the daily health of patients. Wearable antennas and healthcare devices are an important choice for healthcare organizations, hospitals, and patients. The wearable sensors presented in this chapter support the development of personal healthcare systems with online immediate medical staff responses to treat and improve patients’ health.
References
1.James JR, Hall PS, Wood C. Microstrip Antenna Theory and Design. London, UK: Institution of Engineering and Technology (IET); 1981
2.Sabban A. New compact wearable metamaterials circular patch antennas for IoT, medical and 5G applications, MPDI. Applied System Innovation. 2020;3(4):42. DOI: 10.3390/asi3040042
3.Sabban A. Wearable Communication Systems and Antennas. 2nd ed. Bristol, UK: IOP Publishing Ltd; 2022. ISBN: 978-0-7503-5220-8
4.Sabban A. Wearable Circular Polarized Antennas for Health Care, 5G, Energy Harvesting, and IoT Systems. Electronics. MDPI Publication. Jan 2022. (ISSN 2079-9292)
5.Sabban A. Novel Wearable Antennas for Communication and Medical Systems. Boca Raton, FL, USA: Taylor & Francis Group; 2017
6.Sabban A. Wideband RF Technologies and Antennas in Microwave Frequencies. Hoboken, NJ, USA: Wiley; 2016
7.Sabban A. Low Visibility Antennas for Communication Systems. Boca Raton, FL, USA: Taylor & Francis; 2015
8.Rajab K, Mittra R, Lanagan M. Size reduction of microstrip antennas using metamaterials. In: Proceedings of the 2005 IEEE APS Symposium. Washington, DC, USA: IEEE; 3–8 Jul 2005
9.Pendry JB, Holden AJ, Stewart WJ, Youngs I. Extremely low frequency Plasmons in metallic Meso-structures. Physical Review Letters. 1996;76:4773-4776. DOI: 10.1103/physrevlett.76.4773
10.Pendry JB, Holden A, Robbins D, Stewart W. Magnetism from conductors and enhanced nonlinear phenomena. IEEE Transactions on Microwave Theory and Techniques. 1999;47:2075-2084. DOI: 10.1109/22.798002
11.Marqués R, Mesa F, Martel J, Medina F. Comparative analysis of edge and broadside coupled split ring resonators for metamaterial design—Theory and experiment. IEEE Transactions on Antennas and Propagation. 2003;51:2572-2581
12.Marqués R, Baena JD, Martel J, Medina F, Falcone F, Sorolla M, et al. Novel small resonant electromagnetic particles for metamaterial and filter design. In: Proceedings of the ICEAA’03, Symposiums. Torino, Italy. 8–12 September 2003. pp. 439-442
13.Marqués R, Martel J, Mesa F, Medina F. Left-handed-media simulation and transmission of EM waves in subwavelength Split-ring-resonator-loaded metallic waveguides. Physical Review Letters. 2002;89:183901. DOI: 10.1103/physrevlett.89.183901
14.Zhu J, Eleftheriades G. A compact transmission-line metamaterial antenna with extended bandwidth. IEEE Antennas and Wireless Propagation Letters. 2008;8:295-298. DOI: 10.1109/LAWP.2008.2010722
15.Baena JD, Marqués R, Martel J, Medina F. Experimental results on metamaterial simulation using SRR-loaded waveguides. In: Proceedings of the IEEE- AP/S International Symposium on Antennas and Propagation, Columbus, OH, USA. 22–27 June 2003. pp. 106-109
16.Marques R, Martel J, Mesa F, Medina F. A new 2D isotropic left-handed metamaterial design: Theory and experiment. Microwave and Optical Technology Letters. 2002;35:405-408. DOI: 10.1002/mop.10620
17.Sabban A. Small wearable metamaterials antennas for medical systems. Applied Computational Electromagnetics Society Journal. 2016;31:434-443
18.Sabban A. Microstrip antenna arrays. In: Nasimuddin N editor. Microstrip Antennas. London, UK: InTech; November 2011. pp. 361–384. ISBN 978-953-307-247-0. Available from: http://www.intechopen.com/articles/show/title/microstripantenna-arrays
19.Sabban A. Wearable antenna measurements in vicinity of human body. Wireless Engineering and Technology. 2016;7:97-104. DOI: 10.4236/wet.2016.73010
20.Sabban A. Active compact wearable body area networks for wireless communication, medical and IOT applications. MDPI ASI, Applied System Innovation Journal. 2018;1(4):46. DOI: 10.3390/asi1040046
21.Chirwa L, Hammond P, Roy S, Cumming DRS. Electromagnetic radiation from ingested sources in the human intestine between 150 MHz and 1.2 GHz. IEEE Transactions on Biomedical Engineering. 2003;50:484-492. DOI: 10.1109/tbme.2003.809474
22.Werber D, Schwentner A, Biebl EM. Investigation of RF transmission properties of human tissues. Advances in Radio Science. 2006;4:357-360. DOI: 10.5194/ars-4-357-2006
23.Gupta B, Sankaralingam S, Dhar S. Development of wearable and implantable antennas in the last decade: A review. In: Proceedings of the 2010 10th Mediterranean Microwave Symposium, Guzelyurt, Cyprus. 25–27 August 2010. pp. 251-267
24.Thalmann T, Popovic Z, Notaros BM, Mosig JR. Investigation and design of a multi-band wearable antenna. In: Proceedings of the 3rd European Conference on Antennas and Propagation, EuCAP 2009, Berlin, Germany. 23–27 March 2009. pp. 462-465
25.Salonen P, Rahmat-Samii Y, Kivikoski M. Wearable antennas in the vicinity of human body. In: Proceedings of the IEEE Antennas and Propagation Society Symposium, Monterey, CA. 20–25 June 2004. pp. 467-470
26.Kellomäki T, Heikkinen J, Kivikoski M. Wearable antennas for FM reception. In: Proceedings of the 2006 First European Conference on Antennas and Propagation, Nice, France, 6–10 November. 2006. pp. 1-6
27.Lee Y. Antenna Circuit Design for RFID Applications; Microchip (Application Note 710c). Chandler, AZ, USA: Microchip Technology Inc.; 2003
28.Sabban A. Microstrip Antenna and Antenna Arrays. U.S. Patent US 4,623,893. 18 November 1986
29.Wheeler HA. Small antennas. IEEE Transactions on Antennas and Propagation. 1975;23:462-469
30.Jamil F, Ahmad S, Iqbal N, Kim D. Towards a remote monitoring of patient vital signs based on IoT-based Blockchain integrity management platforms in smart hospitals. Sensors. 2020;20:2195. DOI: 10.3390/s20082195
31.Jamil F, Iqbal MA, Amin R, Kim D. Adaptive thermal-aware routing protocol for wireless body area network. Electronics. 2019;8:47. DOI: 10.3390/electronics8010047
32.Shahbazi Z, Byun Y-C. Towards a secure thermal-energy aware routing protocol in wireless body area network based on Blockchain technology. Sensors. 2020;20:3604. DOI: 10.3390/s20123604
33.Lin J, Itoh T. Active integrated antennas. IEEE Transactions on Microwave Theory and Techniques. 1994;42:2186-2194. DOI: 10.1109/22.339741
34.Mortazwi A, Itoh T, Harvey J. Active Antennas and Quasi-Optical Arrays. New York, NY, USA: John Wiley & Sons; 1998
35.Jacobsen S, Klemetsen Ø. Improved detectability in medical microwave radio-thermometers as obtained by active antennas. IEEE Transactions on Biomedical Engineering. 2008;55:2778-2785. DOI: 10.1109/tbme.2008.2002156
36.Jacobsen S, Klemetsen O. Active antennas in medical microwave radiometry. Electronics Letters. 2007;43:606. DOI: 10.1049/el:20070577
37.Ellingson SW, Simonetti JH, Patterson CD. Design and evaluation of an active antenna for a 29–47 MHz radio telescope array. IEEE Transactions on Antennas and Propagation. 2007;55:826-831
38.Segovia-Vargas D, Castro-Galan D, Munoz LEG, González-Posadas V. Broadband active receiving patch with resistive equalization. IEEE Transactions on Microwave Theory and Techniques. 2008;56:56-64. DOI: 10.1109/TMTT.2007.912008
39.Rizzoli V, Costanzo A, Spadoni P. Computer-aided Design of Ultra-Wideband Active Antennas by means of a new figure of merit. IEEE Microwave and Wireless Components Letters. 2008;18:290-292. DOI: 10.1109/LMWC.2008.918971
40.Sabban A. A new wideband stacked microstrip antenna. In: Proceedings of the IEEE Antenna and Propagation Symposium. Houston, TX, USA: IEEE; May 1983. pp. 23-26
41.Sabban A. Dual Polarized Dipole Wearable Antenna. U.S Patent 8203497. 19 June 2012
42.ADS Momentum Software, Keysightt. Available from: http://www.keysight.com/en/pc-1297113/advanced-design-system- ads?cc=IL&lc=eng [accessed on 3 January 2018]
43.Sabban A. New wideband printed antennas for medical applications. IEEE Transactions on Antennas and Propagation. 2013;2013(61):84-91. DOI: 10.1109/tap.2012.2214993., January
44.Paradiso JA, Starner T. Energy scavenging for mobile and wireless electronics. IEEE Pervasive Computing. 2005;4(1):18-27
45.Valenta CR, Durgin GD. Harvesting wireless power: Survey of energy-harvester conversion efficiency in far-field, wireless power transfer systems. IEEE Microwave Magazine. 2014;15(4):108-120
46.Nintanavongsa P, Muncuk U, Lewis DR, Chowdhury KR. Design optimization and implementation for RF energy harvesting circuits. IEEE Journal on Emerging and Selected Topics in Circuits and Systems. 2012;2(1):24-33
47.Devi KKA, Sadasivam S, Din NM, Chakrabarthy CK. Design of a 377 Ω patch antenna for ambient RF energy harvesting at downlink frequency of GSM 900. In: Proceedings of the 17th Asia Pacific Conference on Communications (APCC’11), Sabah, Malaysia. October 2011. pp. 492-495
Written By
Albert Sabban
Submitted: 08 December 2022Reviewed: 27 June 2023Published: 29 July 2023
Open access peer-reviewed chapter
