Open access
Institute of Electrical and Electronics Engineers (IEEE) frequency spectrum.
1. Introduction
Owing to the rapid development of microwave technology, the microwave components and devices are increasingly common and relative low price compared to 10 years ago. Nowadays, microwave devices are often used and become an indispensable necessity in our daily routines, such as microwave ovens, mobile phones, and Internet. This introductory chapter reviews the microwave applications in this era based on a detailed literature survey and author’s experience in microwave researches.
Radio waves and microwaves are a form of electromagnetic radiation with operating frequencies ranging from 30 to 300 MHz and 300 MHz to 300 GHz, respectively [1]. Different microwave applications and technologies will use certain frequency band to avoid frequency interference. These frequencies are grouped into several smaller bands. The most commonly used frequency spectrum classification today is created by the Institute of Electrical and Electronics Engineers (IEEE), which is listed in Table 1. Microwave applications for heating and crushing normally use high microwave power which is up to megawatts. In contrast, low microwave power (less than milliwatts) is widely used for domestic wireless communication or high-frequency electronic devices. Microwave applications can be categorized into two groups, namely, communication and noncommunication. Industrial, scientific, and medical (ISM) applications are normally classified as noncommunication group. Several scopes of microwave applications are listed in Table 2. The first three industrial, scientific, and medical (ISM) frequency allocations (at 13.66 MHz, 27.32 MHz, and 40.98 MHz) were designated by US Federal Communications Commission (FCC) in 1945 [2]. Recently, there are two microwave frequencies allocated by the FCC for ISM usage, namely, 915 MHz and 2.45 GHz.
| Electromagnetic wave spectrum | Frequency band | Wavelength |
|---|---|---|
| P band (230 MHz–1 GHz) | 130–30 cm | |
| L band (1–2 GHz) | 30–15 cm | |
| S band (2–4 GHz) | 15–7.5 cm | |
| S band (2–4 GHz) | 15–7.5 cm | |
| C band (4–8 GHz) | 7.5–3.75 cm | |
| X band (8–12.5 GHz) | 3.75–2.4 cm | |
| Ku band (12.5–18 GHz) | 2.4–1.67 cm | |
| K band (18–26.5 GHz) | 1.67–1.13 cm | |
| Ka band (26.5–40 GHz) | 1.13–0.75 cm | |
| Ka band (26.5–40 GHz) | 1.13–0.75 cm | |
| V band (40–75 GHz) | 7.5–4 mm | |
| W band (75–110 GHz) | 4–2.73 mm | |
| Millimeter band (110–300 GHz) | 2.73–1 mm |
Table 1.
| Communication [3, 4, 5, 6, 7, 8] | Noncommunication [9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26] | ||
|---|---|---|---|
| 1 | Communication network systems, such as high-speed home and business networking devices (modem and router), device-to-device communication (D2D) system, massive MIMO technology, cloud technologies, and small cell access points | 1 | Sensors for industrial, agricultural/food, and medical processing, such as moisture measurement, ripeness/storage period determination, fruit sweetness detection, control of milk of lime, monitoring of nitrogen/phosphorus content in fertilizer, medical diagnostic, moisture soil testing, metal crack detector, and storage tank measurement devices |
| 2 | Communication devices and test instruments, such as spectrum analyzer, RF power meter, frequency counter, signal generator, and vector network analyzer | 2 | Heating/drying or freeze-drying process (sterilization /pasteurization) in food industry to control pathogenic and spoilage microorganisms in packaged foods |
| 3 | Navigation systems such as maritime navigation, Global Positioning System (GPS), air traffic control, airborne radars, and satellite communication | 3 | Industrial heating applications, such as casting waxes, sintering ceramics/metal powders, melting of glass/rubber, metal coating, brazing, and paper/wood drying |
| 4 | Wireless remote control for security and healthcare systems such as automatic gate/door, automatic barrier systems, burglar alarms, and industrial automation systems (Industry 4.0) | 4 | Medical applications, such as hyperthermia treatments, bio-impedance instrumentation, and medical diagnostic imaging (to detect a location or movement of objects within a human body or animal body) |
| 5 | Vehicular radar systems to detect the location and movement of objects near a vehicle, enabling features such as near collision avoidance, improved airbag activation, and suspension systems that better respond to road conditions | 5 | Material characterization fixtures (materials including graphene, metamaterials, carbon nanotube, conductive polymer, high-temperature superconductor, aerogel, ceramics, semiconductor, polymer insulation, fibers, gases, and chemical liquids) |
| 6 | Entertainment and information communication devices/systems such as television broadcast, FM broadcast, radio beacons, maritime radio, walkie-talkie, coast guard communication, satellite communication, and weather radars | 6 | Image scan systems to detect the images of buried objects, location of objects contained within a wall, location or movement of persons or objects which are located on the other side of a wall, as well as the intrusion of persons |
| 7 | Domestic communication devices, such as 4G/5G smart phone, computer, Bluetooth, Wi-Fi devices, wireless webcam, and wireless microphones | 7 | Civil engineering applications (rock crushing, tar road comminuting) |
| 8 | Radiation for agricultural pest control | ||
Table 2.
Microwave applications for communication and noncommunication technologies.
Currently, most of the applications are devoted to the 2.45 GHz point, since it provides a suitable compromise between power deposition and penetration depth. The ISM bands defined by the International Telecommunication Union (ITU) are listed in Table 3 [1]. However, during recent years, ISM bands have also been shared with license-free error-tolerant communications applications, such as wireless LANs. In addition, now is the era of the fourth industrial revolution, so-called Industry 4.0, which most operation systems in the industry are in cyber based. Hence, the combination between communication (Internet) and noncommunication (microwave things) technologies is increasingly popular in order to produce smart devices, so-called Internet of Things (IoT), in which the devices are embedded with electronics, software, sensors, actuators, and network connectivity that are capable of covering a variety of protocols, domains, and applications, which include the automotive industry, public safety, emergency services, and medical field [3].
| Frequency range ( | Bandwidth (Δ | Center frequency ( | |
|---|---|---|---|
| MHz | *6.765–6.795 MHz | *30 kHz | *6.780 MHz |
| 13.553–13.567 MHz | 14 kHz | 13.560 MHz | |
| 26.957–27.283 MHz | 326 kHz | 27.120 MHz | |
| 40.660–40.700 MHz | 40 kHz | 40.680 MHz | |
| **433.050–434.790 MHz | *1.74 MHz | *433.920 MHz | |
| ***902.000–928.000 MHz | *26 MHz | *915.000 MHz | |
| GHz | 2.400–2.500 GHz | 100 MHz | 2.450 GHz |
| 5.725–5.875 GHz | 150 MHz | 5.800 GHz | |
| 24.000–24.250 GHz | 250 MHz | 24.125 GHz | |
| *26.975–27.283 GHz | *308 MHz | *27.129 GHz | |
| *61.000–61.500 GHz | *500 MHz | *61.250 GHz | |
| *122.000–123.000 GHz | *1 GHz | *122.500 GHz | |
| *244.000–246.000 GHz | *2 GHz | *245.000 GHz | |
Table 3.
Industrial, scientific, and medical (ISM) operating frequency band defined by the International Telecommunication Union (ITU).
Subject to local acceptance
Only Europe, Africa, the Middle East/Middle West of the Persian Gulf, the former Soviet Union, and Mongolia
Only Americas, Greenland, and some of the eastern Pacific Islands
Within the past 40 years, microwave technology using frequency operation exceeding 300 GHz to 3 THz also existed, so-called Terahertz technology. In fact, operating frequency of 300 GHz to 3 THz occupies a middle ground between microwaves and infrared light waves. The corresponding range of the wavelength for the Terahertz frequencies is 0.1–1 mm; thus, it is a denominated submillimeter wave [27]. The Terahertz technology is widely utilized in the field of astronomy, medical, and security, such as space-based remote sensing and medical diagnostic imaging [28, 29, 30, 31], due to the submillimeter waves that are nonionizing, and it can penetrate a wide variety of nonconducting materials. Recently, high operating frequency requirements for microwave test instruments are increasing, such as recent commercial vector network analyzer which is capable of achieving 1.1 THz. Hence, in future, these microwave components and devices are expected to be very small and sensitive.
References
- 1.
You KY. RF Coaxial Slot Radiators: Modeling, Measurements, and Applications. USA: Artech House; 2015. ISBN: 978-1-60807-822-6 - 2.
Osepchuk JM. A history of microwave heating applications. IEEE Transactions on Microwave Theory and Techniques. 1984; 32 (9):1200-1224. DOI: 10.1109/TMTT.1984.1132831 - 3.
Riazul Islam SM, Kwak D, Humaun Kabir MD, Hossain M, Kwak KS. The Internet of Things for health care: A comprehensive survey. IEEE Access. 2015; 3 :678-708. DOI: 10.1109/ACCESS.2015.2437951 - 4.
Sobol H. Microwave communications—An historical perspective. IEEE Transactions on Microwave Theory and Techniques. 1984; 32 (9):1170-1181. DOI: 10.1109/TMTT.1984.1132829 - 5.
Gresham I, Jenkins A, Egri R, Eswarappa C, Kinayman N, Jain N, Anderson R, Kolak F, Wohlert R, Bawell SP, Bennett J, Lanteri J-P. Ultra-wideband radar sensors for short-range vehicular applications. IEEE Transactions on Microwave Theory and Techniques. 2004; 52 (9):2105-2122. DOI: 10.1109/TMTT.2004.834185 - 6.
Draganov S, Harlacher M, Haas L, Wenske M, Schneider C. Synthetic aperture navigation in multipath environments. IEEE Wireless Communications. 2011; 18 (2):52-58. DOI: 10.1109/MWC.2011.5751296 - 7.
Wang W-Q, Jiang D. Integrated wireless sensor systems via near-space and satellite platforms: A review. IEEE Sensors Journal. 2014; 14 (11):3903-3914. DOI: 10.1109/JSEN.2014.2356580 - 8.
Gupta A, Rakesh Kumar JHA. A survey of 5G network: Architecture and emerging technologies. IEEE Access. 2015; 3 :1206-1232. DOI: 10.1109/ACCESS.2015.2437951 - 9.
Zhang H, Yang R, Foudazi A, Cheng L, Tian G. A review of microwave thermography nondestructive testing and evaluation. Sensors. 2017; 17 (1123):1-33. DOI: 10.3390/s17051123 - 10.
Berthold Technologies. Concentration Measurements for Milk of Lime: Microwave Measurement. Food-Sugar Production Manual. Retrieved on June 6, 2017. Available from: https://www.berthold.com/en/system/asset/application_milk_of_lime_measurment.pdf - 11.
Berthold Technologies. Moisture Measurement on Bales of Lucerne, Tobacco and Others. Microwave Application Manual. Retrieved on June 6, 2017. Available from: https://www.berthold.com/en/pc/downloads - 12.
Hydronix. New moisture management technology by Hydronix. Industry Manual. April 2010. Retrieved on August 31, 2017. Available from: https://www.hydronix.com/downloads/articles/product_range/new_moisture_management_technology_for_grain.pdf - 13.
George M. Microwave moisture measurement. Grain & Feed Milling Technology. 2008; 119 :14-16 - 14.
Rezaei M, Ebrahimi E, Naseh S, Mohajerpour M. A new 1.4 GHz soil moisture sensor. Measurement. 2012; 45 (2012):1723-1728. DOI: 10.1016/j.measurement.2012.04.014 - 15.
Singh S, Gupta D, Jain V, Apurbba K. Sharma: Microwave processing of materials and applications in manufacturing industries: A review. Materials and Manufacturing Processes. 2015; 30 :1-29. DOI: 10.1080/10426914.2014.952028 - 16.
Okamura S, Zhang Y, Tsukamoto N. A new microstrip line-type moisture sensor for heavily wet tea leaves. Measurement Science and Technology. 2007; 18 :1022-1028. DOI: 10.1080/10426914.2014.952028 - 17.
Nelson S. Dielectric Properties of Agricultural Materials and their Applications; USA: Academic Press. 2015. ISBN: 9780128023051 - 18.
You KY, You LL, Yue CS, Mun HK, Lee CY. Chapter 6. Physical and chemical characterization of rice using laboratory and microwave methods. In: Rice—Technology and Production, Edit by Amanullah and Shah Fahad. USA: InTech; 2017. pp. 81-99. ISBN: 978-953-51-5200-2 - 19.
You KY. Chapter 14 Materials Characterization Using Microwave Waveguide Systems. In: Goudos SK, editor. Microwave Systems and Applications. USA: InTech; 2017. pp. 341-358. ISBN: 978-953-51-2867-0 - 20.
You KY, Then YL. Simple calibration and dielectric measurement technique for thin material using coaxial probe. IEEE Sensors Journal. 2015; 15 (10):5393-5397. DOI: 10.1109/JSEN.2015.2427873 - 21.
You KY, Lee YS, Zahid L, MFA M, Lee KY, Cheng EM. Dielectric measurements for low-loss materials using transmission phase-shift method. Jurnal Teknologi. 2015; 77 (10):69-77. DOI: 10.11113/jt.v77.6286 - 22.
Mason A, Korostynska O, Louis J, Cordova-Lopez LE, Abdullah B, Greene J, Connell R, Hopkins J. Non-invasive in-situ measurement of blood lactate using microwave sensors. IEEE Transactions on Biomedical Engineering. 2017. DOI: 10.1109/TBME.2017.2715071 - 23.
Choi H, Naylon J, Luzio S, Beutler J, Birchall J, Martin C, Porch A. Design and in vitro interference test of microwave noninvasive blood glucose monitoring sensor. IEEE Transactions on Microwave Theory and Techniques. 2015; 63 (10):3016-3025. DOI: 10.1109/TMTT.2015.2472019 - 24.
Nguyen PT, Abbosh A, Crozier S. Three-dimensional focused microwave hyperthermia for breast cancer treatment with experimental validation. IEEE Transactions on Antennas and Propagation. 2017; 65 (7):3489-3500. DOI: 10.1109/TAP.2017.2700164 - 25.
Shultz K, Stang P, Kerr A, Pauly J, Scott G. RF field visualization of RF ablation at the Larmor frequency. IEEE Transactions on Medical Imaging. 2012; 31 (4):938-947. DOI: 10.1109/TMI.2011.2162248 - 26.
Zhang X, Liu J, He B. Magnetic-resonance-based electrical properties tomography: A review. IEEE Reviews in Biomedical Engineering. 2014; 7 :87-96. DOI: 10.1109/RBME.2013.2297206 - 27.
Wiltse JC. History of millimeter and submillimeter waves. IEEE Transactions on Microwave Theory and Techniques. 1984; 32 (9):1118-1127. DOI: 10.1109/TMTT.1984.1132823 - 28.
Siegel PH. Terahertz technology. IEEE Transactions on Microwave Theory and Techniques. 2002; 50 (3):910-928. DOI: 10.1109/22.989974 - 29.
Chattopadhyay G. Technology, capabilities, and performance of low power Terahertz sources. IEEE Transactions on Terahertz Science and Technology. 2011; 1 (1):33-53. DOI: 10.1109/TTHZ.2011.2159561 - 30.
Ke W, Jian Cheng Y, Djerafi T, Hong W. Substrate-integrated millimeter-wave and terahertz antenna technology. Proceedings of the IEEE. 2012; 100 (7):2219-2232. DOI: 10.1109/JPROC.2012.2190252 - 31.
Tabata H. Application of terahertz wave technology in the biomedical field. IEEE Transactions on Terahertz Science and Technology. 2015; 5 (6):1146-1153