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Electromagnetic Shielding for RF and Microwave Packages

Abstract:

Antennas and electromagnetic radiation helped mankind to invent radio, TV, GPS, wireless communication, and many other advanced and convenient technologies that are taken for granted in our daily life. Just for a moment, imagine the world without radiation phenomena, a world without antennas and wireless communication. It would be a world without cellphones, TVs, radios, radar and satellite communication to assist in navigating the sky and oceans, a world in the 1800s. Intentional radiation is necessary to make mobile communication possible; how- ever, unintentional radiation is an obstacle to wireless and wired communications, destructive to electronic systems, and harmful to health.

Electromagnetic radiation has been increasing with every new wired and wire- less device introduced to the marketplace. The main sources for the electromagnetic radiation broadcasted from the indoor or outdoor electronic devices are intentional and unintentional waves and noises. Many devices such as cordless and wireless phones, printers, computers, internet of things (IoT)/wearable devices, remote carriage door openers, automotive electronics, base-stations antennas, and other electronics devices emit noise from residencies, workplaces, streets, shopping places, underground subways, and even from airplanes in the sky. Some pundits call the electromagnetic radiations electronic pollution since they are man-made and not normal to natural habitats. Dr. Magda Havas explained that biological effects of radio frequency radiation have been documented and range from cancers to cognitive disorders and sleeping dysfunction among humans, and abnormal behavior, reduced milk yield, miscarriages, and premature deaths among farm animals. The effects of electromagnetic radiation on human and other biological systems depend both upon the radiation’s intensity, duration, and its frequency range. North American, European, and most Asian electromagnetic compliance com- missions’ efforts focus on ensuring that electromagnetic compliant products utilizing the latest technologies are safe for consumers and the environment. This involves the entire lifecycle of products in the marketplace. RF, microwave, and digital engineers’ task is to eliminate or minimize all unintentional radiations from electronic devices and components.

Electromagnetic waves propagate through different media, including free space in the radiation mode. Radiation problems can be categorized into two subcategories: emission, and susceptibility.

Emission pertains to radiated energy and noise generated by electronic components and systems, imposed on other components, systems and external environment. Susceptibility refers to the sensitivity of electronic components and systems to externally generated electromagnetic noise. This chapter primarily explores solutions to shield RF packages from electromagnetic emissions and minimize the impact of the external noise on the internal electronic circuit elements.