{"id":120222,"date":"2026-11-03T07:30:00","date_gmt":"2026-11-03T06:30:00","guid":{"rendered":"https:\/\/www.reichelt.com\/magazin\/?p=120222"},"modified":"2026-11-03T13:39:29","modified_gmt":"2026-11-03T12:39:29","slug":"those-who-understand-rf-technology-today-are-ready-for-6g-tomorrow","status":"publish","type":"post","link":"https:\/\/www.reichelt.com\/magazin\/en\/guide\/those-who-understand-rf-technology-today-are-ready-for-6g-tomorrow\/","title":{"rendered":"Those Who Understand RF Technology Today Are Ready for 6G Tomorrow"},"content":{"rendered":"\n

High-frequency technology (HF technology) is used in almost everything nowadays: Wi-Fi, Bluetooth, mobile communications, navigation systems and countless Internet of Things (IoT) devices all use high-frequency signals. Understanding how these signals are generated, transmitted, received and measured provides insight into the inner workings of modern wireless technology and enables more effective selection and deployment of antennas, radio modules and circuits.<\/p>\n\n\n\n

Development is ongoing: the next generation of mobile communications, 6G, is already on the horizon. Much of this is still a long way off, but topics such as higher frequencies, smart antenna systems, AI-supported networks and new applications \u2014 from precise positioning to holographic communication \u2014 demonstrate where this journey may lead. The technical foundations for this are already being laid today.<\/p>\n\n\n\n

This guide covers the key fundamentals of RF technology, explains the role of antennas and EMC, and highlights the crucial components and tools in practice. It is ideal for makers, students, and anyone who wants to better understand today’s wireless technology and prepare for tomorrow’s technologies.<\/p>\n\n\n\n

Fundamentals of Radio Frequency Technology<\/h2>\n\n\n\n
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From Frequency to Antenna Length<\/strong><\/p>\n\n\n\n

Two quantities are particularly important: frequency and wavelength<\/strong>. Frequency describes how often a signal oscillates per second. Wavelength is the distance between two identical points on a wave; for example, between two wave crests.<\/p>\n\n\n\n

These two quantities are related via the speed of propagation of electromagnetic waves:
\u03bb = c \/ f<\/strong>

As a rule of thumb:<\/strong>
The wavelength in metres is approximately equal to 300 divided by the frequency in megahertz:
300 \/ frequency (MHz) = wavelength (m)<\/strong><\/p>\n\n\n\n

At 2.4 GHz (i.e. 2,400 MHz), this gives: 300 \/ 2400 = 0,125 m<\/strong>

The wavelength is therefore around 12.5 cm. An ideal quarter-wave antenna would therefore be about 3.1 cm long.<\/p>\n<\/div><\/div>\n\n\n\n

In practice, however, the actual length of the antenna depends on its design, the printed circuit board, the ground plane, the housing, the environment and the materials used. Therefore, a PCB antenna, chip antenna or PIFA antenna may look significantly different from a simple wire dipole.<\/p>\n\n\n\n

As frequency increases, antennas<\/a><\/strong> become smaller. At the same time, the demands placed on PCB layout, cables, connectors and mechanical design increase. Losses in cables, connectors, walls and enclosures increase. At high frequencies, trace paths and cables no longer behave like simple connections, but rather like transmission lines with a defined impedance.<\/p>\n\n\n\n

The length, geometry, ground planes and transitions of these components directly influence the signal level, phase and quality. Short signal paths, clean ground planes, defined impedances and controlled return paths are crucial at high frequencies.<\/p>\n\n\n\n

Modulation: Information on a carrier signal<\/h3>\n\n\n\n

For information to be transmitted wirelessly, it must first be modulated onto a high-frequency carrier signal.<\/p>\n\n\n\n

In amplitude modulation, the amplitude of the carrier signal is varied. In frequency modulation, on the other hand, the carrier frequency is shifted by a centre frequency. Phase modulation involves the phase of the signal alternating between defined states.<\/p>\n\n\n\n

Modern wireless standards use digital modulation techniques. QPSK and QAM combine amplitude and phase to transmit several bits per symbol. OFDM distributes the data across many narrow subcarriers that are orthogonal to one another. This allows for better management of interference, reflections, and multipath propagation.<\/p>\n\n\n\n

Modulation determines how digital information is converted into a radio signal and recovered again.<\/p>\n\n\n\n

RF technology in a nutshell: QPSK, QAM and OFDM Explained Simply<\/strong><\/p>\n\n\n\n

Abbreviation<\/th>Term<\/th>Explained simply<\/th><\/tr><\/thead>
QPSK<\/td>Quadrature Phase Shift Keying<\/td>Uses four different phase states of a signal to transmit two bits per symbol.<\/td><\/tr>
QAM<\/td>Quadrature Amplitude Modulation<\/td>Combines different amplitudes and phases to transmit several bits per symbol. The more signal states there are, the higher the possible data rate at the same symbol rate.<\/td><\/tr>
OFDM<\/td>Orthogonal Frequency Division Multiplexing<\/td>Distributes data across many narrow subcarriers that are orthogonal to one another. This enables efficient transmission and helps to reduce the effects of multipath propagation.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Antennas and matching<\/h2>\n\n\n\n

<\/span>Antennas convert wired RF signals into electromagnetic waves, and vice versa. The design, dimensions, mounting position and environment of an antenna influence its range and signal quality.<\/p>\n\n\n\n

Common types of antenna include dipoles, monopoles, patches, helicals, PCB and chips. Antenna modules may feature various connectors, such as SMA, RP-SMA and U.FL, as well as other RF connectors. SMA is a connector system, not a type of antenna.<\/p>\n\n\n\n

An important consideration is impedance matching between the radio module, cable, connector and antenna. In many RF applications, 50 ohms is the standard system impedance. If the source, cable and antenna are not properly matched, reflections occur. This means that part of the power is reflected back instead of being radiated or transmitted.<\/p>\n\n\n\n

The matching can be assessed using the voltage standing wave ratio (VSWR), amongst other things. Values around 1.5:1 are acceptable in many applications. Significantly higher values, such as above 2:1, should be investigated.<\/p>\n\n\n\n

\"Typisches<\/a><\/figure>\n\n\n\n

Coaxial cables are also part of the system at high frequencies. The signal is influenced by factors such as length, attenuation, bend radius, connectors and adaptors. At high frequencies, cable attenuation increases. Long or thin coaxial cables can cause noticeable losses at 2.4 GHz. Therefore, short cables, suitable connectors and a neat mechanical design are important.<\/p>\n\n\n\n

Ferrite beads and EMC<\/h3>\n\n\n\n

<\/span>Not all high-frequency signals in a circuit are intentional. Fast transition edges, clock frequencies, DC\/DC converters, microcontrollers, displays, USB interfaces and radio modules can all generate high-frequency interference. This interference can propagate via power supply lines, signal lines, or ground planes.<\/p>\n\n\n\n

Ferrite beads<\/a><\/strong> are used to reduce such interference. For direct current, they behave largely like a low-impedance connection. At higher frequencies, however, their impedance increases. This enables them to reduce RF interference on lines.<\/p>\n\n\n\n

Typical applications include:<\/strong><\/p>\n\n\n\n