The International Amateur Radio Union ( IARU ) is an international confederation of national organisations that allows a forum for common matters of concern to amateur radio operators worldwide, and collectively represents matters to the International Telecommunication Union (ITU). The International Amateur Radio Union was founded in 1925 and, as of July 2021, it is composed of 172 national member societies.
49-402: IARU may refer to: International Amateur Radio Union International Alliance of Research Universities Irish Amateur Rowing Union - former title of Rowing Ireland An alternative spelling for Aaru in ancient Egyptian mythology Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with
98-405: A parabolic antenna or a diversity receiver , can be used to select one signal in space to the exclusion of others. The most extreme example of digital spread-spectrum signalling to date is ultra-wideband ( UWB ), which proposes the use of large sections of the radio spectrum at low amplitudes to transmit high-bandwidth digital data. UWB, if used exclusively, would enable very efficient use of
147-650: A "shimmy" effect in each other, due to the electromagnetic nature of their picture tubes, especially when one of their de-gaussing coils is activated. Electromagnetic interference at 2.4 GHz may be caused by 802.11b , 802.11g and 802.11n wireless devices, Bluetooth devices, baby monitors and cordless telephones , video senders , and microwave ovens . Switching loads ( inductive , capacitive , and resistive ), such as electric motors, transformers, heaters, lamps, ballast, power supplies, etc., all cause electromagnetic interference especially at currents above 2 A . The usual method used for suppressing EMI
196-656: A President, Vice-President, Secretary, Treasurer, and several Directors. These regional officers are elected by representatives from the member societies at triennial regional conferences. Coordinators may be appointed by the Executive Committee of their region to support particular areas within the region, or to promote certain amateur radio activities within the region. All three regions have appointed Coordinators for Amateur Radio Direction Finding , emergency communications , monitoring for electromagnetic interference , and radio propagation . IARU Region 1 includes
245-536: A barrier to trade within the EC. One of these was the EMC Directive (89/336/EC) and it applies to all equipment placed on the market or taken into service. Its scope covers all apparatus "liable to cause electromagnetic disturbance or the performance of which is liable to be affected by such disturbance". This was the first time there was a legal requirement on immunity, as well as emissions on apparatus intended for
294-634: A combination of emissions , radiations , or inductions upon reception in a radiocommunication system, manifested by any performance degradation, misinterpretation, or loss of information which could be extracted in the absence of such unwanted energy". This is also a definition used by the frequency administration to provide frequency assignments and assignment of frequency channels to radio stations or systems, as well as to analyze electromagnetic compatibility between radiocommunication services . In accordance with ITU RR (article 1) variations of interference are classified as follows: Conducted EMI
343-643: A detector for those radio signals commonly found in the domestic environment (e.g. mobile phones). Such a detector can demodulate the high frequency mobile phone carrier (e.g., GSM850 and GSM1900, GSM900 and GSM1800) and produce low-frequency (e.g., 217 Hz) demodulated signals. This demodulation manifests itself as unwanted audible buzz in audio appliances such as microphone amplifier, speaker amplifier, car radio, telephones etc. Adding onboard EMI filters or special layout techniques can help in bypassing EMI or improving RF immunity. Some ICs are designed (e.g., LMV831-LMV834, MAX9724 ) to have integrated RF filters or
392-530: A radio station at its headquarters in Newington, Connecticut . Its callsign is NU1AW. As an amateur radio station licensed by the U.S. Federal Communications Commission the "1" stands for its location in the New England area. "NU" was taken from the pre-1928 era when amateurs made up their own prefixes, and informally used these letters to show they were in "North America—USA". The "AW" suffix represents
441-402: A special design that helps reduce any demodulation of high-frequency carrier. Designers often need to carry out special tests for RF immunity of parts to be used in a system. These tests are often done in an anechoic chamber with a controlled RF environment where the test vectors produce a RF field similar to that produced in an actual environment. Interference in radio astronomy , where it
490-436: A wavelength apart, inducing a change in voltage on the receiving conductor. Inductive coupling or magnetic coupling occurs when a varying magnetic field exists between two parallel conductors typically less than a wavelength apart, inducing a change in voltage along the receiving conductor. Radiative coupling or electromagnetic coupling occurs when source and victim are separated by a large distance, typically more than
539-625: A wavelength. Source and victim act as radio antennas: the source emits or radiates an electromagnetic wave which propagates across the space in between and is picked up or received by the victim. Interference with the meaning of electromagnetic interference , also radio-frequency interference ( EMI or RFI ) is – according to Article 1.166 of the International Telecommunication Union ' s (ITU) Radio Regulations (RR) – defined as "The effect of unwanted energy due to one or
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#1732801481719588-621: Is a committee of the International Electrotechnical Commission (IEC) sets international standards for radiated and conducted electromagnetic interference. These are civilian standards for domestic, commercial, industrial and automotive sectors. These standards form the basis of other national or regional standards, most notably the European Norms (EN) written by CENELEC (European committee for electrotechnical standardisation). US organizations include
637-452: Is as good as the other) and the length of the conductor in relation to the wavelength of the signal component ( fundamental frequency , harmonic or transient such as overshoot, undershoot or ringing). At lower frequencies, such as 133 MHz , radiation is almost exclusively via I/O cables; RF noise gets onto the power planes and is coupled to the line drivers via the VCC and GND pins. The RF
686-400: Is by connecting a snubber network, a resistor in series with a capacitor , across a pair of contacts. While this may offer modest EMI reduction at very low currents, snubbers do not work at currents over 2 A with electromechanical contacts. Another method for suppressing EMI is the use of ferrite core noise suppressors (or ferrite beads ), which are inexpensive and which clip on to
735-509: Is caused by the physical contact of the conductors as opposed to radiated EMI which is caused by induction (without physical contact of the conductors). For lower frequencies, EMI is caused by conduction and, for higher frequencies, by radiation. EMI through the ground wire is also very common in an electrical facility. Interference tends to be more troublesome with older radio technologies such as analogue amplitude modulation , which have no way of distinguishing unwanted in-band signals from
784-532: Is caused by the physical contact of the conductors as opposed to radiated EMI, which is caused by induction (without physical contact of the conductors). Electromagnetic disturbances in the EM field of a conductor will no longer be confined to the surface of the conductor and will radiate away from it. This persists in all conductors and mutual inductance between two radiated electromagnetic fields will result in EMI. Some of
833-457: Is commonly referred to as radio-frequency interference (RFI), is any source of transmission that is within the observed frequency band other than the celestial sources themselves. Because transmitters on and around the Earth can be many times stronger than the astronomical signal of interest, RFI is a major concern for performing radio astronomy. Natural sources of interference, such as lightning and
882-593: Is into narrowband and broadband, according to the spread of the frequency range. An electromagnetic pulse (EMP), sometimes called a transient disturbance, arises where the source emits a short-duration pulse of energy. The energy is usually broadband by nature, although it often excites a relatively narrow-band damped sine wave response in the victim. Sources divide broadly into isolated and repetitive events. Sources of isolated EMP events include: Sources of repetitive EMP events, sometimes as regular pulse trains , include: Conducted electromagnetic interference
931-664: Is operated by a member society after election by members. Currently, the American Radio Relay League (ARRL) operates the IARUIS from its headquarters in Newington, Connecticut , US. The IARU is organised into three regions, named Region 1, Region 2, and Region 3. These regions correspond to the regulatory regions used by the International Telecommunication Union . Each region has an Executive Committee, typically composed of
980-483: Is then coupled to the cable through the line driver as common-mode noise . Since the noise is common-mode, shielding has very little effect, even with differential pairs . The RF energy is capacitively coupled from the signal pair to the shield and the shield itself does the radiating. One cure for this is to use a braid-breaker or choke to reduce the common-mode signal. At higher frequencies, usually above 500 MHz, traces get electrically longer and higher above
1029-837: The Radio Society of Great Britain are full member societies of IARU Region 3. The ARRL represents amateur radio operators in American Samoa , Guam , the Northern Marianas , and other dependent territories in the Pacific Ocean . The RSGB represents amateur radio operators in the British Indian Ocean Territory . IARU Region 3 has a special emphasis on promoting the harmonization of license qualifications in an effort to promote easier reciprocal operations by amateur radio operators in
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#17328014817191078-783: The United States , a plan was formulated to hold an International Amateur Congress in Paris , France, in April 1925. This Congress was held for the purpose of founding an international amateur radio organization. The Congress was attended by representatives of 23 countries in Europe , Americas , and Asia . A constitution for the IARU was adopted on April 17, and the formation of the International Amateur Radio Union
1127-897: The radio frequency spectrum, is a disturbance generated by an external source that affects an electrical circuit by electromagnetic induction , electrostatic coupling , or conduction. The disturbance may degrade the performance of the circuit or even stop it from functioning. In the case of a data path, these effects can range from an increase in error rate to a total loss of the data. Both human-made and natural sources generate changing electrical currents and voltages that can cause EMI: ignition systems , cellular network of mobile phones, lightning , solar flares , and auroras (northern/southern lights). EMI frequently affects AM radios . It can also affect mobile phones , FM radios , and televisions , as well as observations for radio astronomy and atmospheric science . EMI can be used intentionally for radio jamming , as in electronic warfare . Since
1176-545: The 21st century by roughly one decibel per year as the spectrum becomes increasingly crowded. This has inflicted a Red Queen's race on the mobile phone industry as companies have been forced to put up more cellular towers (at new frequencies) that then cause more interference thereby requiring more investment by the providers and frequent upgrades of mobile phones to match. The International Special Committee for Radio Interference or CISPR (French acronym for "Comité International Spécial des Perturbations Radioélectriques"), which
1225-685: The First Panamerican Radio Amateur Congress in Mexico City , Mexico . Antonio Pita, XE1CCP was the region's first elected president. Executive officers: IARU Region 3 includes the member societies representing amateur radio operators in Australia , most of Asia , and the Pacific Islands . Although most of their membership is located in other IARU regions, the American Radio Relay League and
1274-690: The Institute of Electrical and Electronics Engineers (IEEE), the American National Standards Institute (ANSI), and the US Military (MILSTD). Integrated circuits are often a source of EMI, but they must usually couple their energy to larger objects such as heatsinks, circuit board planes and cables to radiate significantly. On integrated circuits , important means of reducing EMI are: the use of bypass or decoupling capacitors on each active device (connected across
1323-555: The Sun, are also often referred to as RFI. Some of the frequency bands that are very important for radio astronomy, such as the 21-cm HI line at 1420 MHz, are protected by regulation. However, modern radio-astronomical observatories such as VLA , LOFAR , and ALMA have a very large bandwidth over which they can observe. Because of the limited spectral space at radio frequencies, these frequency bands cannot be completely allocated to radio astronomy; for example, redshifted images of
1372-615: The connection with the American Radio Relay League , whose own station is W1AW. NU1AW is frequently active during amateur radio contests. For many years the IARU has issued the Worked All Continents certificate to amateurs who contact fellow hams in the six permanently populated continental areas of the world. Special awards and endorsements for various bands and modes are also available. Electromagnetic interference Electromagnetic interference ( EMI ), also called radio-frequency interference ( RFI ) when in
1421-646: The earliest days of radio communications, the negative effects of interference from both intentional and unintentional transmissions have been felt and the need to manage the radio frequency spectrum became apparent. In 1933, a meeting of the International Electrotechnical Commission (IEC) in Paris recommended the International Special Committee on Radio Interference ( CISPR ) be set up to deal with
1470-497: The emerging problem of EMI. CISPR subsequently produced technical publications covering measurement and test techniques and recommended emission and immunity limits. These have evolved over the decades and form the basis of much of the world's EMC regulations today. In 1979, legal limits were imposed on electromagnetic emissions from all digital equipment by the FCC in the US in response to
1519-490: The general population. Although there may be additional costs involved for some products to give them a known level of immunity, it increases their perceived quality as they are able to co-exist with apparatus in the active EM environment of modern times and with fewer problems. Many countries now have similar requirements for products to meet some level of electromagnetic compatibility (EMC) regulation. Electromagnetic interference divides into several categories according to
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1568-485: The increased number of digital systems that were interfering with wired and radio communications. Test methods and limits were based on CISPR publications, although similar limits were already enforced in parts of Europe. In the mid 1980s, the European Union member states adopted a number of "new approach" directives with the intention of standardizing technical requirements for products so that they do not become
1617-440: The intended signal, and the omnidirectional antennas used with broadcast systems. Newer radio systems incorporate several improvements that enhance the selectivity . In digital radio systems, such as Wi-Fi , error-correction techniques can be used. Spread-spectrum and frequency-hopping techniques can be used with both analogue and digital signalling to improve resistance to interference. A highly directional receiver, such as
1666-426: The lower path in the diagram involves inductive, conductive and capacitive modes. Conductive coupling occurs when the coupling path between the source and victim is formed by direct electrical contact with a conducting body, for example a transmission line, wire, cable, PCB trace or metal enclosure. Conducted noise is also characterised by the way it appears on different conductors: Inductive coupling occurs where
1715-510: The member societies representing amateur radio operators in Africa , Europe , the Middle East , and northern Asia . IARU Region 1 has the largest number of member societies among the three IARU regions, and has been the source of several international initiatives. IARU Region 1 lobbying efforts led to the creation of the 30 meter , 17 meter , and 12 meter amateur radio bands, improving
1764-423: The plane. Two techniques are used at these frequencies: wave shaping with series resistors and embedding the traces between the two planes. If all these measures still leave too much EMI, shielding such as RF gaskets and copper or conductive tape can be used. Most digital equipment is designed with metal or conductive-coated plastic cases. Any unshielded semiconductor (e.g. an integrated circuit) will tend to act as
1813-571: The power lead of the offending device or the compromised device. Switched-mode power supplies can be a source of EMI, but have become less of a problem as design techniques have improved, such as integrated power factor correction . Most countries have legal requirements that mandate electromagnetic compatibility : electronic and electrical hardware must still work correctly when subjected to certain amounts of EMI, and should not emit EMI, which could interfere with other equipment (such as radios). Radio frequency signal quality has declined throughout
1862-422: The power supply, as close to the device as possible), rise time control of high-speed signals using series resistors, and IC power supply pin filtering. Shielding is usually a last resort after other techniques have failed, because of the added expense of shielding components such as conductive gaskets. The efficiency of the radiation depends on the height above the ground plane or power plane (at RF , one
1911-403: The region. Executive officers: * = Amateur radio licenses not issued in this country The Global Amateur Radio Emergency Communications Conference or "GAREC" is a yearly conference held by the International Amateur Radio Union for discussion of amateur radio operation during natural disasters and other emergencies with the motto, "Saving lives through emergency communications". GAREC
1960-445: The source and signal characteristics. The origin of interference, often called "noise" in this context, can be human-made (artificial) or natural. Continuous, or continuous wave (CW), interference arises where the source continuously emits at a given range of frequencies. This type is naturally divided into sub-categories according to frequency range, and as a whole is sometimes referred to as "DC to daylight". One common classification
2009-437: The source and victim are separated by a short distance (typically less than a wavelength ). Strictly, "Inductive coupling" can be of two kinds, electrical induction and magnetic induction. It is common to refer to electrical induction as capacitive coupling , and to magnetic induction as inductive coupling . Capacitive coupling occurs when a varying electrical field exists between two adjacent conductors typically less than
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2058-510: The source may be a natural phenomenon such as a lightning strike , electrostatic discharge (ESD) or, in one famous case , the Big Bang at the origin of the Universe. There are four basic coupling mechanisms: conductive , capacitive , magnetic or inductive, and radiative . Any coupling path can be broken down into one or more of these coupling mechanisms working together. For example
2107-859: The spectrum, but users of non-UWB technology are not yet prepared to share the spectrum with the new system because of the interference it would cause to their receivers (the regulatory implications of UWB are discussed in the ultra-wideband article). In the United States , the 1982 Public Law 97-259 allowed the Federal Communications Commission (FCC) to regulate the susceptibility of consumer electronic equipment. Potential sources of RFI and EMI include: various types of transmitters , doorbell transformers, toaster ovens , electric blankets , ultrasonic pest control devices, electric bug zappers , heating pads , and touch controlled lamps . Multiple CRT computer monitors or televisions sitting too close to one another can sometimes cause
2156-597: The standardization of reciprocal licensing , promoting Amateur Radio Direction Finding and initiating youth related activities, known as "the Youngsters On the Air project" (YOTA) Executive officers: IARU Region 2 includes the member societies representing amateur radio operators in the Americas . The organization of IARU Region 2 was founded in 1964 when representatives from 15 national radio societies attended
2205-449: The technical terms which are employed can be used with differing meanings. Some phenomena may be referred to by various different terms. These terms are used here in a widely accepted way, which is consistent with other articles in the encyclopedia. The basic arrangement of noise emitter or source, coupling path and victim, receptor or sink is shown in the figure below. Source and victim are usually electronic hardware devices, though
2254-620: The title IARU . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=IARU&oldid=932885729 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages International Amateur Radio Union Following an informal meeting in 1924 of representatives from France , Great Britain , Belgium , Switzerland , Italy , Spain , Luxembourg , Canada , and
2303-528: The world. The IARU promulgates the rules used for high-speed telegraphy and sponsors regional and world championships. The IARU also promulgates the rules used by most competitions in amateur radio direction finding , including IARU-sponsored regional and world championships. The IARU also sponsors the annual IARU HF World Championship in amateur radio contesting . The IARU does not directly administer any of these radiosport events, but authorises and sponsors them through host organisations. The IARU maintains
2352-594: Was first held in Tampere, Finland in 2005, coinciding with the adoption of the Tampere Convention , a globally binding emergency communications treaty that had been signed in Tampere in 1998. In later conferences, the venue has attempted to rotate in sequence through ITU Regions 1, 2 and 3 (though not necessarily in that particular order). The IARU organises and promotes radiosport activities throughout
2401-660: Was ratified on April 18, 1925. In the current era, this is the date (April 18) on which World Amateur Radio Day is celebrated. The protocol of the congress was written in English, French and Esperanto . The IARU has an elected President and Vice President, an appointed Secretary and other officials (including regional representatives) forming an Administrative Council. These office holders are presently Timothy Ellam, VE6SH (Canada), President; Ole Garpestad, LA2RR (Norway), Vice-President; and Joel Harrison, W5ZN (United States), Secretary. The IARU International Secretariat (IARUIS)
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