The lack of electromagnetic compatibility, an apparently minor concept, has resulted in the loss of helicopters at human cost or the sinking of ships in service. If an electronic device interferes with another inside, e.g. B. a fighter aircraft, does this lead to a malfunction of the course display or the radio, just like an electronic war device that sends out very complex signals, can the navigation system be disabled? And when in full operation, anything that is problematic tends to turn off, with the dire consequences that have sometimes occurred.
Another example is frequency inhibitors mounted on armor to avoid remote controlled mines and explosives. They send out high-frequency signals that affect radio equipment, among other things. When you want to use the radio you tend to turn off the inhibitor, which results in exposure to a bomb. If the inhibitor interferes with the radio, it switches it off and loses contact with the rest of the units.
The interaction that occurs between electrical and electronic devices due to the electromagnetic fields they create and interact with each other is indeed a problem that must be carefully controlled. Electromagnetic compatibility is therefore an area of tremendous concern as it has many implications for communications, navigation and electronic warfare equipment. anything that creates or analyzes waves. We talked about this with engineer Pedro Guevara Maldonado, specialist in electromagnetic compatibility (EMC) for Latin America at Rohde & Schwarz, who will be holding an interesting webinar on this topic on November 26th.
Why do you think interference between electronic modules and communications is a common problem in the aerospace and defense sectors in Latin America?
Electromagnetic interference problems are common in the aerospace and defense sectors. Many defense departments in different countries classify these electromagnetic interference problems as their “Achilles’ heel”. as this jeopardizes the success of their missions or creates serious gaps in national security systems, either because they disrupt their communications (which is already a serious problem); compromise or even destroy their units (aircraft, helicopters, ships, submarines, etc.), even leading to operational fatalities or because their digital systems are bypassed and cause the theft of highly confidential information due to electromagnetic emissions in their computer equipment; and significant economic losses, such as military and civil satellite failures due to electromagnetic compatibility (EMC) issues
But what exactly is electromagnetic compatibility?
Electromagnetic compatibility is the ability of an electrical device or system to work in its electromagnetic environment and avoid interference, ie causing emissions (EMI) or being disturbed, ie being susceptible (immunity = EMS). It is an issue that has since become increasingly important to the aerospace and defense sectors after World War II due to the increased use of electrical and electronic equipment, as well as digital and radio frequency communications (RF) systems.It is extremely important that all of these systems and subsystems function properly with each other without interfering with or hindering each other.
Why is it so important for aerospace and military teams? Can they actually endanger the entire company and seriously impair safety?
Sure, in fact there have been a worrying number of serious situations in various countries due to electromagnetic compatibility issues. For example, certain types of military helicopters of a known model had broadcast immunity problems and the deaths of at least 22 crew members caused various fatal accidents due to such EMC problems. In combat, for example in the Falklands War, a ship was sunk because the missile defense system and communications system were disrupting and they had to turn off the first in order to use the second (a common practice in the various armies when (in the case of air and Space) NASA itself has a public document listing various EMC problems in the space part that have led to errors in their missions.
Which types of devices are most affected by EMC problems? Can these problems be solved inexpensively?
Almost all electrical or electronic devices, but the most important ones are communication devices, computer systems, electronic modules installed in ships or aircraft, or devices on land called EIDs (Electrically Activated Devices).
There are several methods that can be used to alleviate these problems. Some are quite simple, e.g. B. Requesting contracts or quotes for projects or equipment, conditions for compliance with regulations such as MIL-STD-461 in the different versions, inspection programs for the correct landing of the wire harnesses in both power wiring and communication and in the Data, regular measurements on site according to regulations, use of simulation software, but as the same regulations state it is always important to check with measurements that there is no problem. This type is usually used in an EMC laboratory for modules and subsystems or carried out with field measurements for complete systems.
Who should make sure there are no EMC problems and who should fix them if they do occur?
Different departments and parties must be involved, the electronic design must contain practices so that its modules do not interfere with each other, the purchasing department must require in its contracts and tenders that all electronic devices purchased comply with at least MIL-STD -461 and that all Electrical and electronic equipment installation projects conform to MIL-STD-464 and check with your technical department to ensure that this is effectively met or that you do not have the technical skills that have been verified by a third party specialized.
Why are international regulations governing this aspect so important? Can you explain what the RTCA DO-160 civilian and military MIL-STD-461 regulations are?
The international EMC regulations are important as they provide a guide to the minimum requirements that electronic modules, devices, systems and subsystems must meet in this case in order to prevent electromagnetic interference in aircraft, ships, helicopters, submarines, ground vehicles and satellites avoid, etc. In this case the MIL-STD-461 in its latest version which ?? G ?? It contains the minimum tests for electromagnetic compatibility that must be carried out on these devices and modules. The RTCA DO-160 standard is a variant of MIL-STD-461, but focuses on modules and subsystems that are shipped in commercial aircraft.
These are regulations that have been in force for many years, civil since 1975 and military since 1967. Are they adequately adapted to the current situation? Who is responsible for compliance with these regulations?
That’s right, all EMC standards are subject to constant changes made by various committees to keep them up to date with the latest RF technologies. Corrections are sometimes made to include electromagnetic phenomena that were overlooked in their old versions, etc. Unlike commercial regulations, military regulations can be adapted to different environments or electromagnetic environments (EME) to make them even more stringent depending on the application. It is usually the defense departments in the various countries that are responsible for verifying compliance with these standards by their equipment and subsystem suppliers. Suppliers are also responsible for testing their equipment to ensure that it will pass the Department of Defense tests.
What does Rohde & Schwarz offer in this scenario to ensure communication during operations and missions of the armed forces in Latin America?
Rohde & Schwarz has a broad portfolio of products and services. We can assist you in choosing from a wide variety of our products to help you comply with various pieces of military regulations. We also have experts who advise you to carry out the inspection procedures to locate the malfunctions. Or, if necessary, configure a turnkey laboratory with an anechoic chamber and the necessary instruments to meet the application and the required standard. (José María Navarro)
Pedro Guevara Maldonado
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