HIRF, or High-Intensity Radiated Field, is radio frequency (RF) energy that is so strong it has a significant impact on the performance of an EUT. As a result, radiated susceptibly requirements are mandated by the FAA (Federal Aviation Administration), EASA (European Aviation Safety Agency), and other aerospace regulatory agencies. Common sources of these high-intensity radiated fields come from external radiators such as radars and broadcasting, and from transmitters installed on the aircraft.
The greatest concern of high-intensity radiated fields is on aircrafts’ electrical and electronic systems which can be damaged or destroyed, causing the aircraft to malfunction during flight. To prevent such disasters from occurring, HIRF regulations exist to ensure that aircraft electrical and electronic systems will continue to operate safely without interruption, failure, or malfunction.
The Code of Federal Regulations (CFR) for the United States government, along with other standards, call out for HIRF testing and protection against HIRF. These standards exist to ensure that every electrical and electronic system installed in an airplane must perform regardless of any interference to guarantee a safe flight.
14 CFR 23.1308
14 CFR 25.1317
14 CFR 27.1317
14 CFR 29.1317
RTCA/DO-160 Section 20
The effects of HIRF encounters should be assessed to determine the degree to which the aircraft and its system’s safety may be affected. HIRF testing replicates the pulse modulations and energy levels that high power radars generate to ensure aircraft equipment electromagnetic immunity (EMI). Conducting HIRF testing requires specialized EMI test equipment used to emulate RF and evaluate the resistance of the electrical and electronic systems to the high-intensity radiated fields. Equipment used to perform HIRF tests include signal generators, pulse amplifiers, RF power meters, EMC antennas, and field strength monitors and probes.
A signal generator is an electronic device that generates repetitive or non-repetitive electronic signals in either digital or analog formats. It begins the process of simulating high intensity radiated fields.
Signal generators are generally used in testing, troubleshooting, designing, and repairing electronic instruments. There are many different types of signal generators that have different purposes and applications. They include function generators, RF and microwave signal generators, pulse generators, and sweep generators. Find out more about signal generators here.
A pulse amplifier is an amplifier designed specifically to amplify electric pulses without changing their waveforms. Pulse amplifiers amplify RF signals and increase the amplitude of an input signal to a desired output level. HIRF testing requires the use of high power RF amplifiers in order to emulate the radiated field of lightning to conduct tests.
Amplifiers are additionally used in research and development, testing, troubleshooting, and finalizing compliance testing. They are used to simulate interference signals with devices to ensure that they will operate correctly in real world conditions. The main characteristics of an amplifier are frequency range, power, impedance, linearity, class, and the technology they were constructed with. Find out more about pulse amplifiers here.
A Continuous Wave Amplifier typically amplifies a sine wave or an AM or PM modulated sine wave for a host of different applications from EMC, RF, Millimeter-Wave, Electronic Warfare or other applications. Advanced Test Equipment Rentals stocks CW Amplifiers from DC-40 GHz and offers many solid state models & TWT’s. Find out more about CW amplifiers here.
RF Power Meters & Sensors
RF power meters and sensors measure the output power from the amplifier during HIRF testing and other radiated immunity testing. When an output signal level is too low, the signal can be obscured in noise. But if the signal level is too high, distortion will result and the performance will be nonlinear. Damage is the worst possible outcome in RF immunity testing.
When choosing a power meter, the output power level of a component or a system is typically the most important factor in the design and specified performance of RF and microwave equipment. Power meters measure continuous wave (CW) or pulsed waveforms in terms of peak power or average power, which is useful for testing, manufacturing, R & D, maintenance, and more. As a result, measuring the RF power level to determine the performance of the device under test is often necessary. The frequency range and the power range are also important specifications to consider. Read more about RF power meters & sensors here.
EMC antennas in HIRF testing are used to create the electromagnetic field. These transmitting antennas produce radio waves and microwaves that are emitted from the antenna with high intensity and strength, creating HIRF.
Advanced Test Equipment Rentals carries a variety of antennas HIRF and other types of test. ATEC inventory consists of horn, biconical, dipole, log periodic, loop and many other antennas. Read more about EMC antennas.
Field Strength Monitors and Probes
Field strength monitors and probes are designed for measuring and monitoring radio frequency (RF) electromagnetic field strength. They are essential in monitoring the strength of HIRF in testing.
These field strength monitors are ideal for RF power measurement for transmitters, measuring high frequency (RF) electromagnetic wave field strength, establishing personal and environment safety around electromagnetic fields (EMF), monitoring a broadband RF range or frequency-specific areas, and more. The probes offer precise measurements of complex scenarios and radio frequency signals. They also provide efficient on-site measurements. Read more on field strength monitors and probes here.
Amplifier Research FL7040 Field Strength Probe
Amplifier Research FM7004A Field Monitor
Amplifier Research FP7018 E Field Probe
ETS-Lindgren HI-6053 Electric Field Probe
All these and other equipment for HIRF Testing are available for rent from Advanced Test Equipment Rentals (ATEC).