EMC #63. Radiated Immunity Testing Equipment Guide | Signal Generator, RF Amplifier & Field Probe. скачать в хорошем качестве

EMC #63. Radiated Immunity Testing Equipment Guide | Signal Generator, RF Amplifier & Field Probe.

EMC playlist. Watch these video to understand more on EMC.    • EMC #1. Electromagnetic Compatibility EMC ...   For access to this presentation materials, membership is required: I need the Material PPT Sent me an email to Technologies.Discussion@gmail.com If you need the whole playlist material, send me email and we discuss. Give me some time to response. Thanks. Equipment (Signal Generator & Amplifier) for Radiated Immunity RI, IEC/EN61000-4-3​​. The goal of radiated immunity testing is to verify that an electronic device can function normally, without malfunctioning or failing, when exposed to electromagnetic interference (EMI). Electromagnetic noise can originate from various sources, such as cellphones, microwaves, Wi-Fi routers, or, in some cases from natural sources. For example, if you manufacture phones, it's essential to know whether emissions from nearby devices could affect your product. Immunity ensures that your device can withstand the emissions from surrounding gadgets. Otherwise, interference could cause numerous issues down the line. Anechoic or Semi-Anechoic Chamber As with other EMC testing procedures, radiated immunity testing is conducted in an anechoic or semi-anechoic chamber. An anechoic chamber is a specialized testing environment designed to absorb electromagnetic wave reflections. This provides a controlled environment that minimizes both reflections and external electromagnetic interference (EMI), ensuring accurate test conditions. Signal Generators Signal generators produce the electromagnetic fields used in radiated immunity testing. These devices generate a range of frequencies with power levels to simulate the interference encountered. By producing signals that mimic potential sources of EMI, the signal generator helps test the device’s resilience in scenarios that it might encounter in actual operating environments. During radiated immunity testing, the signal generator is connected to an antenna, which emits electromagnetic waves toward the device under test. Power Amplifier The purpose of power amplifier in RI testing is to amplify the signal from a signal generator to a high enough power level to produce the required electromagnetic field strength in the test environment. Generate field strength: Power amplifier boosts the signal to ensure that the radiating antenna produces the high-intensity electromagnetic fields specified in the test standard (e.g. IEC61000-4-3). Meeting test standards: Different devices must be tested for immunity against varying levels of electromagnetic fields. The power amplifier helps achieve field levels typically ranging from 1V/m to 200V/m, depending on the standard. Compensate for system losses: Amplifier compensates for any losses in the cables, antennas and other system components, ensuring the required field strength is achieved consistently across the test area. Covering frequency ranges: Many radiated immunity tests cover a wide frequency spectrum (e.g., 80MHz to 6GHz). The power amplifier must handle these frequency ranges while maintaining signal integrity. Antennas Several types of antennas are used for radiated immunity testing. The primary purpose of the antenna is to create controlled electromagnetic fields that subject the device under test (DUT) to potential interference, helping evaluate its immunity to external radiation. Common antennas used for testing include log-periodic antennas, which can operate over a wide band of frequencies, and horn antennas, which are effective at higher frequency ranges. Field Probes Radio frequency field probes are used to measure the intensity of RF fields. They provide real time feedback to ensure that the environment within the anechoic testing chamber is within the specified limits for the test.  Closed-Circuit Television (CCTV) During RI testing, the DUT is exposed to high levels of electromagnetic radiation to assess its ability to function correctly in an electromagnetic environment. The CCTV system allows engineers to observe the DUT in real time from a safe, shielded control room, ensuring they do not need to enter the test chamber while radiation is present. Test Procedure Step 1: Setup: The DUT is placed on a non-conductive table in the chamber. The height of the DUT is usually standardized (e.g., 0.8 meters above the ground plane). Step 2: Field Uniformity Check: Before testing, the uniformity of the electromagnetic field is verified across the test area to ensure consistent exposure to the DUT. Step 3: Testing: The antenna is positioned at a specific distance (e.g., 3 meters) from the DUT. The antenna emits electromagnetic radiation across a specified frequency range (usually 80MHz to 6GHz, depending on the standard). The field strength is increased incrementally (e.g., 3V/m, 10V/m) while monitoring the DUT’s operation.