RF/Microwave Test Equipment Useful for EMC Precompliance Testing

Virtually every country around the world has some type of electromagnetic compliance (EMC) policy in place to prevent hazardous emissions, susceptible electronics in the marketplace, and to avoid an overabundance of interference. Given the complex nature of EMC, most compliance codes are very strict and the cost of failure is that a product cannot be legally sold in that marketplace. To avoid costly and time consuming delays in product launches, many companies use extensive precompliance testing in house prior to submitting a product design for the battery of third-party EMC testing. Some companies use in-house testing that is essential EMC testing, but this generally involves expensive and specialized equipment run by trained technicians.

Another approach to EMC precompliance is to use RF test equipment and accessories to detect, identify, and troubleshoot a design for unwanted emissions. RF test equipment can also be used to cause intentional interference and perform susceptibility testing of a design. RF test accessories, such as coaxial cables, adapters, and probes can also be useful, and are often essential, as interconnect between the device under test (DUT) and RF test equipment.

The two main forms of EMC precompliance testing are emissions and susceptibility. Emissions describes the electromagnetic (EM) signals that are emitted from a device, while susceptibility describes the impact that external EM signals have on a device. With emissions testing, the DUT is powered and put in several operating modes while being monitored by external calibrated antennas or probes. Susceptibility testing is done with a DUT powered, or not, and subjected to external EM signals using a calibrated antenna.

RF test equipment used in EMC precompliance testing include signal generators, spectrum/signal analyzers, noise generators, amplifiers, low-noise amplifiers, and power meters. Signal generators can be used to generate EM signals at set power levels and frequencies in order to subject a DUT to susceptibility testing, or to test certain parts of a DUT’s circuitry for emissions given a set power and frequency output. Some RF signal generators are also able to modulate their signal output, which can also be useful for EMC precompliance if the modulation mimics the intended output characteristics of the DUT. In this way RF signal generators can be used in electronics design to help ensure certain design decisions meet with compliance standards prior to a complete design or to determine design constraints. High performance coaxial cables, probes, or pigtails may be needed to connect the signal generator to the DUT to provide low-loss and shielded interconnect.

Spectrum/Signal analyzers (SAs) are able to receive signals and provide a measure of the signal energy. SAs can be used with calibrated antennas, probe antennas, or coaxial probes to measure the EM signals emitted from a DUT. In this way, SAs can be used to emulate EMC emissions testing, and may also be used to troubleshoot emissions issues by helping to identify the area of a circuit that is generating the unwanted emissions. As SAs provide both frequency and power sweeps, the type of emission can be further analyzed and may lead to precise pinpointing of the circuit device/component/feature that is generating the unwanted emissions.

Many EMC codes include frequencies in the low gigahertz, but 5G millimeter-wave frequencies, spectrum refarming, and The Internet of Things (IoT) is changing the EMC landscape to include much greater swaths of spectrum and associated compliance testing. Given that 5G compliance and test methods include/will include millimeter-wave spectrum, RF equipment that operates in the millimeter-wave frequencies will become increasingly useful for EMC precompliance.

Useful RF Test Accessories and Equipment For EMC Precompliance Testing

•Pasternack Phase Stable (VNA) Coaxial Cables
•Pasternack Cable Generic Test Cable Assemblies
•Pasternack Skew Matched Pair Coaxial Cable
•Pasternack Precision Coaxial Adapters
•Pasternack In-series and Between-series Adapters
•Pasternack RF Coaxial Probe
•Pasternack Straight Cut Lead Sexless To SMA Female Cable Assemblies
•Pasternack Antennas