What is an EMC power meter?

A power meter is a test instrument used to measure the signal power at the RF frequencies. An RF power meter uses power sensors (usually diode-based sensors) to measure the power level of an RF signal. The measured reading is displayed on the screen of the power meter in dBm or Watts. The power meters can be used to measure CW power, average power, peak power, peak-to-average ratio power, and pulse power of the RF wave. The sensitivity and power range of the power meter are determined by the power sensor used for measurement.

EMC power meters are ideal for use in the EMC immunity test to know the power values of applied RF power for ascertaining whether the EUT is being subjected to the necessary amount of interference to operate correctly in any environment. 

The EMC power meters are also used in RF product design, semiconductor, military, aerospace, and medical industries, and applications involving radar, avionics, electronic warfare, and satellite networks. It is necessary to check the measurement types (i.e., peak power, CW, etc.) provided by the power meter, before selection.

How does a power meter measure RF power?

Modern power meters use high-frequency diodes to detect the RF voltage developed across the terminating load resistor. The diode sensors directly perform AC to DC conversion. Now, the DC output across the terminating load resistor is fed to the power meter, which measures and displays the reading in dBm or Watts.   

RF detection circuit

 Key Specifications of EMC Power Meters:

Channels: Represents the number of channels that can be measured by the power meter. The power meters are available in single-channel and multi-channel options.

Frequency range: Represents the RF frequency range that is supported by the power meter. Usually, it can support the RF frequency range of kHz to GHz.

Measurement range: This represents the RF power measurement range that can be measured by the meter. It is represented in -X1 to + X2 dBm.

Resolution: It represents the smallest change that can be measured by the power meter. It is expressed in dB. For example, power meters may have a resolution of 0.1 dB.

Accuracy: It represents how close the measured value is to the actual true value. It is expressed in ± dB. For example, power meters may have an accuracy ± 0.05 dB.

Output frequency: This represents the output frequency of the power meter for calibration. Usually, it is in the MHz range.  

Interface: Represents the type of interface (for example, GPIB, USB, RS-232) that supports the power meter.

Connectors: Represents connector type that connects the power sensor’s output to the power meter’s input for measurements.

EMC Directory has listed Power Meters from the leading manufacturers. Use the parametric search tools to narrow down on products based on your requirements. Once you find parts that meet your requirements, view product details, download the datasheet, compare products and request quotations. Inquiries sent via EMC Directory are directed to the manufacturers who get back to you with a quote or information.