In today’s wireless world, RF signals are transmitted and received to effectively send data and facilitate wireless communications. Among all the parameters to consider in RF design, power measurements remain one of the most critical metrics for designers and operators. With today’s complex modulation schemes, pulsed communication modes, and increased popularity of wireless devices, the need to accurately and efficiently measure RF power has become crucial to obtaining optimum performance from communication systems and components. For example, proof-of-design, satisfying regulatory specifications, adhering to safety limits to protect against the dangers of high-power RF radiation, system efficiency, and component protection, among others, are all situations reliant upon accurate RF power measurements.

Among all the parameters to consider in RF design, power measurements remain one of the most important metrics for designers and operators, especially considering today’s complex modulation schemes, pulsed communication modes, and increased popularity of wireless devices. To accurately characterize modulated or pulsed signals, an important factor to keep in mind is the video bandwidth (VBW) of the RF power measurement test equipment. VBW describes a sensor’s ability to track signal variations of envelope power measurements; envelope power is the amplitude change due to modulation or distortion as a function of time averaged over one or a few cycles of the RF carrier signal – sometimes referred to as peak power. As a result, detecting pulse and peak power measurements correctly relies on the modulating signal’s rate of change in amplitude to be less than the sensor’s VBW.

Power measurements are fundamental when it comes to RF/microwave product design and production, however, communication between the customer and test equipment provider is equally as important. The terms “average power” and “peak power” are often used when expressing desired power measurements, but these terms frequently carry different meanings for different people. Therefore, let’s take some time to clear the confusion and set up terminology that we all can use in common.

In many applications, like wireless communication and radar, pulsed (or bursted) RF signals are utilized. Not only is the level of RF power important, but the shape (RF power envelope) of the waveform can be critical as well.

Oftentimes it is necessary to take measurements of a pulsed signal over an extended period of time. This is important, for instance, in the test and measurement of high-power amplifiers where excessive heat dissipation can eventually distort or degrade the waveform. In addition to power droop, an amplifier may turn off altogether causing a momentary signal dropout, and extended measurement times can pinpoint these missing pulses. Furthermore, engineers often need to verify that the spacing between pulses remains the same over long time periods to ensure no drift has occurred. While extended measurements windows help catch important waveform phenomenon, zooming into specific portions of a signal burst also reveals valuable information. Engineers can utilize time gating techniques to include or exclude desired pulse regions from power measurement results. Boonton’s USB RF power sensors with Real-Time Power Processing (RTPP) technology deliver industry-leading performance, extended measurement duration, and packet time gating for efficient RF and microwave testing.