Introduction to RF Power Measurements
Power is a necessary parameter to measure across a wide range of modern applications. Power is defined as work per unit of time. It includes units of measure such as horsepower, watts, calories per second and BTU per second, depending on the domain of interest. Electrical power is typically measured in watts, defined as one Joule per second. With RF circuits, dBm, a logarithmic representation of power level relative to the milliwatt, is often used.
An assortment of instruments and methods are used for measuring power. In this article, we will limit the discussion to electrical power, defined as voltage multiplied by current. We will further narrow the discussion to RF power, which implies higher frequency, say signals greater than 10 MHz, requiring more sophisticated instrumentation than a voltmeter due to the behavior of high-frequency electrical signals.
It is important to select the appropriate technique for measuring RF power in a given scenario. If the signal level is too high, the instrument input will become saturated; distortion, harmonics, spurious and other non-linear signals could occur. If the signal level is too low, the signal will be buried in the noise floor, making it difficult to retrieve.
A Short Primer on RF / Microwave Power Sensors
Proper power measurement techniques are important for achieving accurate results. Mini-Circuits’ PWR-series of smart power sensors now furnishes the measurement professional with the ability to make accurate peak and average measurements of CW, modulated, and pulsed RF signals at a more cost-effective price point than generally available anywhere else in the industry. Whether it’s a high dynamic range solution or a high frequency solution to 40 GHz, Mini-Circuits offers a power sensor to suit most RF/microwave engineering needs and budgets.
Mini-Circuits’ lineup of entry-level power sensor products capable of CW and true RMS measurements presents an economical option for applications requiring the measurement of CW signals to 8 GHz and modulated or multitone signals to 6 GHz. Both CW and true RMS power sensors and can be found on our main smart power sensors page.
