Important Tips for Selection of RF Power Meters

by Ladybug

Radio frequency (RF) power meters are calibrated broad band measurement devices.  The radio frequency power can be displayed in watts or dBm (decibel-milliwatts). Applications are boundless, RF power meters are an important tool for testing any microwave device. There are many applications involving power measurement including manufacturing test of consumer, industrial and military communications equipment. The applications can have a substantial variation in modulation and power level. When choosing a USB power sensor, you must consider factors such as frequency and dynamic range to fit your requirement. This post discusses the factors you should consider to be able to select the right RF power meters based on your application.

Factors to Consider When Choosing RF Power Meters

Here are a few factors, which may help you make the right decision:

  • Zero and Calibration: Look for sensors that require no calibration or need not be adjusted to zero. You can choose the LadyBug’s RF power sensors featuring NoZero NoCal technology. It is a patented technology, wherein you don’t have to adjust the sensor to zero, or calibrate the sensor before use. The patented process also eliminates loss of communication that is related for zeroing and re-zeroing during measurement in some competitive sensors. With LadyBug sensors, simply measure and get an accurate power level – no need to switch the signal or apply external calibration. These power meter features are particularly useful in test and embedded systems.
  • Accuracy Requirement: Consider the accuracy in terms of calibration, temperature, noise, and potentially other factors. Ideally, first tier NIST traceable standards will be used for the calibration and calibration will be done in accordance with ISO 17025. This will assure the lowest uncertainty.
  • Frequency Range: Power meters are available in a very broad range of frequencies. Power Sensors are broad band devices and include power from all applied frequencies in the sensors range.
  • Dynamic Range: Greater dynamic range can be very useful in many applications. For example, if an attenuator is used to measure high power levels, a high dynamic range power meter will allow greater flexibility in choosing the attenuator. If average power is being measured on a pulse stream, a high dynamic range sensor will allow measurement of low duty cycle. Often, thermal sensors are used in these applications, however thermal sensor do not perform as well as high dynamic range sensors such as a LadyBug LB5900 series power meter.
  • Measurement Speed: Most manufacturers list the measurement speed in literature provided with meters. These include sample rate, measurement rate, reading rate, and so on. The rate at which the analog signal is converted to digital signal is the sample rate. The measurement rate is the speed at which one can get the final measurements. Most of these specifications are not continuous rates. Keep in mind that the detected video filters will dominate the actual settled measurement time in most cases. There is no benefit to sampling 20,000 times per second if the settling time is 250ms.
  • Triggering: A good power sensor has internal and external triggering capabilities which helps optimize the measurement speed. With the help of a trigger output, power measurements can be used in sync with additional power sensors, oscilloscopes, spectrum analyzers, and so on. A trigger output can communicate regarding the sensor measuring the input power to other devices.

If you are looking for RF USB power sensors or USB power meters, ensure you source them from reliable a manufacturer. LadyBug Technologies is a well-known manufacturer and supplier of high accuracy first tier traceable USB power sensors.