Selecting elements for the 5014 Directional RF Power Sensor


A variety of element options are available for the 5014 sensor covering a wide range of frequency and power levels. Choosing what is right will depend on what you want to achieve in your application. One generalization we might use is that the 5014 uses DPM/APM elements for average power while the standard 43 elements are typically used for peak power. The latter, too, will measure average power but could yield slightly higher readings. 

The difference between APM/DPM and standard elements is the detector circuitry.  APM/DPM use a square law detector and the standard elements use a point contact diode detector.

The following information will help you gain a better understanding of what you can expect from the element types.


43 Type Elements

The 43 type elements are normally used to measure peak power. These elements can measure the peak power of a system with an accuracy of +/‐8% of full scale as long as the signal meets the following requirements:

  • At least 15 pulses per second (PPS)
  • Minimum pulse width of 15 μs (800 ns if frequency is greater than 100 MHz)
  • Minimum Duty Cycle of 0.01%

In addition, 43 type elements can be used to measure average power in signals with a peak‐to‐average ratio close to 1, like a CW or FM signals. In these cases, the average power is measured with an accuracy of +/‐ 5% of full scale.

Find 43 type elements using the following links:

APM/DPM Elements

The APM/DPM elements are used to measure true average power. True average power means the sensor provides equivalent heating power of the signal, regardless of modulation or number of carriers. These elements can measure average power with an accuracy of +/‐5% of reading from full scale down to 2.5% of full scale.

The APM elements were introduced first for use in our APM-16 analog meter. Then the DPM elements were made for the 5014 and 5010 directional power sensors. The DPM elements have a slightly tighter accuracy spec.

While the 5014 can use use either DPM or APM elements, the two categories should not be mixed, meaning do not use an APM for forward power and a DPM for reflected power or vice versa.

Note: The equivalent heating power is dependent on the duty cycle of a signal. If a system puts out 50 watts with a 50% duty cycle, the APM/DPM elements will measure 25 watts.

Find APM & DPM elements using the following links:

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