RF Power Sensor Types : Selection Guide, Benefits & Leading Manufacturers

RF power sensors measure signal strength in wireless systems. Selecting the right sensor involves considering frequency range, accuracy and power handling. The popular manufacturers of Power Sensors at RF (Radio Frequency) include Boonton, Keysight, Anritsu, NI, R & S, Mini Circuits etc.

Due to advancement in wireless technologies and use of complex modulation schemes it has become essential to measure the power output of transmitting devices. There are different instruments to measure the power which include power meter, spectrum analyzer and scalar/vector network analyzer. All these instruments use power sensor for measurement of the average/peak power.

RF Power Sensor types

RF Power sensors are categorized into various types based on their measurement principles. They are bolometer or thermistor sensor, thermocouple sensor and diode sensor.

Thermistor Sensor : This sensor type uses wheatstone bridge based design. In this design, thermistor is used as one of its arm element. When RF energy is passed through the thermistor, its temperature varies which results into change in resistance. To maintain balance, feedback loop adjusts the DC power to the bridge. This change in DC power is directly proportional to the applied microwave power. This sensor type offers best linearity but has lowest dynamic range.

Thermocouple Sensor : It uses two basic principles viz. Thomson effect and Peltier effect for power measurement. It offers very accurate power measurement. This thermocouple sensor measures RMS power which is independent of modulation technique. It offers average power measurement for different types of signals. It is the slowest measurement device due to settling time.

Diode Sensor : In this sensor type, power to be measured is applied to load resistor connected in series with diode and parallel to a capacitor. When the applied power is increased, diode controls current/voltage across the capacitor element. This is read and converted into suitable power measurement.

Selection Guide

Following specifications are considered while selecting RF Power Sensor for your requirements.
• Power sensor measurement technology used
• Frequency range
• CW dynamic range
• SWR (Standing Wave Ratio)
• Rise time
• Sensor linearity
• RF connectors used

Advantages of RF Power Sensor

Following are some of the benefits of power sensor used in RF design, development and testing.
1. Offers accurate Power Measurement
2. Broad Frequency Range Support
3. Offers higher sensitivity & dynamic range
4. Offers fast response time
5. Compact & Portable Design and available in USB or handheld formats.

RF Power Sensor Manufacturers

Following table lists popular manufacturers of RF Power sensors of different types.

Manufacturers Description
Boonton Electronics, United States Models : RTP5000 Real time Peak Power Sensors, RTP4000 Real time true average power sensors, 55 Series Wideband USB power sensor, Average and CW power sensors etc.
Website : boonton.com
Email : info@boonton.com
Keysight Technologies Models : 8480 series power sensor, E-Series CW power sensors, E9300 Average power sensors, E9320 peak and average power sensors etc.
Website : www.keysight.com
ANRITSU CORPORATION Models : MA24400A USB peak power sensors, MA24330A microwave CW USB power sensor, MA2400xA Thermal sensors, MA247xD series standard diode sensors (CW), MA2411B Pulse sensor etc.
Website : www.anritsu.com
National Instruments Corp. (NI) Models : USB-5680/5681/5683/5684
Website : www.ni.com
Rohde & Schwarz Power sensors are available in range from 50 MHz to 67 GHz and covers power measurement range from -70 dBm to +23 dBm.
Website : www.rohde-schwarz.com
Mini Circuits Models : RF Power detectors, USB/Ethernet Smart Power Sensors are available in various specifications with frequency range from 9 KHz to 8 GHz and in power levels from -45 to +20 dBm.
Website : www.minicircuits.com
AR Inc. USA Models : USB Pulse Power sensors with various models are available.
Website : www.arworld.us

Conclusion

A precise RF power sensor improves system performance. Choose from leading manufacturers for accurate power measurement solutions.


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