Wireless Communications/Satellite Communication


Dear jerry,
         I would like to know,what should be the output of a 3dB combiner being used for combining powers from two High Power Amplifiers transmitting 2 frequency carriers each.Transmit power for HPA-1 is 350 Watts and for HPA-2 is 300 Watts.

Thanks & Regards


Assuming the two HPA are each carrying the same signal at the same frequency and the two signals arrive at the combiner with identical phases you can determine the power by adding the two levels as scalars.  There will be one signal frequency at the output at the sum of the two powers. If there is a phase offset you have to allow for the phase angle between the signals and make a vector addition.  

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Jerry Hinshaw


RF and microwave engineering, hardware and systems applications. Avionics, satellite, and terrestrial communications. Space communications and navigation, geo-location services via satellite and ground-based wireless systems. Systems integration of RF and wireless services. Electric Utility RF Smart Meter (SmartMeter) and Smart Grid wireless devices and networks. Utility Distribution Automation.


30 years experience in microwave and RF systems engineering, radio hardware design and development.

about 20 articles, 2 patents

BSEE MSEE Communications Systems

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