Satellite Communications/Reflected Power in TWTA

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Question
QUESTION: Hi Rao

What is Reflected power in a TWTA? What is it's importance & is there any ideal range?
Many thanks.

ANSWER: Hi Mr Mohsin,
Instead detailing on your Question , I refer you to the following
website Courtesy: COMPLEXTORIAL.COM) which clearly explains all about
understanding
TWT characteristics. Hope this will satisfy your TWT awareness.

http://complextoreal.com/wp-content/uploads/2013/01/twta.pdf

Cheers/GTRao

---------- FOLLOW-UP ----------

QUESTION: Dear Rao!
Thanks for the link you provided. Indeed it was useful, but unfortunately it does not talk about reflected power. Also, I think the document is a bit old as the power mentioned for TWTAs are much lower than the ones being used now.

Answer
Hi Mr Mohsin,
I am sure you have gone through the mentioned article. There is nothing like OLD
and NOW or NEW in terms of Technology. TWTA is as old as Electronics and Tubes!!
If you understand the basics, it will be clear as to how the required standards
are interpreted to be applied to contemporary applications, that's all. And
Reflected power is not a specific parameter for TWTA only and it is the generic
parameter in Microwave applications. As you may be aware of Maximum power transfer
Theorem in antenna Engineering, it is essential to match the Power Amplifier to
the Load for Maximum Power Transfer: otherwise the efficiency of TWTA degrades.
That is all and even for solid state PAs it is a parameter for consideration.
The values used now a days, as you say, are for the specific applications and
Radar systems for better coverage. If only you can interpret the basic parameter
significance it is easy to apply for NOW or for ever. I am not sure what is
the one used now you may mean? Power mentioned for the TWTAs depend on the actual
frequency and operation in CW mode or Pulse mode etc. May be if you can enlighten
me with the context where you are using this, it helps me to be specific.
Cheers/GTRao

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TIRUMALA RAO G

Expertise

Satellite Communications Applications, Link Calculations, Teleports, Earth Stations,VSAT, Tracking, Mobile Communications, Next Generation Networks.

Experience

40 Years. Indian Space Research Organisation, PANAMSAT, Satellite Based VSAT Networks, IP Networks.

Organizations
ISRO, PANAMSAT, Engineering Institution for Higher Education (GVP College of Engineering), Consultancy.

Education/Credentials
Graduate in Electronics and Communication Engineering with Distinction. Guiding scholars for their Doctoral thesis in related areas in Academics.

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