Reverse/Reflected Power protection

[naveedali99]

hi to all...

i am generating a modulated signal and want to transmit the signal through Power amplifier. i want help regarding the reverse power protection and other parameters which can damage my generating side or power amplifiers....


I need all the protection possibilities for my generators, power amplifiers and antenna because all the much costly

 

[chuckey]

How about the frequency and the relevant power levels?. And what drive muting control you have?
Frank

 

[BigBoss]

I think the first protection circuit is not ncessary because power level which is delivered to PA will be relatively low and the input impedance of the PA is more or less matched.The generator output is-probably- self protected against such low power reflections and tolerated. For output, you may use "Ferrite Circulator" depending on the frequency and power level.But note that, it's not possible to find a circulator for every frequency and power levels.

 

[D.A.(Tony)Stewart]

It would be constructive to define the environmental specs, power specs, limits and sources of risk in tbis vague question, unless this is just a philosophical question.Some sources not considered may be EMP, ESD and Solar flares.

 

[naveedali99]

Thanks for replying me

@chuckey
i have more than one frequency range
500MHz band, 1500MHz band and 3000MHz band. each have its own generating side, Power Amplifier and Antenna

@BigBoss
Turning on the power amplifier without Antenna reverse all the power to its input. i am using nearly 30W to 100W. if this all power reflect on the input of the PA, its guarantee that generating side will burn easily

@SunnySkyguy


500MHz 200W
1500MHz 50W
3000MHz 30W

 

[BigBoss]

Thanks for replying me
@BigBoss
Turning on the power amplifier without Antenna reverse all the power to its input. i am using nearly 30W to 100W. if this all power reflect on the input of the PA, its guarantee that generating side will burn easily

If full reflection occurs, the amplifier will be burned first so don't worry about input side.
Since you use a circulator at the output, no full reflection will be occured toward to the amplifier.In additional to this, there is amplifier reverse isolation about 20-25dB.
The essential is to use a convenient circulator at the output who will absorbe reflected waves on it self.

 

[naveedali99]

thanks for your reply.
after the amplifier, i will use circulator. can u suggest me anyone. i have not much time to develop a circulator. can you tell me any place from where i can buy it.

secondly lets make it exception that if PA reflect the whole power in its input, then the generator will definitely burn. for the sake of protection, advise something.

If full reflection occurs, the amplifier will be burned first so don't worry about input side.
Since you use a circulator at the output, no full reflection will be occured toward to the amplifier.In additional to this, there is amplifier reverse isolation about 20-25dB.
The essential is to use a convenient circulator at the output who will absorbe reflected waves on it self.

 

[BigBoss]

thanks for your reply.
after the amplifier, i will use circulator. can u suggest me anyone. i have not much time to develop a circulator. can you tell me any place from where i can buy it.

secondly lets make it exception that if PA reflect the whole power in its input, then the generator will definitely burn. for the sake of protection, advise something.

I said it before, if there is a circulator at the output no full reflection will be occured.
Circulators are very special components and they are unidirectional ( ideally).There isn't any other passive unidirectional components than the circulators.
You can find many manufacturers and distributors but it's worth to look at this..
**broken link removed**

 

[chuckey]

The most important thing to do is to paint all the relevant coax connectors red. This way you will not disconnect them without disconnecting the input first.
Frank

 

[naveedali99]

i need a upconverter for higher frequencies. i searched for the frequency mixers and i find minicircuits mixers.
" **broken link removed** "

can you guys specify that it will work fine for higher frequencies and any kind of issues which can be faced

 

[naveedali99]

protection on the input side of the amplifier...... urgent reply.

i want to save my generating side. kindly suggest something from minicircuits

 

[davenn]

protection on the input side of the amplifier...... urgent reply.

i want to save my generating side. kindly suggest something from minicircuits

do you not understand what people have been telling you ?

what do you think you are protecting the generator from ? .... its own output power ?
what is the output power of the generator into the amplifier ?

cheers
Dave