470-860 MHz Amplifier

[yashar]

I would like to increase the -18dbm analoge TV signal to 10w peak sink. As the power amplifier the LDU60 module from RES can be used which has 16dB Gain. So what configuration can be used as a drive amplifier for this application with the minimum number of stages and maximum gain slope of +/- 1 dB in whole UHF band?
Thanks a lot for your guidance.

 

[BigBoss]

10W=40dBm
Amplifier Gain should be 40 - (-18 )=58dB !!
This will be multistage amplifier and last stage may have around 8-12dB gain and I guess you have to use 2-3 stages to reach this power level.
The stages will have A-Class amplifiers because your signal is analogue and amplitude modulated so they must be very linear.Gain ripple for these kind of amplifiers should be +/- 1dB in ideal.
An example link budget can be like this..

20dB+16dB+14dB+8dB=58dB
-18dBm+20dB+16dB+14dB+8dB=40dBm

 

[yashar]

Dear BigBoss

Thanks for your answer. But the problem is that cascading amplifiers according to that link budget will lead to an overall gain slope of about 4dB in whole desired UHF band (in the best case). Is there any solution to decrease the gain slope to maximum 2dB in this application?

 

[DDavid]

try to use triuint (wj) ap603 as driver

david

 

[BigBoss]

Dear BigBoss

Thanks for your answer. But the problem is that cascading amplifiers according to that link budget will lead to an overall gain slope of about 4dB in whole desired UHF band (in the best case). Is there any solution to decrease the gain slope to maximum 2dB in this application?

If you use positive slope for each amplifier, the overall slope will be as you wish.For positive slope, there are some techniques such as peaking,feedback with phase shift,intentionally designed matching circuits etc.But you should use a RF simulator to arrange all of them...