Is the power amplifier realizable?

[waterytime]

Frequncey response：385MHz~400MHz;
Pout@P-1dB>=25W CW;
Power supply：12.5V;
I<4.3A @25W ;
IMD3@P-1dB-3dB (That means 12.5W output)<-26dBc;
IMD3@P-1dB-10dB<-40dBc；
gain>=55dB;
gain flatness@25W <1dB；

needs power detector ouput and over vswr indicator

dimision:90mmX50mmX20

 

[vfone]

Theoretically should be realizable this PA. Only the gain requirement is a little higher, which for a 25W RF Power Amplifier design, will be necessarily at least 4 stages of amplification.
More stages will make difficult to meet some parameters including dimension and power dissipation.

 

[waterytime]

Thank you Vfone!

The gain should be reduced somewhat. If the PA is realizable, can you recommend me the transistor for the final stage?

 

[BigBoss]

This config can be proper for your target..

---Stage1-----Stage2----Stage3-----Stage4

---G=20dB---G=15dB---G=10dB---G=10dB--

-11dBm-->+9dBm-->24dBm-->34dBm-->44dBm

Every amplifier can be A Class but don't forget auto-polarization effect at the output stage and previous one because voltage can be very high to drive and shift the OP of the stages.

 

[waterytime]

But if "ever amplifier can be A class", can the efficiency be satisfied?

 

[BigBoss]

But if "ever amplifier can be A class", can the efficiency be satisfied?

Normally 4.3A*12.5=53.75W>2*25W

But the amplifier will enter into AB class with autopolarization and the efficiency may increase by output power.Of course a peak efficiency will be appeared..
Totally depends on the design where your optimization point will be taken into account..