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Thank you for replying
But, I meant how to set this specification based on what? Is it on the transistor used?
I am going to do master project and my topic is designing RF power Amplifier for S-band 2 to 4GHz, so I need to set goals (specifications for the design)
How should be setting?
TQ
Hi,
For maximum power : the criterion is the matching to the load and source charge.
For bandwidth : you must check that the amplifier is stable on whole bandwidth and beyond, that is matched too and that the gain is almost constant.
Bye
For PAE :
In fact, it depend on the class of you amplifier.
Class B , class C or class AB.
For the Noise as we have previously said : the noise is not taken into account for a power amplifier.
In fact for an amplifier, if you choose to minimize the noise, the gain will not be maximum and vice-versa.
Class-A Power Amplifiers have theoretically %50 Drain/Collector Power Efficiency ( not PAE !! ) and it can be between practically %20-%40.
Substrate choice is dependent on your circuit design.Of course cost should be considered.Rogers substrates can be used for S-Band even high quality FR can be used.
Gain : you are considering a power gain which is Pout/Pin and it depends on your class. In class A you can get high power but in AB and C power is lower but efficieny is better. generally it is 30 dBm.
NF: noise figure is not important for PA since we are dealing with large signal
PAE: Power added efficieny which is (pout-pin)/pdiss is max for switched power amplifiers ( E, F, J ...). like 50-60% but for class A is minimum like 25%. The problem is they are not fast and they don't work in high frequencies.
Compression point is also important that you have to consider.
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