hi, i have a question about AGC loop (using ADL5330 and AD8318)
i'm making the circuit about AGC, you can see the figure1
i want the constant power about -30dBm
so i was changed input power level of VGA(ADL5330) when i fixed setpoint voltage
but power was not fixed
i think in situation of fixing setpoint voltage, even though vga input power level is change, vga out power have to be fixed, is it right?
but it's changable
the VGA(*adl5330) has the gain range of -30 ~ 16 dBm at 2200MHz
and i'm using the 20 dB coupler. so i need detector range of -50~04 dBm, so i select AD8318
but important thing is that the loop is not fixed (for changing the input level & fixing setpoint voltage)
so how can i get this condition
No.1 ) constant power level of -30dBm,
No.2 ) VGA input power level -40~0 dBm (it's changeable)(tell me what range needed)
here's my question
No.1) What's the problem about my circuit?
No.2) what setpoint voltage needed when i get -30dBm of VGA power out level?
No.3) what range of VGA input level needed? how can i decide it?
No.4) R divider value (412/1Kohm) is nesessary?
No.5) i need more specific answer, so tell me more about this solution
please reply quickly
i'm waiting for your answer,