Inter-Stage match of Linear PA!

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fxxjssc

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pa interstage match

Dear all
My PA is two stage Class AB power amplifier, which
target ClassAB output 15dBm with 1.8V power supply @900MHz。
The structure is as following:
power stage:
structure:cascode ClassAB
input power:5dBm
power gain:10dB
output power:15dBm
input voltage swing needed:1V
bias voltage:1V
bias resistor:10Kohm
input impedance:6.5Kohm res parall with 166fF cap

drive stage:
structure:cascode ClassA
input power:-10dBm
input voltage swing:0.2V
power gain:16dB
output power:6dBm
bias voltage:1V
bias res:10Kohm
output impedance:4Kohm res parall with 373fF cap
what unsure are :
1. is the power and gain reasonable?
2. About interstage matching, is it possible to change bias res of
power stage to control its input impedance ?
3. To match output impedance of drive stage, is it good way to tune out
the two parall cap 373fF + 166fF? for 900MHz, more than 10nH L is
is needed to tune them out and is impossible for 0.18um process.


Best wishes
 

i also wanner know how to design the interstage matching, if we only use a big cap to couple, then we can only simulate the power gain together, am i right? second, will the PA oscillate if there is no interstage matching? i am working on a 2.4GHz cmos power amplifer these days, it oscillates at the output node of the 1st stage, the architecture is the same as fxxjssc's. i need help, give me a hand please, thanks alot^^
 

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