Design of RF Power Amplifier
supply voltage = 1v
current < 3mA
gain= 15dB
operating frequency= 2.35G to 2.55G
s22 output matching < -10dB
output power = 0dbm
output p1db = +3dbm
Any design tips or references would be greatly appreciated. Thanks!
1) select a device according to operating frequency, gain, supply voltage, power and etc.
2) plot DC characteristics and determine DC operating by using Prms = Vds x Ids. Prms is RF output power.
3) do impedance matching for the PA using commercially available matching tools (e.g ADS and etc). make sure the matching network within the Qmax circle. Q = circuit Q.
Qmax = Fo/3dB BW
Fo = centre frequency
3dB BW = 3dB bandwidth
Qmax = maximum circuit Q which meets the bandwidth
you may do loadpull to get input impedance and output impedance if you have test setup available before designing PA matching network.
any tips on transistor sizing? also, input matching is not a required spec for my design
what do u mean by transistor sizing? are u designing MMIC PA?
input matching surely required..
i mean transistor sizing as in what I should be gm value and such should I try to achieve. For the VCO i sized the transistor so that the gm value was greater than 1/Rp in order to have oscillation.
I'm not sure why but my advisor said we did not need to do input matching.
then you are talking about MMIC design. im a discrete designer. someone else will answer your next questions.