AMPLIFIER_200_400MHz - RF Cafe Forums
Post subject: AMPLIFIER_200_400MHz Posted: Thu Nov 03, 2005
Joined: Thu Nov 03, 2005 5:34 pm
I want to make about following parameters
I need relating information:
- the influence of temperature
on parameters the VDMOS, LDMOS.
- the selection of transistors (what
- on what was one should be careful,
I found the
solution firms polyfet, motorola, philips, macom.
Are yet some firm
thanks for information
subject: Posted: Sat Nov 05, 2005 11:23 am
Joined: Mon Jun 27, 2005 2:02 pm
The vendors you mentioned are the right
ones. You should carefully check for the right device. Most of the vendors
provide an application circuit for each device. The most important part
of a PA circuit are the matching networks in the input and output. These
networks also are designed for the required BW of operation. Your BW
is octave, which is very wideband. So you should carefully examine this
You should also pay attention to the bias feesing circuit.
There should be a good isolation between the the RF output and the DC
supply, and the bias level should be adjusted to provide the required
linearity and output power level.