MLP - RF Cafe Forums

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gogober
Post subject: MLP
Unread postPosted: Thu Nov 25, 2004 1:35 pm

can some one explain me this circute,and why Rs>RL?
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Itay
Post subject:
Unread postPosted: Thu Nov 25, 2004 3:03 pm

Greetings Gogober:

this circuit is called L-Pad attenuator, and is used to match between 2 impedance levels. The ratio doesn't have to be necessarily RL>RS, it can be also RS>RL, all depends on the application. This attenuator is basically derived from the T attenuator (with one of the series resistors is reduced to value of 0-ohm). This attenuator is designed to have minimum attenuation value.

You can calculate the resistor values of R1, R2 according to the following formulas:

R1=SQRT( RS(RS-RL))

T2=SQRT ((RS*RL^2)/(RS-RL))

Good luck,
Itay

Posted 11/12/2012