impedance matching using resistors

I'm looking to match a 75 ohm source to 50 ohm load. Is it possible to use a resistive pad much like a pi attenuator. Little attenuation is not a problem.

Thanks.

Download the free Milmega RFCalc prog. It is useful for many ather thing too
hxxp://www.milmega.co.uk/downloads.php
In Tools Calculators,Pads menu item you get what you asked for
g579

Hi

Have a look there :

h**p://www.raltron.com/cust/tools/t_attenuator.asp

* =t

Hi,

For measurement purposes (to match your 50 ohm test instrument to 75 ohm) you should use some readily made adapters like BMP-5075 from Minicircuits. It has good quality 50 respectively 75 ohm connectors, excellent linearity, and return loss over the 5-2000 MHz. You can try a home made one, but you will never obtain so good results.
The simplest resistive impedance matching pad consist of 2 resistors: from the 75 ohm side series 43 ohm to the 50 ohm side, and at the 50 ohm side a 86 ohm resistor to ground. The insertion loss is about 5.7 dB

Good luck,

Al

VCO96: I think to match 50 to 70 ohm, it can be easily done by using resistive pi or tee network, you can download software uploaded at http://www.elektroda.pl/eboard/ftopic71283.html

Your problem can be solved in seconds :)

8) Thanks alot, problem solved...


Here are the actual formulas used in the attenuation pads:

http://www.rfcafe.com/references/ele...ttenuators.htm

What you are looking for is a minimum loss pad. Here is a good paper on the subject


h**p://www.maxim-ic.com/appnotes.cfm/appnote_number/972/ln/en

Hello

Can you please provide the formulae used to calculate the resistance values in the above solution.

These are called "Min-Loss Pads". There is a minimum amount of loss that you must incur when going from one
Zo value to another.

Here is a good tutorial.
http://www.maximintegrated.com/app-n...dex.mvp/id/972

You can also search for the Pi / T Pad attenuator tools on line and see what happens when you try
to make a 3dB pi-pad that has Z1 = 50, and Z2 = 75.
http://www.random-science-tools.com/...ttenuator.html

Cheers