Impedance matching using resistors?

[vco96]

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.

 

[g579]

raltron pi matching

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

 

[papyaki]

Hi

Have a look there :

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

* =t

 

[AL0117]

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

 

[activewei]

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 **broken link removed**

Your problem can be solved in seconds

 

[vco96]

8) Thanks alot, problem solved...


Here are the actual formulas used in the attenuation pads:

https://www.rfcafe.com/references/electrical/attenuators.htm

 

[toonafishy]

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

 

[Ashwini Kundur]

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

Hello

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

 

[Element_115]

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.
https://www.maximintegrated.com/app-notes/index.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.
https://www.random-science-tools.com/electronics/PI_attenuator.html

Cheers