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digital attenuator vs. T resistor network attenuator

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robismyname

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I have an application where I need to attenuate some RF (2.4Ghz) prior to the antenna on the TX side.

im trying to evaluate the pros and cons of a DSA vs a Analog attenuator made of a resistor network.

Are there any issues from the perspective of performance(electrical,physics) that would negatively impact the performance of a attenuator made from a resistor network? Im thinking thermal issues, signal delay, etc???

Are there instances where a DSA isnt the best option again in perspective of electrical and physics parameters?

I dont need to know about cost advantages just performance advantages.
 

If you just want a fixed attenuation, then I can't see any reason why you would use a DSA over a resistor network. A resistor network should have at least as much power handling and precision, and excellent bandwidth. You only use a DSA when it's necessary to vary the attenuation electronically.
 

robismyname said:
I have an application where I need to attenuate some RF (2.4Ghz) prior to the antenna on the TX side.

im trying to evaluate the pros and cons of a DSA vs a Analog attenuator made of a resistor network.

Are there any issues from the perspective of performance(electrical,physics) that would negatively impact the performance of a attenuator made from a resistor network? Im thinking thermal issues, signal delay, etc???

Are there instances where a DSA isnt the best option again in perspective of electrical and physics parameters?

I dont need to know about cost advantages just performance advantages.
Click to expand...

A DSA allows you to Vary the Attenuation, but when you change Values there
can be a short period of time where the attenuation goes to 0 dB. This will
have the greatest effect when going form Half Scale to Half scale + 1 . Also you will
need to route Digital lines near your RF, take care in doing that routing.

A Pi Atten Network will be have a Fixed Value. That's good because it will not
change, and it will give a constant match/load to the Antenna. You will have to
make sure the resistors can handle the RF Power. At 2.4 GHz using 0603 size
Resistors will not cause any type of delay, but try to use a size that matches your
(Zo) Characteristic Impedance of the trace the Pi network is on.

Good Luck
 

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