SMD packages for broadband attenuator with resistive/capacitive voltage dividers

[manuel1139]

I'm going to build an broadband attenuator with resistive/capacitive voltage dividers. For 1:10 / 1:100 division with 1megaOhm Impedance I planned to use 10k 90k and 900k 0805 smd package resistors. However I did not find anything near that.

I found some wire bond measurement resistors with this values - however I have not found anything about their behavior in high frequency applications.

Are there any measurement resistors in smd packages out there? Or what is the way to go?

Best Regards,
Manuel

 

[barry14]

Re: Broadband Attenuator

You don't say what frequency range you are interested in. Broadband to one person is not broadband to another. However, if we assume that you are interested in frequencies up to at least 1 MHz, then the values of resistors you are looking at is too high. Stray capacitance will severely limit t your attenuator performance. For example, 1 pf of capacitance across a 900k resistor results in a 3 dB bandwidth of less than 200 kHz and thus would be useless as a broadband attenuator out to 1 MHz. You need to use much lower value resistors; probably no higher than 10k, even lower if your frequency range extends beyond 10 MHz. It should be easier to get these values in small packages than the values you have been considering.