I am trying to use ADS to create the scheme of an amplifier which includes the following elements


Description = 100 MHz Short Ferrite Bead, Surface Mount

Part Number = 2743019447

Manufacturer = Fair--Rite


Description = 5.6 pF Chip Capacitors

Part Number = ATC600B5R6BT500XT

Manufacturer = ATC

However, I am unable to find ferrite beads in the components library (should I use simple inductors instead?). Also, what is the importance/relevance of the part number and manufacturer? How should this information affect the components I select from the components library? I'd appreciate some insight on this, please.

  • \$\begingroup\$ Huh? What's "Advanced Design System", and what's a "scheme" in relation to a amplifier? \$\endgroup\$ Commented Aug 31, 2017 at 20:29
  • \$\begingroup\$ @OlinLathrop ADS is a pretty well-known RF toolkit... and I feel you should be able to figure out what they meant by scheme. \$\endgroup\$
    – jalalipop
    Commented Aug 31, 2017 at 20:37
  • \$\begingroup\$ @jalali: The point is the OP should say it right and not be sloppy like by using "scheme" where he apparently means "schematic". \$\endgroup\$ Commented Aug 31, 2017 at 21:31
  • \$\begingroup\$ English might not be his first language. He may have just made a mistake. Maybe he's a newbie and thought "scheme" is correct. Why get snarky when it's easier to just edit his question? I would if I had sufficient rep. \$\endgroup\$
    – jalalipop
    Commented Sep 1, 2017 at 12:48
  • \$\begingroup\$ @jalal: Because if I just fix it for him, then he's got no reason to be more careful next time. We don't want people dumping slop on us without consequences. \$\endgroup\$ Commented Sep 1, 2017 at 17:47

1 Answer 1


At RF, it is generally preferable to model parasitic behaviour as accurately as possible. A capacitor may look like a capacitor at low frequency but at a few hundred MHz parasitic inductance may actually dominate the device's impedance.

Putting a simple ideal passive model is fine for initial simulations, but before building the amplifier you probably want more accurate models for your sim. Most reputable manufacturers provide SPICE models for their parts which take parasitics into account, and many vendors of RF-specific passives also provide S-parameters. You can import these into ADS to provide a more accurate simulation.

Finally, in the case of a ferrite bead, an inductor alone isn't a great model. An ideal inductor is lossless - it will not absorb energy. In contrast, a ferrite bead is intentionally lossy in order to convert high frequency energy into heat. Fortunately, you should be able to find equivalent circuit models of ferrite beads from most major vendors like TDK and Murata.

  • \$\begingroup\$ thank you for your prompt and elaborate response to my query. However, having read your answer, I am still not sure how to find and include all these highly particular components in my scheme. Should I look for them online and upload them to my components library? I hope you could pardon the possible banality of my questions :-) \$\endgroup\$
    – peripatein
    Commented Aug 31, 2017 at 20:39

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