CPW SM attenuator chip
CPW SM attenuator chip
(OP)
I am using a nice little 3dB surface mount attenuator, roughly 0805 size, which works up to 20GHz. Unfortunately it only has three terminals; in, out, and ground. What I really want is the same thing but with two ground terminals so it fits more symmetrically on coplanar waveguide.
Has anyone seen such a device? Manufacturer’s name?
Has anyone seen such a device? Manufacturer’s name?





RE: CPW SM attenuator chip
htt
RE: CPW SM attenuator chip
It is interesting that all three of the mini-circuits offerings have two ground connections. It is hard to imagine being able to design such a component to have only one ground in fact!
Pity they only work to just above DC
RE: CPW SM attenuator chip
It's perfect for CPW, it's a few mils thick and just lay it across your contacts similar to a chip resistor used in an isolated power divider. Trim the length to get the 3 dB loss. RCard comes in impedance 10-400 ohm's per square. This would be similar to a rotary vain attenuator in waveguide too, just some lossy stuff in your field.
Now the bad part, the perfect 3 dB loss won't be seen over a wide bandwidth. It's like the loss of a cable, more loss at fhigh. So depending on your bandwidth, it may be usable.
kch
RE: CPW SM attenuator chip
RE: CPW SM attenuator chip
Good luck.
kch
RE: CPW SM attenuator chip
RE: CPW SM attenuator chip
Previously, I worked on stripline Microwave Lenses using this material where we etched this Omegafoil over 4-18 ghz bandwidths to make a 2:1 power divider resistive load for isolation purposes. The layers are dielectric/Rcard/copper cladding. Removing the copper cladding leaves Rcard which is in contact with the copper foil.
If you etched your 4 or 5 resistors, that might work.
kch.
RE: CPW SM attenuator chip
I have designed both T and Pi attenuator chips that they have manufactured for me for use to 18 Ghz, but they are larger than 0805 in order to handle higher power levels.
These chips http://www.micrometrics.com/pdfs/AP_Datasheet.pdf
are very small (.03" x .03") and have 4 leads (Pi configuration) and are rated to 40 GHz.
David
RE: CPW SM attenuator chip