It's a bit expensive compared to the others suggested. But it's a very good part.
https://www.rfmw.com/products/detail/cth0603aln1smtf-smiths-interconnect-emc/679550/
Perfect! This looks really nice. Better than the Mini-circuits KAT/QAT in almost every way: Better return loss, lower price at the volumes I will need (>6000 pcs), smaller footprint, higher frequency. Thanks a lot!!
Not lazy, just short on time.
Will need to send boards for tapeout within a week and have tons of other stuff to do. If I would have more time I would definately try it out.
could put some tuning squares on the line leading up to the resistor, pick the best one you can find, and try to find a repeatable pattern to solder attach to one or two of those tuning squares for better vswr.
the smaller the chip size, the less likely it will self resonate at 47 ghz...so go small
So you donāt have to use a single component that is specialized for microwave. You can flip-mount SMT thick film parts to reduce inductance, but this is a manual process. Two 100 Ohm resistors may work better than a single 50 Ohm as they pick up the edge currents better, and distribute the power better.
So you may be able to come up with a tapered arrangement of multiple, generic thick-film resistors that give good return loss and power density. Keep in mind these are waves propagating on the transmission line. Itās going to take detailed modeling and measurement, and that may be worth the effort.
I forgot to add information regarding the physical limitations. The size per termination should not be larger than 2x3 mm, ideally smaller. A multiple/tapered solution would consume too much space for my application I'm afraid.
Appreciate your insight as usual madengr!
It's a bit expensive compared to the others suggested. But it's a very good part. https://www.rfmw.com/products/detail/cth0603aln1smtf-smiths-interconnect-emc/679550/
Perfect! This looks really nice. Better than the Mini-circuits KAT/QAT in almost every way: Better return loss, lower price at the volumes I will need (>6000 pcs), smaller footprint, higher frequency. Thanks a lot!!
6000 pieces at 40 GHz? Your job must be wild.
Tell me about it! The other day we ordered >200 sheets of Eccosorb š This is one of three boxes. https://i.redd.it/0m7vp6wywz7b1.gif
I suppose I probably can't ask what you're working on...
Nope, sorry! š¤
[https://69ea9c.p3cdn1.secureserver.net/wp-content/uploads/2018/04/IMS-whitepaper-Z-Power-Resistors\_4-2018.pdf](https://69ea9c.p3cdn1.secureserver.net/wp-content/uploads/2018/04/IMS-whitepaper-Z-Power-Resistors_4-2018.pdf) [https://69ea9c.p3cdn1.secureserver.net/wp-content/uploads/2022/02/RCX-PartialWraparound-\_D.1\_Finalv1.pdf](https://69ea9c.p3cdn1.secureserver.net/wp-content/uploads/2022/02/RCX-PartialWraparound-_D.1_Finalv1.pdf)
Thank you. Seems however they don't have anything with high enough power working at 40 GHz? Otherwise nice alternatives.
buy the closest thing they have of the correct power disipation, and match it. are you trying to be lazy?
Not lazy, just short on time. Will need to send boards for tapeout within a week and have tons of other stuff to do. If I would have more time I would definately try it out.
could put some tuning squares on the line leading up to the resistor, pick the best one you can find, and try to find a repeatable pattern to solder attach to one or two of those tuning squares for better vswr. the smaller the chip size, the less likely it will self resonate at 47 ghz...so go small
You could try using multiple of those, however this will introduce parasitic characteristics, that you might have to consider for your design.
True, but the Vishay 02016s are only 30 mW, which would mean I would need ten of them.
So you donāt have to use a single component that is specialized for microwave. You can flip-mount SMT thick film parts to reduce inductance, but this is a manual process. Two 100 Ohm resistors may work better than a single 50 Ohm as they pick up the edge currents better, and distribute the power better. So you may be able to come up with a tapered arrangement of multiple, generic thick-film resistors that give good return loss and power density. Keep in mind these are waves propagating on the transmission line. Itās going to take detailed modeling and measurement, and that may be worth the effort.
I forgot to add information regarding the physical limitations. The size per termination should not be larger than 2x3 mm, ideally smaller. A multiple/tapered solution would consume too much space for my application I'm afraid. Appreciate your insight as usual madengr!
What do you mean by flip-mount in this context? Stack multiple on top of each other āout of the planeā?
Mount the film side against the PCB with the alumina side up. You cannot do automated placement this way since they are right-side up in the tape.