All silicon capacitors are relatively expensive, they're specialty parts that generally go into expensive things (mmWave airport scanners, optical backhaul, etc).
TheJoeMan 4 hours ago [-]
Did they build 5,000 airport scanners at once? MOQ is brutal!
IndrekR 3 hours ago [-]
One scanner has way more than one channel…
threatripper 4 hours ago [-]
Figure 1 made me laugh out loud.
stn8188 3 hours ago [-]
It may seem overly simplistic, but 2-port models for capacitors can be configured in series (as shown here) or in shunt (much more common for power distribution network applications). So, as basic as you might think this diagram is, it is entirely expected to be there so that we instantly know if the S-parameters are in series or shunt configuration - it would be more unusual if it were missing.
Neywiny 1 hours ago [-]
I think you're thinking of the other figure. Figure 1 has no connections at all
aaronmdjones 4 hours ago [-]
Same here. That's made my week.
tedd4u 4 hours ago [-]
1 •--||--• 2
Figure 1 block diagram
dlcarrier 4 hours ago [-]
Someone's actually using nF, instead of 0.022uF or 22,000pF.
PowerElectronix 4 hours ago [-]
I never understood why nF is less frequently used than uF or pF. To me, the logical thing is to express the capacity in units that are between 1 and 1000, like it's done with resistors and inductors.
summa_tech 2 hours ago [-]
I, too, had wondered; this seems particularly common in the US. My best theory is that in rough handwriting, n and u/μ can look pretty similar, and everyone sort of agreed to only use u to reduce ambiguity.
nomel 1 hours ago [-]
I heard this, and have witnessed it. One of my first jobs included board rework. There were several times when I had to go ask if they wrote a uF or an nF. The response was always "obviously a uF", because nobody uses nF!
lisper 5 hours ago [-]
Why is this a component? Couldn't you just make one of these out of PCB traces?
bri3d 4 hours ago [-]
Certainly not at these frequencies and corresponding high capacitance values; getting 22nF out of a PCB even with ECM would require quite a large surface area and at 220GHz you can't have that since your wavelength is so short; you'd just be making a giant resonator instead.
IndrekR 3 hours ago [-]
Length of this capacitor is close to half-wavelength of 220 GHz (in vacuum).
Using siblings of this broadband capacitor (40 GHz, same package) in some designs. In assembly, those require decent process control. This 0201M package is closer to 01005 passives in pad size. Typically no solder paste is used, just flux. Solder mask alignment has to be very tight (thin web used as a dam only).
Cost per cap is reasonable where it is actually needed, other parts of the system are often orders of magnitude more expensive at those frequencies where performance matters. Where it gets the very high performance, is pillars/channels etched into silicon quite similar to how DRAM capacitors are made, just a “little bit bigger”. This allows for very low inductance and thus very high resonant frequency.
Eduard 3 hours ago [-]
ECM = Embedded Capacitance Material.
It is a special PCB laminate designed to create capacitance inside the PCB stack-up, typically between closely spaced power and ground planes.
matherial 4 hours ago [-]
No, not if you want 22 nF. That's a pretty substantial capacitance. It would need to be quite big on a PCB. That would mean significant inductance, and thus, bad performance at high frequencies.
A mere 2.40 euros each!
Figure 1 block diagram
Using siblings of this broadband capacitor (40 GHz, same package) in some designs. In assembly, those require decent process control. This 0201M package is closer to 01005 passives in pad size. Typically no solder paste is used, just flux. Solder mask alignment has to be very tight (thin web used as a dam only).
Cost per cap is reasonable where it is actually needed, other parts of the system are often orders of magnitude more expensive at those frequencies where performance matters. Where it gets the very high performance, is pillars/channels etched into silicon quite similar to how DRAM capacitors are made, just a “little bit bigger”. This allows for very low inductance and thus very high resonant frequency.
It is a special PCB laminate designed to create capacitance inside the PCB stack-up, typically between closely spaced power and ground planes.