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Design >> RF Design >> Package Inductance for 10 GHz range operation
https://designers-guide.org/forum/YaBB.pl?num=1317827632

Message started by Ricky Chen on Oct 5^th, 2011, 8:13am

Title: Package Inductance for 10 GHz range operation
Post by Ricky Chen on Oct 5^th, 2011, 8:13am

Dear friends,

Can anybody tell the best package available for 10 GHz RF signal operation ?
The lowest inductance is desirable. Bondwire inductance can be reduced for smaller package but what about LEAD inductance ?
What PCB material should be used and what is the constraints on PCB trace for proper operation at 10 GHz?

Title: Re: Package Inductance for 10 GHz range operation
Post by rfcooltools.com on Oct 10^th, 2011, 11:10pm

Ricky-chen,

if price is no option when a flipped chip on rodger4003 substrate will probably be pretty good.

More practically what kind of signals are these 10GHz are they tones or are they broad band up to 10GHz. The reason I inquire is that the answer to this will determine if a low impedance at high frequency is needed or if the impedance at high frequency of a bondwire can be resonated or transformed into something more benign.

http://rfcooltools.com

Title: Re: Package Inductance for 10 GHz range operation
Post by Ricky Chen on Oct 11^th, 2011, 6:27am

Thanks for your reply
It is Broad Band. I think tuning is not perhaps an option.
By the way what is the cost of rodger4003 substrate ?
What it actually helps ?

-Ricky

Title: Re: Package Inductance for 10 GHz range operation
Post by rfcooltools.com on Oct 28^th, 2011, 10:09pm

Ricky Chen,
rogers is about 5 to 10 time more expensive than fr4.
Its controlled under tighter process parameters more predictable t-lines and even strip-line filters epsilonR is different and is stable over temp. You can make do with fr4 depending on your application.

http://rfcooltools.com

Title: Re: Package Inductance for 10 GHz range operation
Post by loose-electron on Oct 29^th, 2011, 11:57am

QFN packages are commonly used up to 5GHz, and perhaps are viable to 10GHz.

Need to look at the package model and determine the reactive elements.

chip on board with a specialty dielectric are another possible but if you want a typical chip in package on pcb i would look at the QFN

Title: Re: Package Inductance for 10 GHz range operation
Post by Ricky Chen on Nov 16^th, 2011, 5:19pm

Thanks loose-electron,

Can you tell us the cost of Chip on board. I mean how much costlier it will be than the FR4 PCB.

I think one can also mount all discrete components on Chip on board.

Do you think FR4 PCB with QFN package will work well till 5 GHz.

Title: Re: Package Inductance for 10 GHz range operation
Post by loose-electron on Nov 16^th, 2011, 9:39pm

keep the traces short and include the board parasitics in your model and hit the simulate button!

Title: Re: Package Inductance for 10 GHz range operation
Post by Ricky Chen on Nov 16^th, 2011, 9:44pm

loose-electron wrote on Nov 16^th, 2011, 9:39pm:

keep the traces short and include the board parasitics in your model and hit the simulate button!

Simulate button for what simulation ?

Can you mention something more about Chip on Board if u have experienced using that

Title: Re: Package Inductance for 10 GHz range operation
Post by loose-electron on Nov 18^th, 2011, 9:02am

the parasitics of your board, the traces on the board, the RLC of the package can all be included into your simulation to determine if the methods proposed will work at the desired frequency.

You need to look up the coefficients of capacitance and inductance for the proposed PCB material and estimate those components in a simulation.