[SI-LIST] Re: Slot Antenna
- From: "Ibrahim Khan" <ikhan@xxxxxxxxxxxxxxxxxxx>
- To: "EVANS,JEFF (HP-Cupertino,ex3)" <jeff_evans@xxxxxx>
- Date: Sat, 27 Jul 2002 10:29:25 -0500
Jeff,
Thanks for your input. I do not have nay signals crossing the split.
The nearest ground is 2 signal layers away. My concern is that these
voltage islands sitting side by side may form a slot antenna and
radiate. Questions are:
1. How far apart these voltage islands should be from each other.
2. If decoupling capacitors along the two adjacent edges can help then
how far apart should the caps ber placed along the edge.
Thanks,
Ibrahim Khan
-----Original Message-----
From: EVANS,JEFF (HP-Cupertino,ex3) [mailto:jeff_evans@xxxxxx]=20
Sent: Friday, July 26, 2002 6:34 PM
To: Ibrahim Khan; si-list@xxxxxxxxxxxxx
Subject: RE: [SI-LIST] Slot Antenna
Ibrahim,
Besides the slot antenna which might be exacerbated by signals crossing
the split, or EM noise propagating from inside your PCA, it sounds like
you now also have two patch antennas (3.3 and 1.5). Actually, both of
these effects can be mostly mitigated with an underlying continuous
closely coupled ground plane (2 to 4 mils) and good high frequency
discrete decoupling capacitors sprinkled around both voltage planes.
-Jeff Evans
EMC Architect/Lead
Research and Development
Industry Standard Server Division
Hewlett Packard Company
-----Original Message-----
From: Ibrahim Khan [mailto:ikhan@xxxxxxxxxxxxxxxxxxx]=20
Sent: Friday, July 26, 2002 8:59 AM
To: si-list@xxxxxxxxxxxxx
Subject: [SI-LIST]=20
Hello SI Gurus,
=20
If we have a split plane with two different voltages on the splits (e.g
3.3 on one side and 1.5 on the other). Will it make a slot antenna.
=20
Thanks for any insight.
=20
Ibrahim Khan
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=20
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