Prediction and Verification of Power/Ground Plane Edge Radiation
Excited by Through-Hole Signal Via
Based on Balanced TLM and Via Coupling Model.
Jun So Pak, Junwoo Lee, Hyungsoo Kim, and Joungho Kim
Terahem Interconnection and Package Labxatory, Department of Electrical Engineaing and Computer
Science. Korea Advanced Institute of Science and Technology, 373-1 Kusong, Yusong, Daejeon 305-701, Korea.
Tel) +82-42-869-5458, Fax) +8242-869-8058
E-mail) cliitoonebminfo.kaist.ac.kr. flusu~’~~itlro.knist.ac.kr,
ABSTRACT - We introduce a modeling and simulation method to predict powedgmund plane
resonance and edge radiation coupled fmm.broken return current path of through-hole signal via. and
analyze the coupling and radiation mechanism. The approach is successfully verified with a series of
measurements with various plane conditions.
In recent high paformence digital systems, the clock frequency and its harmonics are continoously increased
over GHt range. At the m e time, the system density becomes higher, and then PCB and package have more
number of plane layers and more embedded signal traces, containing more thmugh-hole signal via and stripline.
Since these trends makes the PCB size be almost equal to wavelength of opting frequencies and, hence, the
radiated emission problem is more complicated and increased The radiakd anision problem of the high
performance digital system is too serious and difticult to be solved. Nevertheless, the radiated emission from
transmission line has been well and detailed analyzed so far. On the other band, the study on the pwer/ground
plane edge radiation problem has just started and expimentally investigated in a basic level approach. Since the
power/ground plane edge radiation has the many excitation sources, which are a large current swing U 0 driver
[l] well known as SSN (simultaneous switchmg noise) a n d the anbedded signal lrace in power/ground plane
(  [SI), the solving of the radiated emission is wholly depending on the settlement of coupling mechanism
between powerlground plane and the excitation sources.
However, these previous investigation overlooked the role of throughhole signal via, which are used for
layer transition of signal traces. The  assumed the &tion
free space [Z]. However the power/gmund plane is not transmission structure but cavity, which bas no travelmg
mves but standing waves. Therefore the exciting source of the pwer/gmund plane resonance and edge
radiation is not the current of through-hole signal via itself but the broken r e -
between different layas around the through-hole stgal via .
In this paper, we infxoduce a new modeling and simulation method to predict the pwer/ground plane
resonance and edge radiation based abalancBd TLM model and a detailed coupling via model to excite the plane
resonance. Based on the approach, we analyze the coupling mech” between the through-hole signal via and
the power/ground plane. Also we relate it to the relation between the edge radiation of the power/ground plane
and the rewnance of it And the truth that the origiaal source of the pwer/ground plane edge radiation is the
broken r e m current of through-hole signal via and verified With the model and the experimenfs. We have
successfully predicted the powedground plane edge radiation and it is well verified with a series of the
measurements with various power/ground plane conditions.
pattern of through-hole signal via is same as open
current, which has to jump
1 1 . Model and Simulation of Power/Ground Plane Edge Radiation
Excited by Through-hole Signal Via.
Firstly, we assume that the power/pmd plane has no AC current path like as &-coupling capacitor, and the
top, bottom layer microstrip lines which are connected with thmogh-hole signal via, have the ground plane,
power plane as return current path, respectively (Fig. 2). Therefore, when the input signal sent along with a
0-7803-812&9/03/$17.00 0 2003 lEEE