INTRODUCTION
Integrated circuits have been widely used with the rapid development of
industrial technology and the continuous increase in people’s demand for
electronic products. As a necessary interconnection structure in
integrated circuits, the crosstalk has become an important factor
restricting the further development of integrated circuits. Therefore,
the effect of crosstalk between coupled microstrip lines on integrated
circuits must be investigated.
The spacing between the microstrip lines is extremely small due to the
high integration requirements of integrated circuits and is easy to
cause EM coupling between the microstrip lines, thereby forming
crosstalk [1]. To adapt to the development trend of integrated
circuits, research scholars at home and abroad have explored methods to
reduce crosstalk. They analyze the formation principles and influencing
factors of crosstalk between two or more transmission lines [2] and
use them as the theoretical basis to develop methods for reducing
crosstalk. In accordance with the principle of crosstalk formation,
further analysis shows that increasing the transmission line spacing is
an effective method to reduce crosstalk [3]. Although this method
has better ability to suppress crosstalk, it wastes considerable limited
wiring space and does not conform to the development direction of
integration. In [4,5,6], the crosstalk is reduced by placing a
via-stitch guard or a serpentine guard trace between multiple
transmission lines, and the effect of crosstalk suppression is analyzed
by EM simulation. Although it has a certain suppression effect on the
crosstalk, it affects the wiring method to a certain extent. Resonance
problems may also occur. In actual application, the protection line
needs to be analyzed and designed separately, which increases the design
cost, does not have wide applicability, and is difficult to promote. In
[7], the microstrip line structure is covered with a graphene
coating, and the crosstalk is reduced by depositing a covering
dielectric layer. This method causes the transmission power to be
absorbed by the coating to a certain extent, and the use of graphene
deposition layers requires higher production costs. In [8,9,10], the
method of changing the physical form of the transmission line by
inserting rectangular slots for the transmission line or using steeped
transmission line is used to reduce the crosstalk. The essence is to
reduce the crosstalk by changing the capacitive coupling and inductive
coupling ratio. The disadvantage of this method is that the far-end
crosstalk reduction effect is not ideal, and the maximum crosstalk
suppression effect is only 6 dB for some stepped structures. In
[11], a specific DMS is etched on the microstrip line to achieve
crosstalk reduction. However, this S-shaped structure design is
extremely complicated, the etching is extremely difficult, and the
crosstalk suppression effect is limited.
On the basis of the DMS research of [11], this paper designs a
TL-shaped DMS, which has a simple structure and is easy to apply in
practice. The TL-shaped DMS has a better suppression effect on the
far-end crosstalk in the 0–8 GHz frequency band while improving the
insertion loss of adjacent microstrip lines, and guaranteeing the signal
transmission performance of its own microstrip lines compared with the
S-shaped DMS. The proposed method is simulated and verified through
theoretical analysis and full-wave EM simulation, using HFSS (a full
wave 3-D EM Simulation tool from Ansoft Corporation). Compared with the
ordinary coupled microstrip line that does not use this method, the
effect of this method on crosstalk suppression is quantified, and its
effectiveness is proved. The comparison of measured results of samples
and simulation results shows that they are in good agreement, indicating
that the proposed method has practical application value and good
results.