Title :
An alignment insensitive separable electromagnetic coupler for high speed digital multidrop bus applications
Author :
Benham, J.R. ; Amirtharajah, R. ; Critchlow, J. ; Simon, T. ; Knight, T.F., Jr.
Author_Institution :
Intel Desktop Platform Archit. Group, Hudson, MA, USA
Abstract :
A separable electromagnetic coupler was designed, simulated, fabricated, and tested as part of a prototype eight module multidrop memory bus running at 1.6 Gb/s per differential pair. The coupler consists of broadside coupled traces, one on a rigid motherboard and the other on a flex circuit soldered to a daughter card. The zigzag geometry of the traces reduces variation in coupling coefficient due to horizontal and vertical misalignment of the coupler halves. Simulation and testing indicates that a target capacitive coupling coefficient of 0.34, which has been selected to balance signal transmission level requirements against motherboard impedance discontinuity effects, can be achieved with little variation over +/- 12 mil alignment tolerance.
Keywords :
CMOS digital integrated circuits; S-parameters; electromagnetic coupling; high-speed integrated circuits; intersymbol interference; microstrip lines; printed circuit accessories; system buses; 1.6 Gbit/s; CMOS logic process; alignment insensitive separable electromagnetic coupler; alignment tolerance; broadside coupled traces; capacitive coupling coefficient; coupling coefficient variation reduction; daughter card; eight module multidrop memory bus; flex circuit; full custom differential receiver circuit; high speed digital multidrop bus applications; horizontal misalignment; intersymbol interference; microstrip lines; motherboard impedance discontinuity effects; rigid motherboard; signal transmission level requirements; vertical misalignment; zigzag geometry; Circuit simulation; Coupling circuits; Electromagnetic coupling; Flexible electronics; Geometry; Impedance; Intersymbol interference; Optical coupling; Optical reflection; Transmission lines;
Conference_Titel :
Microwave Symposium Digest, 2003 IEEE MTT-S International
Conference_Location :
Philadelphia, PA, USA
Print_ISBN :
0-7803-7695-1
DOI :
10.1109/MWSYM.2003.1212575
