Differential Microstrip and Slot-Ring Antennas for Millimeter-Wave Silicon Systems

Differential on-chip microstrip and slot-ring antennas with a quartz superstrate are presented for wafer-scale silicon systems. The antennas are fed at the nonradiating edge, which is compatible with differential coupled-lines, and are built on a 0.13-μ m CMOS process with a layout that meets all the metal density rules. A high radiation efficiency is achieved using a 100- μm quartz superstrate placed on top of the silicon chip. Both antennas have a measured gain varies from about 2 to 3 dBi at 91-94 GHz, with a - 10-dB
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bandwidth of 7-8 GHz and a simulated radiation efficiency of >;50%. The designs are compatible with single- and multielement transceivers, and with wafer-scale imaging systems and power-combining arrays.