Initialization of a wireless clock distribution system using an external antenna

A compact wireless clock distribution system with an external planar array antenna which can provide phase uniformity suitable for synchronizing at 3 GHz over an area 4-5 /spl times/ larger than that previously thought possible is proposed. The system is composed of an off-chip antenna and multiple clock receivers distributed over an integrated circuit or over multiple IC's. The system has a comparable form factor as a system using conventional clock system. A technique to synchronize the receivers is proposed. The transmitter and receiver circuits required for the system have been fabricated in a 130-nm CMOS process. Using a transmitter, an amplitude modulated 17-GHz clock signal is generated and transmitted. The signal is picked up by a receiver and utilized to initialize/synchronize the receiver and to generate a local clock signal in the presence of a heatsink.