ROA-brick topology for rotary resonant clocks

This paper presents a topology design-based solution that addresses one of the major challenges in the design of Rotary Traveling Wave Oscillator (RTWO) based clock networks-the direction of oscillation. A “rotary oscillator array (ROA) brick” structure is proposed that guarantees the consistency of the rotation direction of the traveling signals on all the RTWO rings in an ROA. The ROA built from ROA bricks has the following advantages: (1) The same phase point of all the RTWO rings in the array can easily be tracked, (2) The same phase points of the ROA are independent of the specific rotation direction of the traveling signals on the ROA. SPICE simulations demonstrate these advantages of the brick-based ROA circuit design in establishing the directional consistency of the RTWO rings.