Timing generator breaks clock speed limits in circuits using time folding and interpolating technique

Everything from quantum computing and pulsed imaging techniques to medical diagnostics requires precise timing pulses for the high degree of fidelity required in their measurements and event correlations. Typically, arbitrary timing generators create user-defined pulses with a specified resolution, usually limited to the clock speed in a circuit. This has a realistic limit of approximately 10 gigahertz, equivalent to 100 picoseconds. Realizing finer resolution than this in event timing requires circuit topologies that go beyond the nominal clock speeds.

New research reported in the Review of Scientific Instruments uses a novel approach of time folding and interpolation to break clock speed limits for arbitrary timing generators. In the approach, the authors created a circuit that combines multiple signals from clocks and pulse modulators that operate at different delays. Then, the signals are overlapped (or folded) to obtain finer discretizations in the resultant signal. These new points in the signal act as regions where the timing pulse can be generated and tailored to specific values within a new, smaller resolution.

The main contribution of this approach is to improve the timing resolution limits down to 5 picoseconds using the developed time folding process. This can fundamentally change the field for applications requiring precise knowledge of event timing. Once the pulse has been triggered, the pulse width can be varied over 10 orders of magnitude between 5 nanoseconds and 10 seconds. After the pulse has ended, a new pulse can be initiated after the 5 picosecond resolution window.

While this new hardware solution is significant, the authors note that the device stability does depend on temperature, so future work will focus on temperature compensation methods, since temperature in circuitry can vary over its operation.

Source: “A pico-second resolution arbitrary timing generator based on time folding and time interpolating,” by Xi Qin, Wen-Zhe Zhang, Lin Wang, Yu Tong, Heng Yang, Ying Rui, Xing Rong, and Jiang-Feng Du, Review of Scientific Instruments (2018). The article can be accessed at https://doi.org/10.1063/1.5037841 .