The Keysight (formerly Agilent) 1158A active probe offers R & D engineers the performance they need to probe small geometries in hard-to-reach areas on the DUT. These probes were designed specifically for the Infiniium 54800 Series oscilloscopes. As the speeds in designs increase, there may be more overshoot, ringing, and other perturbations when connecting an oscilloscope probe. Probes form a resonant circuit where they connect to the device. If this resonance is within the bandwidth of the oscilloscope probe being used, it will be difficult to determine if the measurement perturbations are due to the circuit or the probe. This probe has overcome the resonance formed by the connection of a probe to a device.