US 12537545 B2 / Jan 27, 2026

Variable-rate true-time delay filter

Systems, methods and devices are disclosed for a variable-rate true-time delay (VR-TTD) decimator for receiving an input data signal and providing an output decimated signal. The VR-TTD decimator may comprise: a VR-TTD decimator input for receiving the input data signal; and a VR-TTD decimator output for outputting the output decimated signal; a numerically controlled oscillator (NCO) for receiving a time delay control signal and a desired rate signal and for controlling coarse filtering, fine filtering and decimation of the input data signal; and an accumulator for generating the output decimated signal, wherein the accumulator comprises a plurality of shift registers, controlled by the NCO. The system may comprise a beamformer for providing an output signal coherently summed from a plurality of paths, where each path comprises a VR-TTD decimator for providing VR-TTD to the respective signals of the plurality of paths.