Sien-Chang C Liu

Title: Innovations of Sien-Chang C Liu

Introduction

Sien-Chang C Liu is a notable inventor based in Brea, California, recognized for his contributions to radar technology and signal processing. With a total of six patents to his name, Liu has made significant advancements in the field, particularly in developing methods to enhance radar performance in challenging environments.

Latest Patents

Liu's latest patents include an "Adaptive Doppler Filter Re-Optimization Method for Pulsed Interference Countermeasure." This invention involves a range-gated Doppler radar designed to mitigate the effects of pulsed interference. The Doppler filter is constructed using a vector of weights, calculated as the matrix product of the inverse of a reduced overall covariance matrix and a reduced progressive phasor vector. The reduced overall covariance matrix is formed by removing rows and columns corresponding to pulses affected by pulsed interference. The reduced progressive phasor vector is created by deleting elements corresponding to these corrupted pulses. The elements of the progressive phasor vector maintain a constant modulus, with their phases changing linearly within the vector. The overall covariance matrix is a weighted sum of an identity matrix and several specific covariance matrices, which may represent distributed clutter with both positive and negative velocities, as well as ground clutter.

Another significant patent is for "Methods and Apparatus for a Self-Calibrated Signal Injection Setup for In-Field Receive Phased Array Calibration System." This invention provides a calibration system