Development of Eliminating the Effect of Clutter Signal in Vital Signals Radar by Using Hardware Circuits

Three novel structures of non-contact vital signal radars that can eliminate the DC offsets, which are caused by clutter signals and LO leakage, will be developed in this project. All of vital signal radars are composed of antenna、low noise amplifier、single balance mixer and phase shifter, but three different radars will adopt different kinds of hardware circuits and methods to eliminate the DC offsets to obtain better detection of the vital signals of a target located at any point within the detectable range. The first type of vital signal radar will modify the adaptive DC compensation circuit proposed in the previous work to rapidly determine the appropriate DC compensation values that can detect the vital signals in different testing situation. The second structure of vital signal radar will develop an automatic phase detection circuit to achieve the phase of the clutter signal and LO signal to be just in (or out of) phase, thus no DC offset voltage will be converted to the output of mixer. The last configuration of the radar is the non-feedback feature that can determine the required compensation voltages that are applied to the differential inputs of base-band amplifier of the vital signals radar. All of the proposed structures will be fabricated on the PCBs to verify the proposed methods. The measurement will be done to verify the proposed radars that are able to detect the vital signals of a target located in any points within the detectable distance.

Project ID:PB10707-0410
External Project ID:MOST107-2221-E182-028