Abstract: A method of verifying a fault of an inspection unit, an inspection apparatus, and an inspection system are disclosed. The method according to the present disclosure includes: providing a verification reference body which is formed on a frame attached to an inspection system; placing the inspection unit on the verification reference body; obtaining image data of the verification reference body through the inspection unit; verifying a fault of the inspection unit by extracting a movement error and height error of the inspection unit from the image data; and generating a verification result indicating the fault of the inspection unit.

Abstract: A method of verifying a fault of an inspection unit, an inspection apparatus, and an inspection system are disclosed. The method according to the present disclosure includes: providing a verification reference body which is formed on a frame attached to an inspection system; placing the inspection unit on the verification reference body; obtaining image data of the verification reference body through the inspection unit; verifying a fault of the inspection unit by extracting a movement error and height error of the inspection unit from the image data; and generating a verification result indicating the fault of the inspection unit.

Abstract: A method of verifying a fault of an inspection unit, an inspection apparatus, and an inspection system are disclosed. The method according to the present disclosure includes: providing a verification reference body which is formed on a frame attached to an inspection system; placing the inspection unit on the verification reference body; obtaining image data of the verification reference body through the inspection unit; verifying a fault of the inspection unit by extracting a movement error and height error of the inspection unit from the image data; and generating a verification result indicating the fault of the inspection unit.

Abstract: A differentially encoded quadrature modulation method comprises the steps of setting an index corresponding to a phase variation value constituted of input data, forming a phase value to obtain a phase-modulated output phase value from a given table and forming a channel signal to obtain in-phase (I) and quadrature (Q) channel signals from a given table using the phase value. The apparatus for performing the above comprises a signal converter for converting serially input data into two binary signal trains, a signal forming portion for obtaining channel signals, a digital-to-analog converter for converting the respective signals into two analog signals, a baseband filter for baseband-pass-filtering the signals, a phase shifter for shifting a carrier by 90.degree., first and second multipliers for multiplying the filtered signals with the carrier and phase-shifted carrier, respectively, and a mixer for mixing the respectively obtained signals and outputting a combined signal.