APPARATUS FOR EVASION IN BAND SPURIOUS OF SPECTRUM ANALYZER AND METHOD THERE OF

摘要

An apparatus and a method for evading an in band spurious of a spectrum analyzer are provided to enhance a performance of a phase fixing loop by evading the in band spurious by moving a start frequency to a section without the in band spurious. A first phase fixing loop(10) includes a frequency analyzer(11), a loop filter(12), a voltage control oscillator(13), a mixer(14), and a frequency demultiplier(15). A sampling mixer(20) multiplies a variable frequency 8-de-multiplied by the first phase fixing loop by several~several tens. A second phase fixing loop(30) converts a reference frequency to be locked into a middle frequency and then compares the middle frequency with the several~several tens-multiplied frequency. A controller(40) outputs a control order to the first and second phase fixing loops. A central processing device(50) operates a position of a spurious with a spurious generation evading algorithm predetermined in the controller and changes the reference frequency, thereby to evading the spurious.