| 摘要 |
PROBLEM TO BE SOLVED: To provide a spurious interference wave measuring instrument capable of measuring the spurious characteristics of the selective call signal receiver of a direct conversion system. SOLUTION: This instrument is provided with an encoder 1 transmitting a call signal, a desired wave generation means 2 generating a desired wave, a spurious interference wave generation means 3 generating a spurious interference wave and a cell box 5 radiating the radio wave of the signal generated from these means in the space interrupting external noise. At this time, the device is provided with a low-pass filter 4 attenuating the higher harmonic of the spurious interference wave generated by the spurious interference generation means 3 and a spectrum analyzer 6 to be used for adjusting the characteristics of this low pass filter. Since the higher harmonic is suppressed, the spurious characteristics of the selective calling signal receiver of a direct conversion system can exactly be measured. |
