AMPLITUDE EQUALIZER FOR CELLULAR PHONE RELAY AMPLIFYING DEVICE

摘要

PROBLEM TO BE SOLVED: To obtain an amplitude equalizer which reduce intra-band deviation of a selection characteristic of an occupied frequency band in a relay amplifying device for a portable telephone and also makes attenuation gradient steeper. SOLUTION: A two-terminal pair circuit network is cascaded to an IF filter, an HPF part is provided as a serial circuit between an input terminal and an output terminal and an LPF part is provided as a parallel circuit between the output terminal and an earth. Serial resonance and parallel resonance of the HPF part equalize the amplitude deviation of an upper end part of a band to be selected and make an attenuation gradient steep. Serial resonance and parallel resonance of the LPF part equalize the amplitude deviation of a lower end portion of the band to be selected and make an attenuation gradient steep.