Patent ID: 6343221
Filing Date: 2002-01-29
Classification: H04B

Abstract:
A digital portable telephone device in which frequency-division multiple access is carried out by using a signal within one of an analog frequency band and a digital frequency band, comprising:a receiver section for receiving a signal within one of an analog receiving frequency band and a digital receiving frequency band, wherein a received signal is converted into one of a digital-band first intermediate-frequency signal and an analog-band first intermediate-frequency signal by using a first local signal; a transmitter section for transmitting a signal within one of an analog transmitting frequency band and a digital transmitting frequency band, wherein a modulation signal is generated by using the first local signal; and a radio-frequency local signal generating section for generating the first local signal within one of a digital local signal frequency band and an analog local signal frequency band, and for supplying the first local signal to one of the receiver section and the transmitter section; wherein said receiver section requires only a single second mixer and a single second intermediate-frequency filter for down-conversion of the received signal frequency into one of the digital-band intermediate frequency and the analog-band intermediate frequency, said second mixer converting a selected one of the digital-band first intermediate-frequency signal and the analog-band first intermediate-frequency signal into a second intermediate-frequency signal by using a second local signal.