Title:
RADIO COMMUNICATION EQUIPMENT
Document Type and Number:
Japanese Patent JP3242337
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To reduce the number of synthesizers, to miniaturize a wireless portable telephone set, to reduce cost and to reduce power consumption by switching the oscillation frequency of each of synthesizers of RF band and IF band at the time of transmitting and receiving, respectively.
SOLUTION: In a double super heterodyne wireless communication equipment of, for example, 940MHz in transmitting frequency and 810MHz in receiving frequency, at the time of transmitting, 405.45MHz oscillated by the IF band synthesizer 8 and 534.55MHz oscillated by the RF band synthesizer 12 are mixed by a mixer 10, the mixed signal is passed a BPF 9 and inputted to a transmission system circuit 13 as targeted 940MHz. At the time of receiving, the oscillation frequency of the synthesizer 12 is switched to 810.45MHz, it is mixed with 405.45MHz of the output of the synthesizer 8, the mixed signal is passed the BPF 9 to take out 1215.9MHz, and it is mixed with the receiving RF signal 810MHz by a mixer 3. Then, 405.9MHz is taken out by the BPF 4 from that, the taken-out signal is mixed with 405.45MHz of the output of the synthesizer 8 to obtain 450kHz of the 2nd IF signal, and the obtained signal is inputted to a demodulating circuit 7.
Inventors:
Tadashi Shimonabe
Tetsuo Onodera
Tetsuo Onodera
Application Number:
JP31160396A
Publication Date:
December 25, 2001
Filing Date:
November 22, 1996
Export Citation:
Assignee:
Sharp Corporation
International Classes:
H04B1/44; H04B1/26; (IPC1-7): H04B1/44; H04B1/26
Domestic Patent References:
| JP918378A | ||||
| JP9232993A | ||||
| JP8223073A |
Attorney, Agent or Firm:
Takaya Koike