| 摘要 |
PURPOSE: To reduce the number of parts of a radio communication equipment, to reduce weight, to perform miniaturization and to lower power consumption. CONSTITUTION: By the changeover of an internal switch, a high frequency switch IC 30 connects a transmission part 10 or a reception part 20 through a band-pass filter 40 to an antenna 50. At the time of performing transmission by normal power, the transmission part 10 and the antenna 50 are connected. At the time of reception, the reception part 20 and the antenna 50 are connected and a reception operation is performed. In the case of attenuating and radiating transmission signals Sout, a state where the reception part 20 and the antenna 50 are connected is set. The transmission signal Sout corresponding to the transmission wave Ss of an intermediate frequency band is generated in a transmission mixer 11, a power amplifier 12 and an isolator 13 in the transmission part 10. The transmission signal Sout is attenuated for the isolation of the high frequency switch IC 30 and it is supplied to the side of the antenna 50 and radiated. That is, without using an attenuator or the like, the attenuated transmission signal Sout is obtained. |
