| 摘要 |
PROBLEM TO BE SOLVED: To provide a wireless receiver which in-phase synthesizes intermediate frequency signals between two receiving systems, and prevents a rapid level change when disconnecting either of them to avoid error occurrence. SOLUTION: The wireless receiver has variable attenuators 5a and 5b which are compatible with two receiving systems that are connected to a pre-step of an in-phase synthesizing circuit 6 that in-phase synthesizes intermediate frequency signals, a receiving system selection switch part 14 which selects a receiving system that is to be disconnected, a voltage hold circuit 12 which detects a received signal level of the receiving system selected by the receiving system selection switch part 14 through a level detector 11 to hold it, and a control voltage generator 13 which outputs an initial attenuation control voltage corresponding to the received signal level held by the voltage hold circuit 12 and inputs an attenuation control voltage that is changed to the maximum attenuation control voltage according to a specified time passing into the variable attenuator compatible with the receiving system that is selected by the receiving system selection switch part 14. COPYRIGHT: (C)2009,JPO&INPIT
|
