| 摘要 |
PROBLEM TO BE SOLVED: To miniaturize the device, to make it light and also to improve receiving wait time by switching oscillation frequencies of both or either of an RF band synthesizer and an IF band synthesizer at the time of sending and receiving in each used band. SOLUTION: A signal that is outputted from a mixer is used as a sending carrier at the time of sending, and an output from an RF synthesizer 12 is used as a 1st local signal for receiving and an output from an IF band synthesizer 8 is used as a 2nd local signal for receiving at the time of receiving. Also, an oscillation frequency of both or either the synthesizers 12 and 8 are switched at the time of sending and receiving in each used band. Thus, it is possible to send and receive in two bands with only two synthesizers by switching the oscillation frequencies of both the synthesizers 8 and 12 at the time of sending and receiving in both bands. Then, it is possible to use two frequency bands with a simple configuration and to improve receiving wait time. |
