According to some embodiments, there is provided a signal generating device, including a signal generator and a local signal generating unit. The signal generator generates a signal of a fixed frequency. The local signal generating unit generates, based on the signal of the fixed frequency, a first local signal to convert a frequency of a first signal, and a second local signal to convert a frequency of a second signal. The second signal is a signal resulting from that the first signal is subjected to frequency conversion based on the first local signal and has a frequency different from the first local signal.