| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a frequency synthesizer suitable for fast switching which converts a low frequency signal into an output band signal of a higher frequency, and also expands the bandwidth by twice. SOLUTION: Two frequency signals with a 90 deg. phase difference which are outputted from a two-phase direct digital synthesizer 10 operating as a frequency signal generating means are given to 1st and 2nd balanced modulating means 14 and 16 one by one through a switching means 30. Also, two local oscillation frequency signals with a 90 deg. phase difference which are outputted from a local oscillating means 22 are given to the 1st and 2nd balanced modulating means 14 and 16 one by one. An output frequency of the synthesizer 10 is switched and set in accordance with a hopping pattern code outputted from a frequency hopping pattern code generating means 32 and also the means 30 is switched and controlled. An adding means 24 adds outputs of the means 14 and 16 and outputs an output band signal.</p> |
