Patents Assigned to TTP Communications Limited
  • Patent number: 7224948
    Abstract: There are provided a transmitter and a wireless communication terminal apparatus using the same for solving a problem of undesired spurs due to harmonics of an output signal of a frequency synthesizer, and further solving a problem of the undesired spurs occurring when the harmonics of an output signal of a crystal oscillator are mixed into a VCO to facilitate to design a circuit or a mounting substrate. The transmitter has a relationship between an output frequency of a PLL frequency conversion circuit (5) and output frequencies of frequency synthesizers (1, 2) stored therein, and the output frequencies of the frequency synthesizers (1, 2) input into the PLL frequency conversion circuit (5) are controlled on the basis of the relationship so that the undesired spurs are suppressed.
    Type: Grant
    Filed: January 11, 2000
    Date of Patent: May 29, 2007
    Assignees: Hitachi, Ltd., TTP Communications Limited
    Inventors: Taizo Yamawaki, Satoshi Tanaka, Masaru Kokubo, Kazuo Watanabe, Masumi Kasahara, Kazuaki Hori, Julian Hildersley