Patents by Inventor Kazuhisa Haeiwa

Kazuhisa Haeiwa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Digital amplitude modulation amplifier and television broadcasting machine
    Patent number: 6041082
    Abstract: Since output voltage e of coupler CU2 is displaced in phase by -135 degrees from input signals c and d (by -270 degrees from signals a and b), a carrier which makes signal f is phase shifted by -270 degrees by phase shifter .phi.1 so that signal f may have the same phase as signal e. Signal f and signal e are power composed by first 3 dB coupler M1, and are further phase shift controlled by variable phase shifters PH11 and PH12 so that they may have the same phase. Further, an output signal of variable phase shifter PH11 is phase shifted by -90 degrees by phase shifter SH1 so that it has a phase difference by 90 degrees from an output signal of variable phase shifter PH2, and the two signals controlled in this manner are inputted to 3 dB coupler M2. Consequently, two signals e and f inputted to the amplifier are all outputted as output voltage EOUT.
    Type: Grant
    Filed: September 4, 1997
    Date of Patent: March 21, 2000
    Assignees: NEC Corporation, Nippon Hoso Kyokai
    Inventors: Haruo Takeda, Yukio Tatsumi, Ikuji Fujitani, Takuya Shioda, Tomofumi Yoshimi, Tomohiko Sugimoto, Kazuhisa Haeiwa