US 12,489,404 B2
Transmission interface and transmitter
Tadashi Minotani, Tokyo (JP); Toshiki Kishi, Tokyo (JP); Masatoshi Tobayashi, Yokohama (JP); Yoshikazu Urabe, Yokohama (JP); and Nobuhiro Toyoda, Yokohama (JP)
Assigned to NTT, INC., Tokyo (JP); and NTT INNOVATIVE DEVICES CORPORATION, Yokohama (JP)
Appl. No. 18/550,755
Filed by NTT, Inc., Tokyo (JP)
PCT Filed Mar. 25, 2022, PCT No. PCT/JP2022/014542
§ 371(c)(1), (2) Date Sep. 15, 2023,
PCT Pub. No. WO2022/203058, PCT Pub. Date Sep. 29, 2022.
Claims priority of application No. 2021-051318 (JP), filed on Mar. 25, 2021.
Prior Publication US 2024/0160236 A1, May 16, 2024
Int. Cl. H03F 1/26 (2006.01); H03F 1/30 (2006.01)
CPC H03F 1/26 (2013.01) [H03F 1/301 (2013.01); H03F 2200/18 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A transmission interface comprising:
a plurality of transmitters, each of the plurality of transmitters comprising:
a power supply terminal which is common to the plurality of transmitters, and configured to receive a first voltage;
a bias terminal configured to receive a second voltage;
a signal terminal configured to receive a signal voltage;
a power supply fluctuation inverting bias circuit to which the first voltage and the second voltage are applied, the power supply fluctuation inverting bias circuit being configured to make a fluctuation in the first voltage in opposite phase and output an inverted-phase fluctuation in the first voltage;
a modulating circuit to which the output of the power supply fluctuation inverting bias circuit and the signal voltage are applied, and configured to output an output which corresponds to the signal voltage and in which the fluctuation in the first voltage is superimposed in phase; and
a laser diode to which the first voltage and an output of the modulating circuit are applied, wherein
the power supply fluctuation inverting bias circuit includes
a resistor having a terminal connected to the power supply terminal, and
a fluctuation inverting transistor having a source connected to ground, a drain connected to the other terminal of the resistor, and a gate receiving the second voltage and the inverted-phase fluctuation in the first voltage; and
the modulating circuit includes
a modulating resistor having one of the ends connected to ground; and
a modulating transistor having a gate connected to the other end of the resistor and the drain of the fluctuation inverting transistor, a source connected to ground, and a drain connected to the other end of the modulating resistor, and configured to output the output of the modulating circuit.