Traveling wave amplifier for driving optical modulator

Patent metadata

Field	Value
Publication number	US-9825709-B2
Application number	US-201615195422-A
Country	US
Kind code	B2
Filing date	Jun 28, 2016
Priority date	Jun 29, 2015
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

A traveling wave amplifier includes: a first line to transmit an input signal; an output-side line to transmit an output signal; amplifiers each having an input node and an output node, the input nodes being connected with the first line at first intervals and receiving the input signal, each of the amplifiers amplifying a signal input to the input node and outputting the amplified signal from the output node, the output nodes being connected with the output-side line at second intervals and generating the output signal; a second line to transmit another input signal having a phase opposite to a phase of the input signal; a first resistor having a first end connected with the first line and a second end; and a second resistor having a first end connected with the second line and a second end connected with the second end of the first resistor.

First claim

What is claimed is:

1. A traveling wave amplifier to amplify an input signal and output the amplified input signal as an output signal, comprising:
a first input terminal configured to receive the input signal;
a second input terminal configured to receive another input signal having a phase opposite to a phase of the input signal;
an output terminal configured to output the output signal;
a first input-side transmission line having a first end connected with the first input terminal and a second end, for transmitting the input signal;
a second input-side transmission line having a first end connected with the second input terminal and a second end, for transmitting the another input signal;
an output-side transmission line having a first end connected with the output terminal, for transmitting the output signal;
a plurality of amplification circuits each having an input node and an output node, the input nodes of the amplification circuits being connected with the first input-side transmission line at first intervals in a predetermined order and receiving parts of the input signal, each of the amplification circuits amplifying a part of the input signal input to the input node thereof and outputting an amplified signal from the output node thereof, the output nodes of the amplification circuits being connected with the output-side transmission line at second intervals in a predetermined order and generating the output signal;
a first resistive element having a first end connected with the second end of the first input-side transmission line and a second end; and
a second resistive element having a first end connected with the second end of the second input-side transmission line and a second end connected with the second end of the first resistive element.

2. The traveling wave amplifier according to claim 1 , wherein the second input-side transmission line includes capacitors and a transmission line, each of the capacitors having a capacitance substantially equivalent to a capacitance of the respective input nodes of the amplification circuits, the second input-side transmission line having a characteristic impedance substantially equal to a characteristic impedance of the first input-side transmission line and a delay substantially equal to a delay of the first input-side transmission line.

3. The traveling wave amplifier according to claim 2 , wherein the number of capacitors is equal to the number of amplification circuits and the capacitors are connected with the second input-side transmission line at the first intervals.

4. The traveling wave amplifier according to claim 1 ,
wherein the first input-side transmission line includes a first signal wiring line for transmitting the input signal, and a first ground wiring line adjacent to the first signal wiring line, the first input-side transmission line having a first distance between the first signal wiring line and the first ground wiring line,
wherein the second input-side transmission line includes a second signal wiring line for transmitting the another input signal, and a second ground wiring line adjacent to the second signal wiring line, the second input-side transmission line having a second distance between the second signal wiring line and the second ground wiring line, and
wherein the second distance is shorter than the first distance.

5. The traveling wave amplifier according to claim 1 , further including a termination capacitor,
wherein the second end of the first resistive element and the second end of the second resistive element are grounded through the termination capacitor.

6. The traveling wave amplifier according to claim 1 , wherein the plurality of amplification circuits is arranged in a row from the first input terminal and the second input terminal to the output terminal, the input node of each of the amplification circuits being connected with the first input-side transmission line according to the predetermined order and the row.

7. The traveling wave amplifier according to claim 1 ,
wherein each of the amplification circuits further includes an emitter follower and a single-ended amplification circuit for amplifying a single-ended signal,
wherein the single-ended signal is input to the input node and is input to the single-ended amplification circuit through the emitter follower, and
wherein the single-ended amplification circuit amplifies the single-ended signal input through the emitter follower and outputs the amplified signal from the output node.

8. The traveling wave amplifier according to claim 1 , further including: a differential amplification circuit configured to receive the input signal and the another input signal and output an amplified signal amplified from the input signal and another amplified signal amplified from the another input signal to the first input-side transmission line and the second input-side transmission line, respectively,
wherein the differential amplification circuit is between the first input terminal and the first end of the first input-side transmission line and between the second input terminal and the first end of the second input-side transmission line.

Assignees

• Sumitomo Electric Industries

Inventors

• Tatsumi Taizo

Classifications

• H03F3/605

  Distributed amplifiers · CPC title

• H04B10/516 Primary

  Details of coding or modulation · CPC title

• H03F3/55 Primary

  with semiconductor devices only · CPC title

• H04B10/505

  using external modulation · CPC title