Patent ID: 9136948
Filing Date: 2015-09-15
Classification: H04B,H04L

Abstract:
1. An apparatus comprising: a plurality of input signal lines each configured to receive a binary input signal having a first value or a second value; an output signal line; and a plurality of amplifier stages each connected between one of the plurality of input signal lines and the output signal line and each configured to produce, based on the binary input signal at the respective input signal line, an output voltage on the output signal line of either a first level when the binary signal is at the first value or a second level when the binary signal is at the second value such that the output voltages of the respective plurality of amplifier stages collectively produce a summed analog output voltage on the output signal line at two or more discrete voltage levels each configured to drive an optical modulator, wherein a number of the two or more discrete voltage levels of the summed analog output voltage depends on a number of the plurality of amplifier stages connected in parallel with each other, wherein each of the plurality of input signal lines is connected to at least two of the plurality of amplifier stages, and wherein each of the plurality of amplifier stages is made active or inactive based on a value of the binary input signal at the respective input signal line in order to produce the two or more discrete voltage levels.