Patent ID: 9020071
Filing Date: 2015-04-28
Classification: H04B,H04L

Abstract:
1. An Amplitude-Shifted-Keyed (ASK) transmitter comprising: a first variable current source for sourcing a first current to a combining node in response to a first carrier-wave signal; a second variable current source for sinking a second current from the combining node in response to a second carrier-wave signal; a first fall-enhancement switch for sourcing a first enhancement current to the combining node in response to a first enhancement signal; a second fall-enhancement switch for sinking a second enhancement current from the combining node in response to a second enhancement signal; a data input and a carrier-wave input, the carrier-wave input having a carrier signal with a higher frequency that a data rate of the data input; and control logic that receives the carrier-wave input and generates the first carrier-wave signal and the second carrier-wave signal each having a carrier wave with a same frequency as the carrier signal of the carrier-wave input; the control logic also generating the first enhancement signal in an inactive state that disables the first fall-enhancement switch from sourcing the first enhancement current when the data input is in a second state, the control logic generating the first enhancement signal having the carrier wave to enable the first fall-enhancement switch to source the second current when the data input is in a first state; the control logic also generating the second enhancement signal in an inactive state that disables the second fall-enhancement switch from sinking the second enhancement current when the data input is in the second state, the control logic generating the second enhancement signal having the carrier wave to enable the second fall-enhancement switch to sink the second current when the data input is in the first state; wherein the control logic drives the carrier wave to the first fall-enhancement switch and to the second fall-enhancement switch when the data input is in the first state, but disables the first fall-enhancement switch and to the second fall-enhancement switch when the data input is in the second state, wherein an amplitude of an envelope of the combining node is reduced when data input is in the second state.