A system , comprising: a gas turbine engine , comprising: a combustor section having one or more combustors configured to generate combustion products ; a turbine section having one or more turbine stages between an upstream end and a downstream end , wherein the one or more turbine stages are driven by the combustion products ; an exhaust section disposed downstream from the downstream end of the turbine section , wherein the exhaust section has an exhaust passage configured to receive the combustion products as an exhaust gas ; and a mixing device disposed in the exhaust section , the mixing device being configured to divide the exhaust gas into a first exhaust gas and a second exhaust gas , and to combine the first and second exhaust gases in a mixing region to produce a mixed exhaust gas , wherein the mixing device comprises: a first section configured to convey the first exhaust gas to the mixing region , wherein the first section comprises a lobe mixer having an annular sinusoidal shape with alternating first and second open-ended passages, the first open-ended passages being configured to direct a first portion of the first exhaust gas away from a longitudinal axis of the mixing device , and the second open-ended passages being configured to direct a second portion of the first exhaust gas toward the longitudinal axis ; and a second section configured to convey the second exhaust gas to the mixing region , wherein the second section circumferentially surrounds the first section . a combustor section having one or more combustors configured to generate combustion products ; a turbine section having one or more turbine stages between an upstream end and a downstream end , wherein the one or more turbine stages are driven by the combustion products ; an exhaust section disposed downstream from the downstream end of the turbine section , wherein the exhaust section has an exhaust passage configured to receive the combustion products as an exhaust gas ; and a mixing device disposed in the exhaust section , the mixing device being configured to divide the exhaust gas into a first exhaust gas and a second exhaust gas , and to combine the first and second exhaust gases in a mixing region to produce a mixed exhaust gas , wherein the mixing device comprises: a first section configured to convey the first exhaust gas to the mixing region , wherein the first section comprises a lobe mixer having an annular sinusoidal shape with alternating first and second open-ended passages, the first open-ended passages being configured to direct a first portion of the first exhaust gas away from a longitudinal axis of the mixing device , and the second open-ended passages being configured to direct a second portion of the first exhaust gas toward the longitudinal axis ; and a second section configured to convey the second exhaust gas to the mixing region , wherein the second section circumferentially surrounds the first section . a first section configured to convey the first exhaust gas to the mixing region , wherein the first section comprises a lobe mixer having an annular sinusoidal shape with alternating first and second open-ended passages, the first open-ended passages being configured to direct a first portion of the first exhaust gas away from a longitudinal axis of the mixing device , and the second open-ended passages being configured to direct a second portion of the first exhaust gas toward the longitudinal axis ; and a second section configured to convey the second exhaust gas to the mixing region , wherein the second section circumferentially surrounds the first section . <EOS>