r[x_,y_]:=(Sqrt[(x^2)+(y^2)]);
d=1.5;
Q=1;
Phi[x_,y_]:=(Q/(r[x+d,y]))+((-0.2Q)/(r[x-d,y]))
Ex=- D[Phi[x,y], x];
Ey=-D[Phi[x,y], y];
Lx=6;
Ly=3;
VectorPlot[{Ex,Ey},{x,-Lx,Lx},{y,-Ly,Ly},VectorPoints->{24+1,12+1},VectorScale->0.08,FrameTicks->None,Frame->None,AspectRatio->0.5]
StreamPlot[{Ex, Ey},{x,-Lx,Lx},{y,-Ly,Ly},StreamPoints->25,StreamStyle->{Black,Arrowheads[{{0.04, 0.5}}]},StreamScale->Full,FrameTicks->None,Frame->None,AspectRatio->0.5]