On the ranges of bilinear pseudo-differential operators of $S_{0,0}$-type on $L^2 \times L^2

In this paper, the ranges of bilinear pseudo-differential operators of $S_{0,0}$-type on $L^2 \times L^2$ are determined in the framework of Besov spaces. Our result improves the $L^2 \times L^2 \to L^1$ boundedness of those operators with symbols in the bilinear H\"ormander class $BS^m_{0,0}$.