As pointed out, the matrices can be obtained using Normal.
tfm = TransferFunctionModel[(2*s + 3)/(s^2 + 0.4*s + 1), s];
ssm = StateSpaceModel[tfm];
{a, b, c, d} = Normal[ssm];
MatrixForm /@ {a, b, c, d}
![enter image description here](https://community.wolfram.com//c/portal/getImageAttachment?filename=Screenshotfrom2023-02-1512-07-43.png&userId=29473)
State space representations are not unique. Matlab ordered the states differently. To get that result in this case, do
MatrixForm /@ Normal[StateSpaceTransform[ssm, {{0, 1}, {1, 0}}]]
![enter image description here](https://community.wolfram.com//c/portal/getImageAttachment?filename=Screenshotfrom2023-02-1512-07-58.png&userId=29473)