Sorry,
You will need a 4G modem to receive the SIM card and wireless data signal.
You will need a failover router so only your primary data (i.e. broadband) is used and then the 4G system is only used in the event of the primary data failing.
Some of the more expensive router will take the SIM card directly. These tend to be geared towards business and are overkill for our needs.
I did find this discussion here:
Sorry Im not more help right now, but Im still very early in my research.