4g Antenna for LB2120 4g modem

I have consulted the knowledge base article on external antenna (and have left a message there).  The article makes clear that Netgear will not be responsible for external antenna connected .... (which is reasonable)  but it does not give details of suitable antenna types.

So my question to the community?  I have recently bought a LB2120 , I am using it in a rural setting and in order to get a strong enough signal I will need to connect 2 external directional antenna.  I am proposing to use antenna with a folded dipole active element (plus balun).  These will present a 50 ohm impedence to the modem but a short at DC.  Will the modem accept this, as did the Huawei that I used before buying the 2120.

(I have not tried the telephone helpline because I suspect that the question is too technical and specific)