Signal on Vodafone Mobile Broadband

At present my husband uses mobile broadband via Vodafone for watching soccer using NOW TV, the signal varies from 2 to 3 bars in our house in South Co Dublin. This affects quality of picture.
Is there a way of improving signal - what equipment or accessories would help, e.g. external antenna, extender, router ... we’re not too much into technology ...thanks in hope.

Is the SIM in a mobile phone, or do you have a dedicated modem the SIM is in? If it's a modem there is often a port to add an external antenna, these range from small antennas you can stick to a window right up to the likes of this https://www.satellitetv.ie/4g-lte-external-aerial thta can go in the attic or on a wall/chimney.

Are there no wired broadband connections available in your area?

Might be of interest, but ComReg legalised some of the mobile repeaters to allow for improvements in indoor coverage.