#RF experts, I need your advice!

I live in the middle of dense bushland and am dependent on #4g for my #internet. I am using a Cel-Fi GO G41 repeater with an 18dbi LDAP yagi #antenna. The nearest cell tower is roughly 30km away. On the wave app, it shows that cell tower receive quality is low/poor. I would like to improve this if possible. I'm not too knowledgeable about RF #signals and antennas but my understanding is that a different antenna may help. Can someone advise?
#radio #technology