Looking to use an external 4g/5g antenna but unsure whether to get Omnidirectional or Unidirectional?

When installing an external antenna for use with 4g or 5g data a common question is asked which is the best type of antenna to get – omnidirectional or unidirectional.

The answer is, it all depends on your location and situation in relation to the local mast(s).

What are the difference between the two?

Although in many cases they look the same, there are differences in how they work, these mainly being how they pick the mobile signal up. The best analogy for this would be comparing a candle to a torch with the omni being a lightbulb and the uni being a torch.

Omnidirectional

An omnidirectional antenna picks its signal up from local towers in a 360 degree direction, the same way that a lightbulb shines its light in all directions around it. However, like a lightbulb does’n’t give the strongest light, the omnidirectional antenna has lesser gains and lesser distance than a unidirectional.

Pros

• Picks up signal in a 360 degree direction, if a tower fails then it can automatically switch to an alternative local tower.
• Ideal for areas with multiple towers in urban/suburban areas where there is already a reasonable signal outdoors.

Cons

• May pick up more interference
• Not ideal for areas where the signal is weak or distance to a tower is further
• Lower gain (2-6dbi)

Unidirectional

A unidirectional antenna picks its signal up from local tower in one narrow direction and therefore has to be pointed towards the tower providing that signal, the same way a torch only lights up the direction it is pointed in. However, like the torch which can only light up in one direction but has a stronger beam than a lightbulb, the unidirectional antenna has a stronger gain than an omnidirectional one.

Pros

• More focussed from one direction
• Less interference
• Higher gain (8-15dbi)
• Ideal for rural/countryside locations or where the tower is further away

Cons

• Needs to be aimed carefully at the tower with reasonable line of sight
• Can only pick up from one tower at once
• Need to be realigned to another tower should one tower not be working

Rule of thumb when choosing:

Choose Omnidirectional if:

• Your typical signal strength outside is 3-4 bars and you are not far from a tower
• You signal is pretty good but you want better stability
• You are likely to be changing your location regular i.e. a motorhome or touring caravan

Choose Unidirectional if:

• Your typical signal strength outside if 1-2 bars or you are a little further away from a tower or in a rural location
• You know the location of the tower and have a reasonable line of sight to the area it is located
• The location of your antenna is not going to keep changing

So what is best for me?

Whether you wish to use 4g or 5g, the first thing to do check is existing coverage in your area and locations of the nearest towers in relation to where you shall be installing your antenna.

As a rule of thumb:

• If you are getting 3-4 bars signal strength outdoors and the tower(s) not too far away, then choose an omnidirectional.
• If you are getting 1-2 bars signal strength outdoors or the tower is further away, then choose a unidirectional. Please note that for best results a unidirectional requires a pretty clear line of sight towards the area that the tower is located.

If you would like any further advice then please do not hestitate to contact us.