Compatibility summary
You will need a travel adapter in Antigua and Barbuda; plug types used there differ from Brazil. Voltage differs by more than 20% — a voltage converter may be needed for some appliances.
Plug comparison
Brazil plug types: C N
Antigua and Barbuda plug types: A B
There is no common plug type between Brazil (C N) and Antigua and Barbuda (A B). You need a travel adapter.
Voltage comparison
Brazil: 127V, 60Hz
Antigua and Barbuda: 230V, 60Hz
Voltage converter recommended (Brazil 127V vs Antigua and Barbuda 230V).