A multi-sector antenna system is disclosed that includes two or more flat panel antennas facing different directions and configured to communicate with two separate sites using millimeter wave RF signals. A processing module is communicatively coupled to each of the flat panel antennas. In some embodiments, the processing module may be configured to receive incoming RF signals from a first site via a first flat panel antenna, convert the incoming RF signals to outgoing RF signals, and transmit the outgoing RF signals to a second site via the second flat panel antenna. The flat panel antennas may be configured to transmit and receive RF signals at frequencies in the range of about 57 GHz to 86 GHz. The multi-sector antenna system may be utilized in a mesh network system.