A dual mode array antenna including a ground plane, a plurality of antenna elements, a tuning mechanism for tuning the array antenna to a resonant frequency, and a base defining a cavity having a depth that is less than half of a wavelength at an upper frequency of the array antenna is disclosed. Each of the plurality of antenna elements includes at least one spiral arm and each of the plurality of antenna elements is embedded in the cavity. The dual mode array antenna operates between the upper frequency and a lower frequency and may operate in one or more resonant frequencies.