The herein described technology provides a hybrid monopole and slot antenna assembly including an electrically-driven monopole antenna and a parasitic slot antenna. The electrically-driven monopole antenna is fed by a feed line coupled to a first metal portion of a device case exterior, and the parasitic slot antenna is capacitively-driven by a radiating feed element embedded in a dielectric material that resonates a second metal portion of the device case exterior. The hybrid monopole and slot antenna assembly further includes a dielectric gap insert electrically separating the first metal portion of the device case exterior from the second metal portion of the device case exterior, and a modem that drives the electrically-driven monopole antenna at a first frequency and the parasitic slot antenna at a second different frequency.