Shared antenna structures for near-field communications and non-near-field communications circuitry

Antenna structures in an electronic device having a length, a width, and a height, the antenna structures comprising:

• an inverted-F antenna resonating element formed from metal structures, wherein the metal structures extend across the width and the height of the electronic device;
• an antenna ground that is separated from the metal structures by an opening;
• an antenna feed path that is coupled to the inverted-F antenna resonating element, wherein the inverted-F antenna resonating element and antenna ground are configured to exhibit an antenna resonance in a communications band above 700 MHz and at least part of the metal structures form a near field communications loop antenna that is configured to transmit near field communications signals in a near field communications band;
• a first path coupled between the inverted-F antenna resonating element and the antenna ground across the opening;
• and
• a second path coupled between the inverted-F antenna resonating element and the antenna ground across the opening, wherein the first path forms a short circuit across the opening that forms a portion of the near field communications loop antenna and the second path forms an open circuit in the near field communications band, and the second path forms a short circuit across the opening that forms a return path for the inverted-F antenna resonating element and the first path forms an open circuit in the communications band above 700 MHz.