Electronic devices with lower antenna switching

An electronic device comprising:

• peripheral conductive housing structures having a first segment, a second segment separated from the first segment by a first dielectric-filled gap, and a third segment separated from the second segment by a second dielectric-filled gap;
• ground structures separated from the peripheral conductive housing structures by a slot;
• a first positive antenna feed terminal coupled to the first segment;
• a second positive antenna feed terminal coupled to the second segment;
• a first switch coupled between a first point on the second segment and the ground structures across the slot;
• and
• a second switch coupled between a second point on the second segment and the ground structures across the slot, the first point being interposed on the second segment between the second positive antenna feed terminal and the first dielectric-filled gap, and the second point being interposed on the second segment between the second positive antenna feed terminal and the second dielectric-filled gap, wherein
• the first switch and the second switch have a first tuning state in which the first switch is closed and the second switch is closed,
• the first switch and the second switch have a second tuning state in which the first switch is open and the second switch is open,
• the first switch and the second switch have a third tuning state in which the first switch is open and the second switch is closed, and
• the second segment forms a parasitic antenna resonating element for the first segment in a first frequency band while the first switch and the second switch are in the third tuning state.