Antenna system with antenna swapping and antenna tuning

An electronic device, comprising:

• a housing having an upper end and a lower end;
• a peripheral conductive member that runs around the housing;
• an upper cellular telephone antenna that is formed at least partly from the peripheral conductive member and that is located at the upper end of the housing;
• a lower cellular telephone antenna that is formed at least partly from the peripheral conductive member and that is located at the lower end of the housing;
• radio-frequency transceiver circuitry including a transmitter and first and second receivers;
• switching circuitry that has first, second, third, and fourth ports, wherein:
• the first port receives signals from the transmitter and provides signals to the first receiver;
• the third port provides signals to the second receiver;
• the second port is coupled to the lower cellular telephone antenna;
• the fourth port is coupled to the upper cellular telephone antenna;
• the switching circuitry is operable in a first state in which the first port is connected to the second port and the third port is connected to the fourth port and is operable in a second state in which the first port is connected to the fourth port and the third port is connected to the second port;
• and
• when the switching circuitry is in the first state, the upper cellular telephone antenna receives signals in some cellular telephone communications band but does not transmit any signals;
• a fixed matching circuit coupled between the second port and the lower cellular telephone antenna;
• and
• an adjustable matching circuit coupled between the fourth port and the upper cellular telephone antenna, wherein the upper cellular telephone antenna comprises an inverted-F antenna, the peripheral conductive member runs across at least four exterior surfaces of the electronic device, the peripheral conductive member comprises dielectric-filled gaps that separate the peripheral conductive member into at least one segment, the inverted-F antenna has first and second branches that are formed from the segment and that are associated with respective first and second communications band antenna resonances, the electronic device has a length, a width perpendicular to the length, and a height perpendicular to the width and the length, the width is less than the length and the height is less than the width, and the at least two dielectric-filled gaps extend across the height of the electronic device from a rear face of the electronic device to a front face of the electronic device.

An electronic device, comprising:

• a housing having opposing first and second ends and four edges;
• a display mounted within the housing;
• a peripheral conductive member that runs along the four edges of the housing;
• an antenna ground that is formed at least partly from conductive portions of the housing;
• a first antenna that is formed from at least a first segment of the peripheral conductive member and the antenna ground;
• a second antenna that is formed from at least a second segment of the peripheral conductive member and the antenna ground;
• a third antenna that is formed within the peripheral conductive member;
• first radio-frequency transceiver circuitry having a transmit-receive port and a receive-only port;
• switching circuitry that is operable in a first mode in which the first antenna is coupled to the transmit-receive port and the second antenna is coupled to the receive-only port and that is operable in a second mode in which the first antenna is coupled to the receive-only port and the second antenna is coupled to the transmit-receive port, wherein the second antenna is connected only to a receiver in the radio-frequency transceiver circuitry that receives signals in some cellular telephone communications band when the switching circuitry is in the first mode;
• and
• second radio-frequency transceiver circuitry having a transmit-receiver port that is coupled to the third antenna without the switching circuitry, wherein the electronic device has a length, a width perpendicular to the length, and a height perpendicular to the width and the length, the width is less than the length and the height is less than the width, the antenna ground comprises a midplate member that extends across the width of the electronic device, wherein the midplate member is separated from the first segment of the peripheral conductive member by a dielectric opening so that the first segment and the midplate member surround the first dielectric opening.