A mobile device comprising: a decorative trim for an outer casing of the mobile device; and a multiband monopole antenna comprising: a radiator element formed from a first part of the decorative trim, the radiator element having a first end coupled to a feed point and a second end which is a radiator tip of the radiator element; a switch having a control line and being positioned to effectively electrically connect or disconnect the radiator tip from a second part of the decorative trim used as ground; an impedance matching portion formed from a third part of the decorative trim and having a first end coupled to the feed point and a second end coupled to ground; and a circuit element positioned along the impedance matching portion; the mobile device further comprising: a proximity sensor for detecting proximity to a user; and a modem coupled to the control line of the switch, to the circuit element, and to the proximity sensor, wherein the modem is configured to selectively open or close the switch and to be responsive to the proximity sensor for controlling the circuit element to adjust the impedance of the multiband monopole antenna. a decorative trim for an outer casing of the mobile device; and a multiband monopole antenna comprising: a radiator element formed from a first part of the decorative trim, the radiator element having a first end coupled to a feed point and a second end which is a radiator tip of the radiator element; a switch having a control line and being positioned to effectively electrically connect or disconnect the radiator tip from a second part of the decorative trim used as ground; an impedance matching portion formed from a third part of the decorative trim and having a first end coupled to the feed point and a second end coupled to ground; and a circuit element positioned along the impedance matching portion; a radiator element formed from a first part of the decorative trim, the radiator element having a first end coupled to a feed point and a second end which is a radiator tip of the radiator element; a switch having a control line and being positioned to effectively electrically connect or disconnect the radiator tip from a second part of the decorative trim used as ground; an impedance matching portion formed from a third part of the decorative trim and having a first end coupled to the feed point and a second end coupled to ground; and a circuit element positioned along the impedance matching portion; the mobile device further comprising: a proximity sensor for detecting proximity to a user; and a modem coupled to the control line of the switch, to the circuit element, and to the proximity sensor, wherein the modem is configured to selectively open or close the switch and to be responsive to the proximity sensor for controlling the circuit element to adjust the impedance of the multiband monopole antenna. a proximity sensor for detecting proximity to a user; and a modem coupled to the control line of the switch, to the circuit element, and to the proximity sensor, wherein the modem is configured to selectively open or close the switch and to be responsive to the proximity sensor for controlling the circuit element to adjust the impedance of the multiband monopole antenna.