Capacitive Coupling Element Antennas for Multi-Standard Mobile Handsets

Antenna prototypes based on a simple capacitive coupling element (CCE) on a compact smartphone chassis are presented. This versatile antenna structure is easily modifiable with circuit design. We show with experimental data how the same CCE is implemented first with single-feed and then with dual-feed interface towards the transceiver front-end. These two antennas operate at the LTE-A frequencies 698-960 MHz and 1710-2690 MHz with good efficiency, owing to a novel dual-branch impedance matching circuit which utilizes the properties of the CCE and the chassis in a proficient way. A third antenna based on the same CCE is designed for a software defined radio receiver. This tunable antenna operates at 750-2500 MHz with acceptable efficiency.