High-Q antennas with built-in coils: For mobile devices

Efficiency and isolation, at low frequencies (700 MHz), are two of the most important metrics for successful multi-communication implementation. This paper presents an antenna concept, that exhibits a very high isolation between high-Q Tx and Rx antennas at 700 MHz. Furthermore, it is shown how coils can be integrating into the antenna structure for obtaining better efficiency. It is shown that by integrated coils into the antenna structure, the efficiency can be improved by 2dB for each antenna.