Miniature Antennas with Low Proximity Effects and Filter Response Characteristics for Bluetooth and 3G Applications

摘要

Handset design teams are returning to the difficulties that are imposed by frequency division duplex architectures, once a feature of first generation analogue phones, and now brought into the spectrum of 3G services as defined by the IMT-2000 specifications. In the case of the broadband 3G embodiments the problem is exacerbated by the broad-bandwidth of the channel (～5MHz) so that it is important to defend the receiver channel in the terminal from noise and interference from the transmit channel, from other noise generators and other radios in the terminal. Receiver sensitivity is additionally impaired by the electrical noise that is developed by the high-density electronics payload that is necessary to provide the functionality that is expected of 3G terminals. Basically the higher processing demands that are imposed by fast data-throughputs, high resolution displays, location processing systems and perhaps Bluetooth modems all create new sources of noise in juxtaposition with a receiving channel with a wider channel to receive noise in. As new functionality is brought into the handset, new solutions to the receiver circuitry are required to mitigate interference.