Currently, to meet ever-increasing user requirements on download rates and multi-standard roaming of mobile terminals, an operator not only makes transition from 2G and 3G networks to a 4G LTE network, but also provides a mode of multi-network roaming and a mode of simultaneous voice and data processing, such as SVDO, SV-LTE, and SG-LTE. For example, China Mobile provides a mode of multiple communications standards and multiple frequency bands, where the multiple communications standards are the TD-LTE communications standard, the FDD-LTE communications standard, the GSM communications standard, the TD-SCDMA communications standard, and the WCDMA communications standard, and a quantity of supported frequency bands is from frequency band 10 to frequency band 13. For better user experience, China Mobile provides a concept of SG-LTE, in which voice and data services can be processed simultaneously, that is, voice is processed in a GSM network and data is processed in a TD-SCDMA or TD-LTE network simultaneously.
For the mode of simultaneous voice and data, at least two radio frequency circuits and at least two broadband multi-band primary antennas are needed. Generally, two broadband multi-band antennas both need to cover a low-frequency signal and a high-frequency signal, and the two broadband multi-band antennas have a requirement for a large space size, which can hardly be implemented for a mobile terminal that has an ever-decreasing size.
USPTO Backgrounds
USPTO Backgrounds