Antenna sharing circuit, radio frequency circuit and mobile terminal

Abstract

The invention relates to an antenna sharing circuit, a radio frequency circuit and a mobile terminal. The antenna sharing circuit comprises an antenna matching circuit, a first filter, a radio frequency switch and a second filter. The antenna matching circuit is used for receiving radio frequency signals located at a first radio frequency band and radio frequency signals located at a second radio frequency band, matching impedance bandwidth of the first radio frequency band and expanding impedance bandwidth of an antenna, wherein the radio frequency signals located at the first radio frequency band and the radio frequency signals located at the second radio frequency band are transmitted by the antenna. The input end of the first filter is connected with the output end of the antenna matching circuit and used for restraining radio frequency signals located out of the first radio frequency band and transmitted by the antenna. The input end of the radio frequency switch is connected with the output end of the antenna matching circuit, the output end of the radio frequency switch is connected with the input end of the second filter, and the second filter is used for restraining radio frequency signals located out of the second radio frequency band and transmitted by the antenna. The antenna sharing circuit, the radio frequency circuit and the mobile terminal reduce China mobile multimedia broadcasting (CMMB) function lead-in cost and technical risks of terminal device manufacturers and solve an important technical bottleneck problem for terminal device CMMB function lead-in.

Description

technical field [0001] The invention relates to the communication field, in particular to an antenna sharing circuit, a radio frequency circuit and a mobile terminal. Background technique [0002] Since CMMB (China Mobile Multimedia Broadcasting, China Mobile Multimedia Broadcasting) digital TV started broadcasting, various mobile terminals have introduced CMMB functions one after another. The popularity of the CMMB function in mobile terminals is getting higher and higher, and it is also more and more accepted and loved by the majority of users. [0003] A mobile terminal with CMMB function, such as a mobile phone, needs to be equipped with a CMMB antenna in addition to a mobile communication antenna. For the CMMB antenna, the usual practice in the industry is to externally install the rod antenna or to build it in. Due to the wide CMMB frequency band, the theoretical design length of the rod antenna is required to be 140mm-160mm, which affects the appearance of the termi...

AI Technical Summary

Problems solved by technology

Due to the wide CMMB frequency band, the theoretical design length of the whip antenna is required to be 140mm-160mm, which affects the appearance of the terminal and is not conducive to user use.

Although the built-in CMMB antenna does not affect the appearance of the terminal, it needs to reserve a large space for the CMMB antenna inside the mobile terminal, which affects the small size and portability of the mobile terminal and becomes a technical bottleneck for the terminal to integrate CMMB functions.

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