Built-in FM antenna realization method and mobile phone using same

Abstract

The invention discloses a built-in frequency modulation (FM) antenna realization method and a mobile phone using the same. The mobile phone comprises a mobile phone shell and a mobile phone main board in the mobile phone shell, wherein the mobile phone main board is provided with an FM chip and an antenna matching circuit; the mobile phone shell is provided with an annular first antenna body and an annular second antenna body; and the first antenna body is arranged on the periphery of the second antenna and is connected with the antenna matching circuit through a transmission line. Due to the adoption of an inductive coupling feed structure, the second antenna body feeds and excites the first antenna body on the periphery of the second antenna body to radiate energy; because of the interaction of the two annular antennas, the input impedance of an electric small ring approaches the characteristic impedance of a feeder, the matching difficulty of an FM antenna and a feeder is lowered, the structure of the built-in FM antenna is simplified, and the impedance bandwidth of the antennae is increased; and under the same environmental conditions, the performance of the FM antennae is improved, and the needs for the FM transmission function are satisfied.

Description

technical field [0001] The invention relates to the field of mobile phones with FM radio functions. More specifically, the improvement relates to a method for realizing a built-in FM antenna and the mobile phone. Background technique [0002] As the size of mobile phones decreases, more and more attention is paid to antenna devices used to transmit / receive radio waves to transmit / exchange radio data, for example, FM (Frequency Modulation, frequency modulation) antennas for FM radio functions on mobile phones. Due to its own low operating frequency, the FM antenna has a relatively large size and is often difficult to integrate inside the mobile phone. Usually, the ground wire of the earphone part is used as the FM antenna. [0003] In recent years, the design of built-in FM antennas has gradually attracted attention, and some built-in FM antennas have also appeared, for example, ceramic antennas. It utilizes ceramic materials with high dielectric constant to reduce the opera...

AI Technical Summary

Problems solved by technology

[0004] However, the ceramic material with high dielectric constant also reduces the working bandwidth of the antenna. Moreover, the ceramic antenna usually has a rectangular parallelepiped shape, which is difficult to meet the design needs of mobile phones with changing shapes.

[0005] There is also an electrically tuned antenna in the prior art, which adjusts the resonant frequency point of the antenna through an automatic matching circuit, which requires the cooperation of software and hardware at the same time during operation, the design is relatively complicated, and the production cost is relatively high.

[0006] Therefore, prior art still needs to improve and develop

Images