Antenna module,mobile terminal and method for tuning the antenna module

An antenna module for a mobile terminal, the mobile terminal comprising a metal frame and a system grounding spaced apart from the metal frame, where in

• the antenna module comprises a radiating body formed in the metal frame and a parasitic element coupled to the radiating body, the radiating body is configured for generating a main harmonic, and the parasitic element is configured for generating a parasitic harmonic;
• the antenna module further comprises a first tuning circuit and a second tuning circuit, wherein, the first tuning circuit is connected in series between the radiating body and the system grounding, the second tuning circuit is connected in series between the parasitic element and the system grounding;
• where in, the antenna module comprises at least four operation modes, wherein
• in a first operation mode, the first tuning circuit switches among multiple operation states such that the main harmonic covers an LTE low frequency and switches among multiple wave bands of the LTE low frequency, the second tuning circuit is configured to keep one operation state such that the parasitic harmonic covers an LTE medium frequency and an LTE high frequency, the second tuning circuit comprises one small-capacitance capacitor, a capacitance of the small-capacitance capacitor is less than 0.8 pF;
• in a second operation mode, the first tuning circuit switches among multiple operation states such that the main harmonic covers the LTE low frequency and switches among multiple wave bands of the LTE low frequency, the second tuning circuit switches among multiple operation states such that the parasitic harmonic covers the LTE medium frequency and switches among multiple wave bands of the LTE medium frequency;
• in a third operation mode, the first tuning circuit switches among multiple operation states such that the main harmonic covers the LTE low frequency and switches among multiple wave bands of the LTE low frequency, the second tuning circuit switches among multiple operation states such that the parasitic harmonic covers the LTE high frequency and switches among multiple wave bands of the LTE high frequency;
• in a fourth operation mode, the first tuning circuit is configured to keep one operation state such that the main harmonic covers the LTE medium and high frequencies, the second tuning circuit is configured to keep one operation state such that the parasitic harmonic covers the LTE medium and high frequencies.