A portable wireless device operating within a specific bandwidth is provided. Conductor elements such as the circuit board, the battery, the card slot, the multimedia socket and the resonator are installed inside the housing of a portable wireless device. The body of the resonator is made of dielectric material with the positive electrode and the negative electrode being formed on the two lateral sides of the dielectric material. The positive electrode and the negative electrode have a positive polarity regulating piece and a negative polarity regulating piece respective with capacitance effect existing between the positive and the negative regulating pieces regulating both the impedance matching and the phase thereof. The resonator, when operating within the range of resonance frequency, is able to couple the energy to conductor elements and generate a radiation field for the portable wireless device together with the conductor elements.