An antenna device comprising: first and second communication circuit modules; a circuit board; radiators disposed on the circuit board, and configured to be provided by the first communication circuit module with a first feeding signal to transmit or receive a wireless signal in a first frequency band; a ground disposed on the circuit board to provide a reference potential for the radiators; and electric conductors provided in gaps between the radiators, respectively, wherein: the radiators and a whole or a portion of the ground are configured to be provided by the second communication circuit module with a second feeding signal to transmit or receive a wireless signal in a second frequency band that is lower than the first frequency band; and some of the radiators form an inductive or capacitive coupling with the ground, and when the second feeding signal is provided, the ground and some of the radiators, which form the inductive or capacitive coupling with the ground, transmit or receive a wireless signal in the second frequency band, wherein the electric conductors form an inductive or capacitive coupling with the ground, and wherein when the second feeding signal is provided, the ground and electric conductors (535, 555), which form the inductive or capacitive coupling with the ground, transmit or receive a wireless signal in the second frequency band, wherein the circuit board comprises layers and includes a plurality of via holes formed in each of the layers, and the electric conductors are formed by a combination of conductive materials filled in the via holes of different layers. first and second communication circuit modules; a circuit board; radiators disposed on the circuit board, and configured to be provided by the first communication circuit module with a first feeding signal to transmit or receive a wireless signal in a first frequency band; a ground disposed on the circuit board to provide a reference potential for the radiators; and electric conductors provided in gaps between the radiators, respectively, wherein: the radiators and a whole or a portion of the ground are configured to be provided by the second communication circuit module with a second feeding signal to transmit or receive a wireless signal in a second frequency band that is lower than the first frequency band; and some of the radiators form an inductive or capacitive coupling with the ground, and when the second feeding signal is provided, the ground and some of the radiators, which form the inductive or capacitive coupling with the ground, transmit or receive a wireless signal in the second frequency band, wherein the electric conductors form an inductive or capacitive coupling with the ground, and wherein when the second feeding signal is provided, the ground and electric conductors (535, 555), which form the inductive or capacitive coupling with the ground, transmit or receive a wireless signal in the second frequency band, wherein the circuit board comprises layers and includes a plurality of via holes formed in each of the layers, and the electric conductors are formed by a combination of conductive materials filled in the via holes of different layers. the radiators and a whole or a portion of the ground are configured to be provided by the second communication circuit module with a second feeding signal to transmit or receive a wireless signal in a second frequency band that is lower than the first frequency band; and some of the radiators form an inductive or capacitive coupling with the ground, and when the second feeding signal is provided, the ground and some of the radiators, which form the inductive or capacitive coupling with the ground, transmit or receive a wireless signal in the second frequency band, wherein the electric conductors form an inductive or capacitive coupling with the ground, and wherein when the second feeding signal is provided, the ground and electric conductors (535, 555), which form the inductive or capacitive coupling with the ground, transmit or receive a wireless signal in the second frequency band, wherein the circuit board comprises layers and includes a plurality of via holes formed in each of the layers, and the electric conductors are formed by a combination of conductive materials filled in the via holes of different layers.