An apparatus includes a radio frequency (RF) circuit to transmit or receive RF signals. The apparatus further includes a loop antenna to transmit or receive the RF signals. The apparatus further includes an impedance matching circuit coupled to the RF circuit and to the loop antenna. The impedance matching circuit includes lumped reactive components.

An apparatus includes a radio frequency (RF) circuit to transmit or receive RF signals. The apparatus further includes a loop antenna to transmit or receive the RF signals. The apparatus further includes an impedance matching circuit coupled to the RF circuit and to the loop antenna. The impedance matching circuit includes lumped reactive components.

An apparatus includes a radio frequency (RF) circuit to transmit or receive RF signals. The apparatus further includes a loop antenna to transmit or receive the RF signals. The apparatus further includes an impedance matching circuit coupled to the RF circuit and to the loop antenna. The impedance matching circuit includes lumped reactive components.

An apparatus includes a radio frequency (RF) circuit to transmit or receive RF signals. The apparatus further includes a loop antenna to transmit or receive the RF signals. The apparatus further includes an impedance matching circuit coupled to the RF circuit and to the loop antenna. The impedance matching circuit includes lumped reactive components.

The antenna device A1 includes an antenna 1 configured to transmit and/or receive radio waves, and a dielectric elastomer drive element 2 including a dielectric elastomer layer 21 and a pair of electrode layers 22 sandwiching the dielectric elastomer layer 21. The dielectric elastomer drive element is capable of changing an antenna characteristic of the antenna 1. With such a configuration, the antenna device can be made smaller and lighter while improving its antenna characteristics.

The antenna device A1 includes an antenna 1 configured to transmit and/or receive radio waves, and a dielectric elastomer drive element 2 including a dielectric elastomer layer 21 and a pair of electrode layers 22 sandwiching the dielectric elastomer layer 21. The dielectric elastomer drive element is capable of changing an antenna characteristic of the antenna 1. With such a configuration, the antenna device can be made smaller and lighter while improving its antenna characteristics.

An apparatus includes a radio frequency (RF) circuit to transmit or receive RF signals. The apparatus further includes a loop antenna to transmit or receive the RF signals. The apparatus further includes an impedance matching circuit coupled to the RF circuit and to the loop antenna. The impedance matching circuit includes lumped reactive components.

An apparatus includes a radio frequency (RF) circuit to transmit or receive RF signals. The apparatus further includes a loop antenna to transmit or receive the RF signals. The apparatus further includes an impedance matching circuit coupled to the RF circuit and to the loop antenna. The impedance matching circuit includes lumped reactive components.

An apparatus includes a radio frequency (RF) circuit to transmit or receive RF signals. The apparatus further includes a loop antenna to transmit or receive the RF signals. The apparatus further includes an impedance matching circuit coupled to the RF circuit and to the loop antenna. The impedance matching circuit includes lumped reactive components.

An apparatus includes a radio frequency (RF) circuit to transmit or receive RF signals. The apparatus further includes a loop antenna to transmit or receive the RF signals. The apparatus further includes an impedance matching circuit coupled to the RF circuit and to the loop antenna. The impedance matching circuit includes lumped reactive components.