Design of 2.4 GHz/5 GHz planar dual-band electrically small slot antenna based on impedance matching circuit

A dual-band electrically small antenna based on impedance matching circuit is proposed. Which is fed by coplanar waveguide (CPW). The antenna includes two twin-spiral type slot-line short stubs and three open-circuited series-stubs with slot-line loaded at the central feed line of the CPW as impedance matching network. The total size of the antenna is 12.45mm×13.05mm×0.8mm , with Kα=0.45 and 0.95 at 2.4 GHz and 5 GHz respectively. By the introduction of the proposed impedance matching network, the syntonic frequency of the antenna is achieved at 2.4 GHz and 5 GHz. And the measured bandwidth of S11<-10dB is about 7.5% and 12% of the two resonant frequencies. The proposed antenna has a very small ground plane (0.9mm×1.8mm). And it is appropriately applied to wireless communication for considerable radiation efficiency.