RESUMO
This paper proposes a compact double-layer microstrip patch antenna with a wide bandwidth of 4.83-6.1 GHz and a gain reaching 4.7 dBi. By folding its mirror image through the electric field symmetry principle of the microstrip antenna, its electrical properties are maintained, and the physical size is halved to the compact size of only 25 × 40 mm2. The proposed antenna has the radiation characteristics of a planar inverted-F antenna (PIFA), which can generate the first resonant frequency and realize omnidirectional radiation characteristics. By coupling and feeding the upper patch, the second resonant frequency of the proposed antenna is produced and the directional radiation characteristics of the microstrip patch antenna can be achieved. The consistency of the results between the simulation and test indicates that the proposed antenna design is an ideal potential choice for home wireless local area network (WLAN) communication.
RESUMO
A novel compact tapered-slot-fed antenna (TSA) with anti-spiral shape and lumped resistors is presented for ultra-wideband (UWB) applications. Unique coplanar waveguide (CPW) to coplanar strip (CPS) feeding structure and exponential slot are designed to ensure the continuous current propagation and good impedance matching. With a pair of anti-spiral-shaped structure loadings at the end of the antenna, the radiation performance in lower operating band can be enhanced obviously. The typical resistor loading technique is applied to improve the time domain characteristics and expand the bandwidth. The fabricated prototype of this proposed antenna with a size of 53 × 63.5 mm2 was measured to confirm simulated results. The proposed antenna has S11 less than -10 dB in the range of 1.2-9.8 GHz, and the group delay result is only 0.4 ns. These findings indicate the proposed antenna can be taken as a promising candidate in UWB communication field.
