Design and Analysis of a Compact Dual-Band Serpentine-Shaped Patch Antenna with Folded Stub Lines for C- and X-Band Applications

Abstract

Abstract—Antenna miniaturization plays an important role in modern wireless communication and has got some serious limitations. Gain and bandwidth degradations are two vital limitations in miniaturized antennas. Another problem faced by small antennas is efficiency degradation. This paper presents a compact dual-band serpentine-shaped antenna with folded stub lines having a total volume of 10 × 13 × 1.524 mm3 and mounted on the partial ground plane with the dimensions of 10 × 6.5 × 0.035 mm3. A size reduction of 82% (including ground plane) is achieved compared to the conventional square patch antenna working at 6.8 GHz. The proposed antenna is linearly polarized. The antenna is fed with a 50-ohm microstrip line. The radiating element of the proposed antenna is connected to quarter-wavelength folded stub lines. The measured by –10 dB level impedance bandwidths of the proposed antenna are 660.6 MHz (6.6–7.26 GHz) and 1.52 GHz (8.84–10.36 GHz) which covers C- band (4–8 GHz) and X-band (8 ~ 12 GHz) applications. Measured gains of 3.2, 5.41 and 5.56 dBi along with the measured efficiencies of 82.1, 86.3, and 88.1% are obtained at 6.8, 9.51, and 9.89 GHz respectively. The radiation patterns of the proposed antenna are found to be unidirectional in all the planes at 6.8 GHz, uni-directional in E-plane and omni-directional in H-plane at 9.51 GHz and uni-directional in all the planes at 9.89 GHz. All the measured and simulated results are in good agreement.