A Simple Design of Multi Band Microstrip Patch Antennas Robust to Fabrication Tol- Erances for Gsm, Umts, Lte, and Bluetooth Applications by Using Genetic Algorithm Op- Timization

Design of multiband antennas with low volume is of practical interest for the ever growing wireless communication industry. In this regard, the design of a small multi band microstrip patch antenna (MPA) for GSM900 (880–960 MHz), GSM1800 (1710–1880MHz), GSM1900 (1850–1990 MHz), UMTS (1920–2170MHz), LTE2300 (2305–2400MHz), and Bluetooth (2400– 2483.5MHz) applications by using a genetic algorithm (GA) is proposed. The proposed GA method divides the overall patch area into different cells taking into account that cells have a small overlap area between them. This avoids optimized geometries with certain cells having only an infinitesimal connection to the rest of the patch. Therefore, the proposed method is robust for manufacturing. A shorting pin is also included for impedance matching. GA optimization combined with finite element method (FEM) is used to optimize the patch geometry, the feeding position and the shorting position. A prototype has been built showing good agreement with the simulated results. The optimized MPA has a footprint of 46 mm × 57mm Received 27 October 2012, Accepted 26 November 2012, Scheduled 7 December 2012 * Corresponding author: Jeevani Windhya Jayasinghe ([email protected]). 256 Jayasinghe, Anguera, and Uduwawala (0.138λ × 0.171λ at 900MHz) and an air gap of 10mm. It shows a reflection coefficient less than −10 dB at all six bands and can be useful for a base station antenna.