Miniaturized broadband printed unidirectional antenna with parasitic slots for indoor wireless applications

In nowadays communication systems, the size and performance of antennas are simultaneously required, since there is a tremendous demand for an ultra-wideband, compact and efficient antenna structures that may perform at all desired sub-bands starting from LTE (780MHz) up to WiMAX applications (5.5 GHz) with a good level of radiation efficiency and dimensions not exceeding 130mm*100mm*10mm. All these features are hard to achieve simultaneously. Therefore, for the sake of satisfying these demands, it has been suggested in this study to add parasitic slots to the printed Quasi-Yagi antenna, where by modifying their shapes, sizes and positions within the antenna, a significant performance is obviously detected. Simulation results using CST software suite have shown a clear enhancement in the bandwidth (6:1), and radiation efficiency (Gain = 5dB on average) with a very compact antenna structure allowing it to compete with the well-known antenna systems provided by international antenna companies like KATHREIN and TAOGLASS etc. Results are based on CST simulations and practical measurements.