Bandwidth Enhancement of Printed Monopole Element Quasi-Yagi antenna using a Parasitic Resonator

In this paper, a method to enhance the bandwidth (BW) of a monopole element quasi-Yagi antenna (PQYA) is presented. A closely spaced U-shaped resonator (U-SR) with unequal arms in the end-fire direction is used to generate a new resonance at the high frequency. The evolution of the broadband parasitic U-SR is described. The prototype of the designed antenna is fabricated and tested with the size of 86 mm × 76 mm. The measured results show that the achieved BW is 1.55-2.67 GHz (53.1%) for |S
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| < -10 dB, and the gain is 4.05 ± 0.1 dBi for 91% of the BW. Measured and simulated results are in good agreement, which validates the proposed antenna.