A Novel Tapped-Feeding Broadside Radiated Loop Antenna

We present a method for designing a novel broadside radiated loop antenna utilizing the tapped-feeding method. The tapped feeding along the magnetic wall of the loop is employed to perform impedance matching of the first mode in the loop antenna. It is interesting that due to the use of balanced feeding method, the antenna has a virtual ground, and the wide impedance matching segment generates a controllable half wavelength resonant structure at high frequency, thus expand the working frequency band of the antenna. Besides, the folded resonator makes the two halves of the resonator's radiation current in the same direction, thereby enhancing the gain. For experimental demonstration, we design and test the antenna. We show that the relative bandwidth of the antenna is 33%, covering 2 to 2.8 GHz, centered at 2.4 GHz, and the gain of the loop antenna in the working band is 5.3-6.8dBi.