Miniaturized Four-Arm Log-Periodic Toothed Antenna With Wide Bandwidth

An improved method of wideband performance is demonstrated by being applied to a miniaturized four-arm log-periodic toothed antenna with an integrated balun. The required minimum length of the integrated balun is reduced through the input impedance reduction structure on thin dielectrics with a low relative dielectric constant. In addition, destructive currents arising from the combination of the antenna structure and miniaturization structure are solved by modeling them as an equivalent circuit structure from an impedance perspective. The proposed antenna represents a voltage standing wave ratio of less than 2:1 in the 1.25–18 GHz bandwidth range and has a realization gain of more than 2 dBi in the overall operating band with a diameter of 0.325 $\mathbf{\lambda}_{\mathbf {L}}$.