A miniaturized independently tuning dual-band multi-mode antenna using the postwall slotline

A miniaturized independently tuning dual-band multi-mode antenna using postwall slotline (PWS) is proposed and simulated in this work. The antenna consists a stepped impedance slot and a patch on the other side of the substrate, and the patch is attached at the edge of the slot by shorting pins. The stepped impedance slot based on the postwall slotline is actually a dual-mode slotline antenna working at 2.81 GHz-3.19 GHz, as a low frequency operating band, and the patch works at a higher frequency band of 4.43 GHz-4.56 GHz. The use of stepped impedance slot miniaturizes the size and widens bandwidth of the antenna. Both the slot and the patch are fed by a microstrip line, and their operating band can be controlled independently, which is a good merit for applications of wireless communication.