A Reconfigurable Stacked Patch Microstrip Array Antenna (RSPMAA) for Long Term Evolution (LTE) and WiMAX applications

This paper presents a novel of a Reconfigurable Stacked Patch Microstrip Array Antenna (RSPMAA) integrated with radio frequency (RF) switches at the feedline. The antenna uses a combination of aperture coupled technique and stacked patch technology for reducing spurious radiation patterns. Generally, this RSPMAA consist of three substrate layers (RT-Rogers 5880) and an air filled substrate between stacked patches and the ground plane. The top patches is a rectangular shaped with an H-shaped hole at the centre and the bottom patches is a H-shaped, both etched on top of substrate 1 and substrate 2 respectively to play role as a radiating element. Four sets of aperture slots for each short and long on the ground are positioned at the centre with reference to the top patches and bottom patches. A new concept of coupling methods is implemented in aperture coupled technique where four RF switches are employed at the feed network to achieve the frequency reconfigurable. By configuring all the RF switches to ON or OFF state, the length of the feedline network will be changed and activates the particular aperture slots on the ground. The activation of the selected aperture slots will produce waves and radiates the signal to the particular radiating layers of the patch antenna. Two different frequencies, either at 2.6 GHz or 3.5 GHz were achieved through the RSPMAA when all the RF switches are in ON or OFF state respectively. Observed from the results, it is demonstrated the good results between simulation and measurement with good impedance matching. However it clearly shows that the measured results are much better than to the simulated results and as close as to ideal case usage. This RSPMAA has a great potential for Long Term evolution (LTE) and WiMAX applications.