Frequency Reconfigurable Stacked Patch Microstrip Antenna (FRSPMA) for LTE and WiMAX Applications

This paper presents the frequency reconfigurable antenna that can be applied either in LTE (2.6 GHz) or WiMAX (3.5 GHz) applications. This antenna is designed with a combination of an aperture coupled as the feeding technique and stacked patch technology or known as a Frequency Reconfigurable Stacked Patch Microstrip Antenna (FRSPMA). It consists of three substrates layers where all the layers are designed using RT-Rogers 5880 with 0.787 mm thickness. Air gap with 3 mm thickness is located between the ground and bottom patch substrate to enhance the gain performances and reducing the spurious effects from the feeding line. The designed was simulated using CST Microwave Studio at operating frequency of 1 GHz to 4 GHz. The effect of switch configuration either at ON or OFF state were studied. By configuring the RF switch at the feedline, the activation of the different radiating patch at different substrate layers (top or bottom patch) and aperture slots antenna can be controlled. During the ON state, both radiating patches and aperture slots are activated and operated at 2.6 GHz with -25.58 dB. While during the OFF state, only bottom patch and aperture slot 1 are activated and at this time the antenna can be operated at frequency 3.5 GHz with -45.37 dB. Good agreement between simulation and measurement results is achieved. The performance of the designed antenna was analyzed in term of return loss, VSWR, gain and radiation pattern.