A Frequency Reconfigurable Stacked Patch Microstrip Antenna (FRSPMA) using PIN diode switch

This paper presents a novel of a Frequency Reconfigurable Stacked Patch Microstrip Antenna (FRSPMA) integrated with radio frequency (RF) switch. It consists of three substrate layers where all layers uses RT-Rogers 5880 with a thickness of h1=0.787 mm. A 0.3mm (h2) thick air gap is filled between the stacked radiating patch (layer 1 and layer 2) and the feedline substrate to enhance the gain performances, thus reducing the spurious effects from the feeding line. A new coupling method applied in an aperture coupled technique that controlled by the switching circuit is presented. In this design, two different shapes of aperture slots (I-shape and H-shape) were etched on the ground plane. The position of each aperture slot must be located at the centre with reference to the bottom and top patch position. A PIN diode switch was deployed at the feed network to control the length of feedline in order to achieve frequency reconfigurable. By configuring the PIN diode switch either to ON or OFF state, the particular aperture slots on the ground plane will be activated or turned ON, hence allowing waves to radiate to the selected radiating element at different substrate layers (top or bottom patch). The activation of the selected aperture slots and radiating elements ensures the FRSPMA is capable to operate either at 2.6 GHz or 3.5 GHz frequency. The proposed antenna was then fabricated into two structures, with and without the real PIN diode switch (copper stripline). The simulated results were then compared with the measured results to ensure that the antenna's performance in terms of frequency, return loss, gain and the characteristics of the radiation pattern are exceptional. After observation and analyzing made, both results demonstrated a good impedance matching. The findings and results from this research grants a potential benefit to the comprehension of wireless communication systems, especially for Long Term Evolution (LTE) and WiMAX applications.