Broadband and high gain low profile(thin) capacitive-coupled microstrip antennas for wireless applications

Broadband antennas that are small in size and simple in structure are typically demanded for such applications. In this paper, we present two prototypes of microstripline fed capacitively coupled microstrip antennas. First prototype consists of microstripline fed capacitively coupled for broadband antenna at 2.5 GHz. This bandwidth is 11 times greater than conventional microstrip antenna (MSA). Here, air-gap (Δ) of 7 mm is used between the ground plane and the substrate. The second prototype antenna is a high gain low profile gap-coupled microstrip antenna consisting of a slot in the radiating patch. The location of the slot is placed in an appropriate location in order to get high gain. Using radiating slot in the patch gain has been enhanced significantly over convention antenna. The obtain gain is 9.73 dB.