Design of a Microstrip-fed printed-slot antenna using defected ground structures for Multiband applications

Abstract

This paper presents the design of a microstrip-fed, planar-printed, slot antenna using defected ground structures (DGSs) for multiband applications. The antenna structure consists of two groups of five straight slot elements. The slot elements in each group are of the same width but different lengths on the ground plane and separated by a small strip and a slot cut on both sides of the strip to interconnect the group of slots with each other. The microstrip line is designed on the front side of the PCB with a right angle for all the slots to make it easy to mount the slots and the microstrip with a monolithic microwave integrated circuit (MMIC). The proposed antenna is designed and simulated using an electromagnetic simulator based on the method of moment (MoM). For the validation the antenna was fabricated on a double-sided substrate material that was 0.79 mm thick with an area of 45 × 40 mm2. The simulation and measurement results show that the antenna has good input-impedance bandwidths of S11 ≤-10 dB at the five operating frequencies of 3.5, 4.1, 5, 6.4, and 6.8 GHz and that extends in the range 2 to 7.5 GHz. The measurements were found to be in good agreement with the simulation results for S11 and provide a stable radiation pattern.