### I. Introduction

### II. Antenna Geometry

_{L}) of 21 mm and width (F

_{W}) of 3.06 mm. The geometry of the proposed antenna is shown in Fig. 1. The snapshot of the proposed antenna is shown in Fig. 2. The antenna occupies a small volume of 38×20×1.6 mm

^{3}only.

_{1}and P

_{2}of the patch, as shown in Fig. 1(a). The reference coordinate position is indicated as P

_{0}(0, 0, 1.6), and the coordinate positions of the two circular patches are P

_{1}(23, −5, 1.6) and P

_{2}(24, 4, 1.6), as depicted in Fig. 1(a). Next, a patch (circular) of a radius 3.6 mm is added in the middle position to complete the radiating patch. A vase-shaped ground plane is shown in Fig. 1(b), which consists of a rectangular ground plane of length = 16 mm and width = 20 mm. An elliptical ground is added to the rectangular ground plane. The elliptical ground portion has dimensions of L

_{2}= 15.38 mm and W

_{2}= 7 mm; it is placed at the coordinate position of P

_{3}(15.5, 5, 0) as shown in Fig. 1(b). The top and bottom views of the fabricated antenna are shown in Fig. 2.

### III. Design Procedure

_{1}and width W

_{1}is made on the initial circular patch, resulting in Antenna A. Furthermore, two circular slits of radius R

_{2}are made on Antenna A, generating Antenna B. Next, a circular patch of radius R

_{3}is inserted on the top edge of the semicircular patch, along with two circular patches of radius R

_{4}at positions P

_{1}and P

_{2}, resulting in Antenna C. Finally, an elliptical patch with a major axis of 3 mm and ratio of 2.5 is added on the top edge of the partial ground plane of Antenna C, generating the proposed antenna design (Antenna D).

### IV. Parametric Study

_{1}), where R

_{1}is varies from 7 mm to 10 mm with an increment of 1 mm. The

*S*

_{11}and gain versus frequency responses corresponding to the variation of R

_{1}are given in Fig. 5. From the

*S*

_{11}versus frequency plot, the impedance bandwidth of the antenna increases with an increase of R1. However, from the gain versus frequency plot, the antenna gain decreases as R

_{1}increases. Considering both the impedance bandwidth and gain, R

_{1}= 9 mm is considered the optimal value to implement the proposed antenna.

_{1}) made on the initial circular patch varies from 3 mm to 8 mm, with an increment of 1 mm. The

*S*

_{11}and gain versus frequency response corresponding to the variation of W

_{1}is shown in Fig. 6. From the

*S*

_{11}versus frequency plot, the impedance bandwidth of the antenna increases with an increase of W

_{1}. However, from the gain versus frequency plot, the antenna gain decreases as W

_{1}increases. Considering both impedance bandwidths and gain, W

_{1}= 6 mm is considered the optimal value to implement the proposed antenna.

_{2}) of Antenna B varies from 1 mm to 5 mm, with an increment of 1 mm. The

*S*

_{11}and gain versus frequency responses corresponding to the variation of R

_{2}are shown in Fig. 7. From the

*S*

_{11}versus frequency plot, the impedance bandwidth of the antenna increases with an increase in R

_{2}. However, from the gain versus frequency plot, the antenna gain decreases as R

_{2}increases. Considering both the impedance bandwidth and gain, R

_{2}= 3 mm is considered the optimal value to implement the proposed antenna.

_{3}) of the circular patch inserted on the top edge of the semicircular patch and radius (R

_{4}) of the two circular patches at positions P

_{1}and P

_{2}of Antenna C is studied simultaneously. R

_{3}varies from 1.6 mm to 3.6 mm, and R

_{4}varies from 2 mm to 4 mm, both with an increment of 1 mm, respectively. The

*S*

_{11}and gain versus frequency responses corresponding to the variation of R

_{3}and R

_{4}are shown in Fig. 8. From the

*S*

_{11}and gain versus frequency plots, both the impedance bandwidth and gain of the antenna increase with an increase in R

_{3}and R

_{4}. Considering both the impedance bandwidth and gain, R

_{3}= 3.6 mm and R

_{4}= 4 mm are considered the optimal values to implement the proposed antenna.

_{L}) is also studied. G

_{L}varies from 14 mm to 17 mm, with an increment of 1 mm. The

*S*

_{11}and gain versus frequency responses corresponding to the variation of G

_{L}are shown in Fig. 9. From the

*S*

_{11}and gain versus frequency plots, both the impedance bandwidth and gain of the antenna increase with an increase in G

_{L}. Considering both the impedance bandwidth and gain, G

_{L}= 16 mm is considered the optimal value to implement the proposed antenna.

*S*

_{11}and gain versus frequency responses corresponding to the variation of different dimensions of the elliptical patch are shown in Fig. 10. From the

*S*

_{11}and gain versus frequency plots, both the impedance bandwidth and gain of the antenna increase with an increase in the different dimensions of the elliptical patch. Considering both the impedance bandwidth and gain, major axis of 3 mm and ratio of 2.5 are considered the optimal values of the elliptical patch for implementing the proposed antenna.

### V. Results and Discussion

*S*

_{11}parameter is examined using the R&S ZNB20 vector network analyzer (Rohde & Schwarz, Munich, Germany). The 9.4 GHz (3.6–13 GHz) bandwidth is obtained by simulating the proposed antenna using the HFSS software simulation tool, which provides a simulated resonant frequency of 6.5 GHz and percentage bandwidth of 144.62%.

### VI. Performance Comparison

_{0}is the free-space wavelength at the lower edge measured frequency of 3.8 GHz. In the proposed design, the main objective has been to design a broadband antenna with high gain, which makes the proposed design highly suitable for broadband applications.