# 3

3.1 0th Iteration

The 0th iteration mainly consists of the basic patch with dimensions 11.33×11.33mm. The feed position is taken at 1.9mm from the x-axisas shown in the g.3.1 The R.L vs. frequency graph is shown in g.3.2. The g.3.3 shown below represents VSWR graph. The Smith Chart for change in Width is as shown in g.3.4.

We Will Write a Custom Essay Specifically
For You For Only \$13.90/page!

order now

10

Figure 3.1: 0th Iteration

Figure 3.2: R.L Vs Frequency Graph

Figure 3.3: VSWR Graph

Figure 3.4: Smith Chart

3.2 1st Iteration

The 1th iteration includes removing the slots having centre at 4.265mm from the axis and slot width of 2.6mm to increase the bandwidth of the antenna. In rst Iteration,the feed is given at a distance of 1.65mm from the centre.This is because the feed should be such that, the smith chart should passes from the centre, so that the impedance is 50 which is matched with probe feed connector leading to high power transfer.VSWR graph gives information about the frequency resonance and bandwidth. The R.L vs frequency graph is shown in g.3.6. The g.3.7 shown below represents VSWR graph. The Smith Chart for change in Width is as shown in g 3.8.

Figure 3.5: 1st Iteration

Figure 3.6: R.L Vs Frequency Graph

Figure 3.7: VSWR Graph

Figure 3.8: Smith Chart

Chapter 4

Optimized Structure

The proposed antenna is designed by using concept of Minkowski fractal structure, which originates from the plane square patch and subsequent fractal antenna. Minkowski iterations produce a cross-like fractal patch with even more ne details at the edges. The antenna is designed by using the square patch and iterating rst iteration at the center of each side. Iterated polygons (indentation) in the shape of square are created. The square patch fractal antenna is based on minkowski square shape with a ground dimension of 38mX38mm and patch dimension of 11.33mmX11.33mm . The FR-4 material is used as substrate. The thickness of the substrate is 1.59 mm. The dielectric constant (r) of the antenna is 4.4.To design the fractal antenna a square shape structure is designed on the simulator.Square indentation is cut down from the each side of the square, by doing this the path for the current ow also increases and the e ciency of the antenna also increases.

14

Figure 4.1: R.L Vs Frequency Graph

Figure 4.2: VSWR

Figure 4.3: Smith Chart

Figure 4.4: Gain Vs Frequency