Page 31 - rise 2017

Body-centric wireless networks becomes of multiple wireless sensors that are placed on the
human/phantom body. The application of wireless sensor in on body communication for connecting
to body which provides the high data rates from low capacity, be small and lightweight in using of
high frequencies, and consume minimum power, which implies highly efficient links [5][6].

Designing Rectangular Patch Antenna in Free Space
The rectangular patch is by far the most widely used configuration. It is easy to analyze using both the
transmission-line and cavity models, which are most accurate for these substrates.

Figure 1: Layout of the rectangular patch antenna

For the principle E-plane (xy-plane), this is demonstrated in Figure 1 where the dimensions of the
patch along its length have been extended on each end by a distance ∆L, which is function of the
effective dielectric constant eff and the width-to-height ratio (w/h). Due to fringing, electrically the
size of the antenna is increased by an amount of (ΔL). Therefore, the actual increase in length (ΔL) of
the patch is to be calculated using the following equation [14], [1];

(1)

Where h is height of the substrate. For practical length (L) of the patch is calculated using the
below mentioned equation [14], [1];

L  C0  2  L (2)
2 fr  reff

A practical width that leads to good radiation efficiencies is calculated by [14], [1];

C 0 2 (3)
w 
2 rf r   1

Where W is a practical width of the patch, C 0 is a speed of light and ε r is the dielectric
substrate. The length and width of a substrate is equal to that of the ground plane. The length of a
ground plane (L g) and the width of a ground plane (W g) are calculated using the following equations
[1];
L g = 6h + L (4)
W g = 6h + W (5)

The type of feeding technique that will be used is the inset feed technique. It is one of the
easiest feeding techniques and it is also easy to control the input impedance of the antenna.