Introduction on patch antenna

Antenna is the electrical conductor / system of the conductor, for a transmitter which radiate the electromagnetic energy into the space, and the Receiver, which collects the electromagnetic energy form the space [1]. The Microstrip antenna is developed for the determination of the moisture content for the heave rubber latex.  Microstrip antenna is the crucial variety of different applications of receivers as well as transmitter in the modern wireless society. Electromagnetic waves radiations form a microstrip patch antenna is due to fringing of field from a top patch in the form of substrate as present in the below figure. Microstrip patch sensor performance will affected through the permittivity of substrate as well as dimensions of the patch. [2]

Figure 1: Electromagnetic Wave fringe  

Literature Review on patch antenna  

According to the author Singh he has discussed about the Micro strip patch antenna and its various applications. This technology has gained a lot of attention in the last few years due to increase in technology. These antennas are compared with different antennas so these micro strip antennas have greater advantages like in performance, weight, size and cost. The best advantage is that these antennas can be fabricated easily on PCB. In this paper some disadvantages of these antennas are discussed and there are also some solutions that are used to overcome these issues (Singh & Tripathi, 2011).

In this paper author Llatser gives idea about the nano patch antenna for the terahertz radiation. In this report there is discussion about the Scattering resonance that occurred in the terahertz band and these resonances are identified as the Fabry Perot resonance. In this paper there are some experimental results on the radiation scattering are analyzed in detail. Some simulation results show that these antennas can be used as a tunable terahertz antenna and its frequency can be changed through changing the substrate material and size.  (Llatser, Kremers, Cabellos-Aparicio, Jornet, Alarcón, & Chigrin., 2012)

According to the author Sharma he has given a design of Micro strip antenna through the use of hybrid fractal slot. This has been achieved through changing the length of the ground plane. The simulated results show that the bandwidth of the fabricated antenna is ideal and more reliable than that of simulated antenna because of this new technology (Sharma & Sharma, 2017).

PATCH, MICROSTRIP Antenna  

In telecommunication term these types of antenna also known as the printed antenna, the microstrip antennas are basically fabricated on the printed circuit boards. These antennas are used as microwave frequencies that these microwave frequencies are used in different mobile phone and radar system. The main characteristics of these antennas are they are cheaper in cost and these antennas can be fabricated easily.

The frequency of the patch antenna is given by

In this equation L is the length of the antenna,   is the relative permeability of the medium, c is the constant and this above equation gives information that the length of the antenna is equal to the half of the wavelength in the medium.

Relationship of Patch Antenna & resonant frequency

Resonant frequency of the microstrip antenna is that, where a radiation of antenna is maximum that is also called operating frequency of antenna. Resonant frequency of the patch microstrip antenna is calculated accurately because the patch antenna contains the narrow bandwidth that operates effectively in a vicinity of the resonant frequency. Resonance for the Patch antenna is the spectacle where the power feds goes to the patch by the less of power that being reflected back. [3]  

S-parameters for Two port Networks  

The most common parameters in antenna is S11. S11 shows that, how much power is reflected the antenna that is also called the reflection coefficient. (  If the S11 is equal to 0dB then the power is reflected from an antenna and nothing is radiated, and if S11 is equal to -10dB then its transfers to 3dB, that power is delivered to antenna of -7dB, is the reflected power. The two-port network is shown as below;

Figure 2: Two-port Network

S-matrix, for the scattering matrix, is represented as explained below;

Now the importance of the S11 parameters is explained in the one port network;

 Vector Network Analyzer & Working

This is used for testing the specification of the components and also involve in verifying design simulations. This is because it wants to enable complete systems and also ensure that all components work together. 

The vector network analyzer (VAN) works as the measure device, it measures the input signal that will be passed to the device under test and also that signal that will be measured after this input signal moves through the DUT. The main working of VNA is that it compares these two signals and then displays them on the external display.

 Figure 3: Working of VAN

Source:https://www.tek.com/dokument/primer/what-vector-network-analyzer-and-how-does-it-work

Design of Initial Patch Antenna

Figure 4: Design of initial Patch Antenna

Optimized Antenna 

Figure 5:  Optimized Antenna

Result of S11 on patch antenna

Results on patch antenna

This is the basic simulation results on CST  without VAN. The power that is reflected from the antena is represent as S11 that is also called as reflected coefficent