What is the radiation pattern of patch antenna?
The radiation pattern of microstrip or patch antenna is broad. It has low radiation power and narrow frequency bandwidth. To have a greater directivity, an array can be formed by using these patch antennas.
What is the gain of patch antenna?
A single patch antenna provides a maximum directive gain of around 6–9 dBi. It is relatively easy to print an array of patches on a single (large) substrate using lithographic techniques.
What is the resonant frequency of a patch antenna?
about 277 MHz
The size of the ground plane is 20 × 20 cm2. The return loss and radiation patterns are shown in Figure 10.37(a) and (b), respectively. The resonant frequency of the fabricated antenna is about 277 MHz, and it provides a wide bandwidth of about BW = 3.2%.
Is also called as 3 db bandwidth Mcq?
Explanation: half power bandwidth is also called the 3 db bandwidth.
Which condition makes coupled equations into uncoupled equations?
If the coefficient matrix is diagonal, then the system is uncoupled. If the coefficient matrix is not diagonal, then one of the corresponding differential equations involves two or more variables and the system is called coupled or cross-coupled.
How is antenna directivity calculated?
Antenna Directivity D = maximum radiation intensity of a test antenna / average radiation intensity of test antenna. Therefore D= 4 π(maximum radiation intensity)/total radiation power.
How does a patch antenna work?
Working of Patch Antenna. A microstrip or patch antenna operates in a way that when current though a feed line reaches the strip of the antenna, then electromagnetic waves are generated. The waves from the patch start getting radiated from the width side.
How do you measure antenna impedance?
For maximum power to be transferred from the generator to the antenna, the ideal value for the antenna impedance is given by: The * in the above equation represents complex conjugate. So if ZS=30+j*30 ohms, then for maximum power transfer the antenna should impedance ZA=30-j*30 ohms.
What is the radiation pattern of patch antennas?
Fundamental Specifications of Patch Antennas Radiation Pattern The patch’s radiation at the fringing fields results in a certain far field radiation pattern. This radiation pattern shows that the antenna radiates more power in a certain direction than another direction. The antenna is said to have certain directivity.
What is the permittivity of a patch antenna?
Consider a square patch antenna fed at the end as before in Figure 1a. Assume the substrate is air (or styrofoam, with a permittivity equal to 1), and that L = W =1.5 meters, so that the patch is to resonate at 100 MHz.
How do you reduce the impedance of a patch antenna?
For a square patch antenna fed in the manner above, the input impedance will be on the order of 300 Ohms. By increasing the width, the impedance can be reduced. However, to decrease the input impedance to 50 Ohms often requires a very wide patch antenna, which takes up a lot of valuable space.
What is the normalized radiation pattern for a microstrip antenna?
Figure 2. Normalized Radiation Pattern for Microstrip (Patch) Antenna. The directivity of patch antennas is approximately 5-7 dB. The fields are linearly polarized, and in the horizontal direction when viewing the microstrip antenna as in Figure 1a (we’ll see why in the next section).