Includes different types of Patch Antenna. Its feeding methods, rectangular patch antenna and remedies of using Patch Antenna .

1. Microstrip Patch Antenna
Presented by,
A.Priyanka

2. Patch Antenna
TopView of Patch Antenna Side view of Patch Antenna

3. Different shapes of antenna

4. Substrate
• The most commonly used substrates are,
1) Honey comb(dielectric constant=1.07)
2)RT Duroid(dielectric constant=2.32)
3)Quartz(dielectric constant=3.8)
4)Alumina(dielectric constant=10)
dielectric constant:
2.2≤𝝐 𝒓≤12

5. Feeding methods
Coaxial probe feedMicrostrip line feed

6. Feeding methods
Proximity coaxial feedAperture coupled feed

7. Comparing different feed techniques

8. Rectangular Patch Antenna
• The length of the patch is:
𝜆0
3
< 𝐿 <
𝜆0
2
• At low frequencies, initial vales of 𝝐 𝒓eff. referred to as the static values and are
given by:
𝝐 𝒓eff. =
𝝐 𝒓
+1
2
+
𝝐 𝒓
−1
2
[1+
12ℎ
𝑤
]-1/2
Where,
h= height of substrate
w= width of the patch

9. Rectangular Patch Antenna
• For an efficient radiator, practical width that leads to good radiator
efficiencies is:
W =
1
2𝑓𝑟 𝜇0
𝜖0
2
𝜖 𝑟
+1
=
𝑣0
2𝑓𝑟
2
𝜖 𝑟
+1
• For normalized extension of length:
∆𝐿
ℎ
= 0.412
(𝝐 𝒓eff.+0.3)(
𝑊
ℎ
+0.264)
(𝝐 𝒓eff.−0.258)(
𝑊
ℎ
+0.8)
Where,v0= free space velocity of light

10. Rectangular Patch Antenna
• Directivity of the single patch is:
D0 = {5. 2dB W<<𝜆0
4(
𝑊
𝜆0
) W>>𝜆0
• Finally, the effective length of the patch is:
Leff. = L+2 ∆𝐿
Where, ∆𝐿= extended length of the patch

11. Rectangular Patch Antenna
• The actual length of the patch can be determined by solving:
L =
1
2𝑓𝑟 𝝐 𝒓eff. 𝜇0
𝜖0
- 2 ∆𝐿
• Finally, the effective length of the patch is:
Leff. = L+2 ∆𝐿
Where, ∆𝐿= extended length of the patch

12. Remedies:
• Low power and low gain can overcome by arrays
configuration.
•The band width can increase up to 60% by using some
special techniques.
•Surface wave associated limitations such as poor
efficiency,increased mutual coupling , reduced gain and
radiation pattern can overcome.

13. Thank you