The document discusses reducing the size of planar microstrip antennas by varying slit dimensions. It aims to reduce antenna size and increase efficiency and gain. It analyzes different methods to reduce antenna size and identifies slot loading the patch as the best solution. Three antenna designs with different slit configurations are proposed, simulated, and tested. Results show the designs reduce antenna size by up to 8% while maintaining performance.

1. STUDY THE SIZE REDUCTION OF
PLANAR ANTENNA BY VARYING
SLIT DIMENSIONS

2. AIM
• To reduce the overall size of Microstrip planar
fed antenna.
• To increase the efficiency of antenna .
• To increase the gain of antenna .

3. OUTLINES• INTRODUCTION
• DEFINATION OF ANTEENA
• METHODS OF REDUCING PATCH ANTEENA
• GEOMETRY OF MICROSTRIP ANTENNA
• ANTENNA DESIGN
• RESULTS
• CONCLUSION
• REFRENCES

4. DEFINATION OF ANTENNA
• “ A usually metallic device for radiating or receiving radio waves.”
• “A transitional structure between free space and guiding device.”
ANTEENA RADIATION FORMULA USED
~
Zo
I
I
VG
+
-
Antenna
Structure
RF Signal
Source
Transmission
Line
Zo

5. METHODS OF REDUCING PATCH
ANTENNA
1. High Permittivity Substrate
2. Folded Patch
3. Shorting Pin
4. Slot Loaded Ground Plane
5. Slot Loaded Patch

6. 6
BEST SOLUTION-SLOT LOADED PATCH
1. High Permittivity Substrate:
 reduced BW, increased dielectric losses, increased cost
2. Folded Patch:
 increased volume, complex manufacturing process
3. Shorting Pin:
 problems with radiation pattern, feeding and manufacturing
tolerances
4. Slot Loaded Ground Plane:
 problems with back radiation, less transmission power
5. Slot Loaded Patch:
can produce wide range of designs:
Reduced Size Single Frequency, Dual Frequency, Wideband
1. High Permittivity Substrate:
 reduced BW, increased dielectric losses, increased cost
2. Folded Patch:
 increased volume, complex manufacturing process
3. Shorting Pin:
 problems with radiation pattern, feeding and manufacturing
tolerances
4. Slot Loaded Ground Plane:
 problems with back radiation, less transmission power
5. Slot Loaded Patch:
can produce wide range of designs:
Reduced Size Single Frequency, Dual Frequency, Wideband

7. GEOMETRY OF ANTENNA
Top view
Side view
PERFORMANCE
CHARACTERISTICS:
1. Return loss
2. Band width
3. Resonant frequency
4. Antenna efficiency
5. Radiation efficiency
6. Gain

8. ANTENNA DESIGN
REFERENCE ANTENNA
L=29.4mm, W=30 mm, єr=2.33,
h=1.57 mm
Performance characteristics
• Return loss of reference antenna : -12.89
•Resonant frequency : 3.202

9. OUR
PROPOSED
DESIGNS

10. PROPOSED DESIGN: 1
Antenna with two equal slits on width side

11. SIMULATION AND PRACTICAL RESULTS OF
DESIGN 1
Performance Characteristics
Due to increase in slit length following changes occur :
• Resonant frequency increases.
•Bandwidth also increases.
•Antenna efficiency & radiation efficiency increases.
•Gain increases .

13. PROPOSED DESIGN: 2
Antenna with three equal slits on width side and length side

14. SIMULATION AND PRACTICAL RESULTS OF
DESIGN 2
Performance Characteristics
Due to increase in width following changes occurs:
•Resonant frequency decreases.
• Return loss increases.
•Bandwidth decreases
•Antenna efficiency increases.
•Gain increases.

15. TOTAL DESIGN GAIN (dbi)

16. PROPOSED DESIGN :3
Antenna with four equal slits on length side

17. SIMULATION AND PRACTICAL RESULTS OF
DESIGN 3
Performance characteristics
Due to increase in length of slits following changes occur:
•Resonant frequency decreases.
•Bandwidth decreases.
•Antenna efficiency abruptly increases when length is 3mm & width is 2 mm.

18. TOTAL GAIN (dbi)

19. RESULTS
According to given equation frequency is inversely
proportional to length.
• In our first proposed antenna , frequency increases and to
decrease it we have to increase the length of antenna .
• In our second proposed antenna, frequency decreases and we
have decrease the size of antenna to increase the frequency.
• In our third proposed antenna we observed that there is
tremendous decrease in resonant frequency where as there is
steep increase in antenna efficiency .So to increase frequency
we have to reduce the size of antenna .

20. CONCLUSION
Focus on operating frequency to reduce the
size of patch is investigated . From the above
findings it is concluded that around 7-8 %
size reduction is possible, and no impedance
matching network is required for the size
reduction of proposed antenna .

21. REFERENCE
• [1] Dey, S., and Mittra, R.: ‘Compact microstrip patch
antenna’, Microw. Opt. Technol. Lett., 1996, 9, pp. 433–
434
• [2] C. A. Balanis, “Antenna Theory Analysis and Design”,
John Willy & Sons, 2nd Edition, C hipster 14,
pp.730734, 1997.
• [3]Wong, K.L., and Wu, J.Y.: ‘Single-feed small circular
polarised square microstrip antenna’, Electron. Lett.,
1997, 33, (22), pp. 1833–1834 2
• [4] Lu, J.H., and Wong, K.L.: ‘Slot-loaded, meandered
rectangular microstrip antenna with compact dual

22. •[5]George, J., Deepukumar, M., Aadandan, C.K.,
Mohanan, P., and Nair, K.G.: ‘New compact microstrip
antenna’, Electron. Lett., 1996, 32, pp.
•[6] W u, C.K., Wong, K.L., and Chen, W.S.: ‘Slot-
coupled meandered microstrip antenna’, Electron. Lett.,
1998, 34, pp. 1047–1048 6 Ansoft Ensemble1 V.7
method of moments 2.5D EM field solver
• [7] M . Elsdon, A. Sambell and Y. Qin ,’ Reduced size
direct fed planer antenna’, 2005
•[8] IE3D Software release 12.21 [Zeland software
Inc.,Fremont, California, USA].

23. PRESENTED BY:
S.K KUNDU
SACHIN SHARMA
SUMISHA JINDAL
 RASHMI MALLIK

24. Thank you for your attention