Microwaves can be used to find water impurities like salinity i.e. hardness, Chlorinity, etc. A simple system (prototype) is being designed and tested in this ppt. for measuring salinity of water. This work is done with the help of by Gov. of India's SAMEER organisation as well as Gov. of Maharashtra's Irrigation Department.

1. Project Seminar on
Water Salinity Measurement System
Using Microwaves
Presented by;
Sanket S.Yavalkar
P.G. Student (EXTC) (Enrollment No.138)
Sardar Patel Institute of Technology, Mumbai
1
Under Guidance of
Dr.S.S.Rathod
22 October 2013

2. Contents
 Aim and Objectives
 Project Motivation
 Literature Survey
 Water Salinity System Introduction
 Need of Work
 Antennas
 Design of Patch Antenna
 Parametric Study of Patch Antenna
 Salinity and Various Salinity Measurement Systems
 Microwaves Based Water Salinity Measurement System
 Proposed System
2
 Conclusion
22 October 2013

3. Aim
 To design the patch antenna to use it for Salinity Measurement
System
Objective
 To study antennas.
 Study Salinity Measurement Systems.
 Study and Design a Patch Antenna.
 Use that antenna for Measuring Salinity of Water.
3

4. Project Motivation
Actual Photograph of Bore-well of water
Water to be Tested
4
22 October 2013

5. Literature Survey
 Patch Antennas
 James Maxwell and Ruolph Hertz are the one who described
the electromagnetic waves in 18th century [1-2].
 Antennas are the one which are first studied and developed by
Guglielmo Marconi in the first few years of 20th century [3].
 In year 1979, the microstrip patch antennas were proposed by,
Munson R. with Joy E., in which they proposed the planer endfire antennas [4].
 The present technology of printed antennas points to use of
available structures and designs.
5
22 October 2013

6. Literature Survey
 Salinity Measurement System
 First published work was by famous chemist Robert Boyle in
17th century about “Observations and Experiments on Saltiness
of SeaWater,” cleared up some ideas about salt.
 In 18th century, Mist chemists Hitherto had evaporated the
water to find out salt contents.
 Between 1843 and 1865 the Danish chemist, J.G.Forchhammer
published several milestone papers on the compostion of sea
water. His techniques were gravimetric; he did not use the
evaporation method. He used data from all over the world, and
compared his results for these different waters. Forchhammer
introduced the word „Salinity‟.
6
22 October 2013

7.  In the years 1873-1876 H.M.S. Challenger sailed almost 69,000
miles about the world making oceanography observations.
Seventy-seven salinity samples were collected from various
depths. They were analysed by W.Dittmar, in “the most
extensive sea water analysis performed before, or since.”
 The concepts noted above were generally accepted by the late
19th century but the man behind the coefficients of chlorine and
specific gravity were uncertain.
 Chlorine content of the samples was determined by titration
using the Mohr method by the Swedish chemist, S. P. L.
Sorensen in 1901. The equation relating salinity and chlorinity
(S=1.805CL+0.030) was stated by him from his observations.
7
22 October 2013

8.  Knudsen determined the specific weights of the samples. C. Forch
determined the volume expansion of sea water. In a remarkably short
time the results of these studies were published in the famous
"Hydrographical Tables", of 1901 relating chlorinity, salinity and density
of sea water.These tables have been in use for seventy years
 Since 1955 salinity determination by measuring the electrical
conductivity of sea water has come into prominence until at
present many more determinations of salinity are made by the
conductivity measurements than by chemical titrations.
 The latest instruments are almost as sensitive as the best
laboratory salinometers but because of the operating environment
are rated by the manufacturer as giving an accuracy of about
0.01‰ in salinity. [5]
8
22 October 2013

9. Water Salinity Measurement

9

10. Need of Work
 Effect of use of salty water
 Agriculture
 Agriculture is not possible on saline
Land.
 Society
 Quality of Construction
 Dams Construction
 Health
 kidney disease
 kidney stones
 high blood pressure
10
Saline Land(Courtesy : Google Image)
Use of Saline Water for Construction
( Courtesy : Google Image )22 October 2013

11. Salinity Measurement Systems

11
22 October 2013

12. Microwave Based Salinity Measurement
System

12
22 October 2013

13. Antenna is transducers (it
converts one from of energy
in to another) that transmit
or receive electromagnetic
waves (has electric and
magnetic field component
which oscillate in phase
perpendicular to each other
and to the direction of
energy propagation).
Antenna???

14. Comparison Of Different Antenna
Radiation
Power
Gain
Polarization
Patterns
Dipole
Broadside
Low
Low
Linear
Multi Element
Broadside
Low/medium
Low
Linear
Broadside
Medium
Medium/high
Linear/circular
Broadside
High
High
Linear/circular
Yagi Antenna
Endfire
Medium/high
Medium/high
Linear
Slotted Antenna
Broadside
Low/medium
Low/medium
Linear
Microstrip
Endfire
Medium
Medium
Linear/circular
Dipole
Flat Panel
antenna
Parabolic Dish
Antenna
antenna

15. Basic form of Patch Antenna

16. Design of Patch Antenna

16

17. Transmission Line Model

17
22 October 2013

18. 
18
22 October 2013

19. Design of Patch Antenna
 Antenna Specifications
Parameters
Length
Width
45 mm
Ground Plane Length
110 mm
Ground Plane Width
90 mm
Height
1.56 mm
Substrate
FR4
Dielectric Constant
4.47
Loss Tangent
0.02
Resonance Frequency
19
55.5 mm
1.57 GHz

20. Parametric Study of Patch Antenna
 Effect of Height
 Effect of Width
 Effect of Dielectric Constant
 Effect of Loss Tangent
 Effect of Feed Location
20
22 October 2013

21.  Effect of Height
0
-2
Return Loss (dB)
-4
-6
-8
-10
-12
-14
-16
Height = 3 mm
Height = 1.5 mm
-18
-20
1.48
1.50
1.52
1.54
1.56
1.58
1.60
1.62
Frequency (GHz)
Discussion : With an increase in h from 1.5 mm to 3 mm, the following
effects are observed:
•Resonance frequency decreases
•The BW of the antenna increases
•BW is directly proportional to height(h)

22.  Effect of Width
0
-2
Return Loss (dB)
-4
-6
-8
-10
-12
Width = 44.5
Width = 43.5
-14
-16
-18
1.4
1.5
1.6
1.7
1.8
1.9
2.0
2.1
Frequency (GHz)
Discussion : With an increase in W from 43.5 mm to 44.5 mm, the following
effects are observed:
• Resonance frequency decreases from 1.64 GHz to 1.57 GHz
• BW of the antenna increases

23.  Effect of Dielectric Constant
0
-2
Return Loss (dB)
-4
-6
-8
-10
-12
r =1
r =2.2
r =4.4
-14
-16
-18
1.48
1.50
1.52
1.54
1.56
1.58
1.60
1.62
Frequency (GHz)
Discussion:
Єr is decreased to 1, the resonance frequency increases. A better
comparison of effect of Єr is obtained when the antenna is designed to
operate in the same frequency range for different values of Єr .

24.  Effect of Loss Tangent
0
Return Loss (dB)
-5
-10
-15
-20
tan  = 0.02
tan  = 0.001
-25
-30
-35
1.48
1.50
1.52
1.54
1.56
1.58
1.60
1.62
Frequency (GHz)
Discussion:
It is observed that lesser the loss tangent the less the loss in the
probe.
24
22 October 2013

25.  Effect of Feed Location
0
-2
Return Loss (dB)
-4
-6
feed at (10,6)
feed at (10,12)
feed (10,7)
feed (10,8)
feed (10,9)
feed (10,10)
-8
-10
-12
-14
-16
-18
1.560
1.565
1.570
1.575
1.580
Frequency (GHz)
• The feed point at (10,8)giving most negative RL

26.  Conclusion From Parametric Study of Above Design of
Antenna
Change In
Parameters
Feed
Location
Height
Width
εr
Loss Tangent
26
Resonance
Frequency
No shift
Bandwidth
Increases
Decreases
Decreases
Increases
Increases
Decreases
Decreases
Decreases
No Chage

27. Manufactured Antenna
Parameters
Length
Width
45 mm
Ground Plane Length
110 mm
Ground Plane Width
90 mm
Height
1.56 mm
Substrate
FR4
Dielectric Constant
4.47
Loss Tangent
0.02
Resonance Frequency
27
55.5 mm
1.57 GHz

28. Measured Results
0
Return Loss (dB)
-10
-20
-30
-40
-50
1.555
Simulated Results
Measured Results
1.560
1.565
1.570
1.575
Frequency (GHz)
Frequency (GHz)
28
Resonance
Frequency
Bandwidth
Simulated
Results
1.5710GHz
Measured
Results
1.5760GHz
+5MHz
1.11%
1.27%
-0.16%
Error
1.580
1.585

29. Salinity and Unit to Measure Salinity

29

30. Salinity Measurement Methods
1. Gravimetric Determination
1.
2.
3.
Take a known amount of salty water.
Evaporate it to dryness
Weigh the remaining salts
Limitations :
1. Residue left after evaporation is a complex mixture of
salts together with some water of hydration bound to the
solids, plus a small amount of organic material
2. So produces unreliable results
30

31. Salinity Measurement Methods

31

32. Salinity Measurement Methods

32

33. Use of Microwaves for salinity
Measurement

33

34. Use of Microwaves for salinity
Measurement
 Salt is composed of sodium chloride (NaCl)
 Pure water is poor conductor of electricity.
 But the ions of NaCl with water increases conductivity of




34
water.
So skin depth decreases as salt percentage in water increases.
EM waves totally degrade after a distance equal to skin depth
One can measure attenuation of EM waves using various
instruments like network analyser, spectrum analyser, etc.
We can build up a relation in attenuation of EM waves with
percentage salt content in water.

35. Methodology
Transmitting
Antenna
Sample
Holder/Cavity
Signal
Generator
Spectrum
Analyser
Receiving Antenna
Water Samples
Analog Input
File
Firmware/
Software
35

36. Procedure :
Take pure form of water or take
water whose contents are known
Take a patch antenna having cavity above its
conducting patch. Use as a receiver.
Use another antenna without cavity as a
transmitting antenna
Measure the
attenuation with
air in cavity.
Store Result
for Reference.
Pour the Pure form of water in the cavity
Measure the
attenuation
Store Result
for Reference
Pour known quantity of salt (sample 1..n )in
pure water
Measure as many samples as one can to have
many references for calibration.
36
Use calibrated data as a reference during
actual measuring of salinity at field.

37. Apparatus Required
 Transmitting Antenna and Receiving Antenna
 Spectrum Analyser
 Signal Generator
 Sample Holder
37

38. Experimental Setup
38

39. Results and Discussion
Sample
Without
Water
Sample 1
Sample 2
Sample 3
Sample 4
Sample 5
39
% of Attensalt in uation
water (dBm)
-10.35
0
2.5
5
7.5
10
-30.04
-34.86
-35.98
-38.24
-44.23

40. Proposed Indigenous offline Water
Salinity System
1.57 GHz
Oscillator
1.50 GHz
Oscillator
Power
Amplifier
Mixer
Isolator
LNA
Patch
Antenna
Rx
Patch Antenna
Tx
Sample
Holder/
Cavity
BPF
1.57GHz
BPF
70MHz
IF
Amplifier
Coupler
1
A1
DC
Ampl.
Ampl.
Detector
Data Acquisition
Unit
Computer
40

41. Firmware
(a) Operational Mode
41

42. Applications
Salinity Measurement
2. Impurity of Water Measurement
3. Soil Moisture Measurement
4. Grains Moisture Measurement
1.
42
22 October 2013

43. Conclusion
 Patch antenna is studied and designed.
 Analytical Study of Patch Antenna.
 Parametric study of patch antenna.
 Various Salinity Measurement System are studied.
 Implementation of Microwave based Offline Salinity
Measurement System using Patch antennas.
 Offline Salinity Measurement System is proposed.
43

44. Future Work
 A better calibration scheme will make the system better.
 The use system can be further expanded by using it not only
for salt measurement but also impurity measurement in
water.
44

45. Publications
1.
2.
3.
45
S.S.Yavalkar, R.T.Dahatonde, S.S.Rathod, S.B.Deosarkar, “Comparative
Analysis of Bandwidth Enhancement of Microstrip Patch Antenna using
Various Geometries,” IOSR Journal,Vol.3, Issue 4, pp.Sep.2012
S.S.Yavalkar, R.T.Dahatonde, S.S.Rathod, S.B.Deosarkar, “Parametric Study
of Rectanguar Microstrip Antenna,” IOSR Journal,Vol.5, Issue 2,pp.4953,Apr. 2013.
S.S.Yavalkar, R.T.Dahatonde, S.S.Rathod, “Water Salinity Measurement
Using Patch Antennas,” INDICON-2013, Mumbai, (communicated)
22 October 2013

46. References
[1] Maxwell James Clerk, “A dynamic Theory of Electromagnetic Field,”
Philosophical Transaction of the Royal Society of London,1865.
[2] Heinrich Hertz, “Electric Waves: Being Researches on the Propagation of
Electric Action with Finite Velocity Through Space,” Dover Publications, 1893.
[3] Bondyopadhyay,K. Prebir, "Guglielmo Marconi – The father of long distance
radio communication – An engineer's tribute,"25th European Microwave
Conference,pp.879, 1995.
[4] Munson, R. Joy, E., “Microstrip antenna technology at ball aerospace systems,
Boulder, Colorado,” Antennas and Propagation IEEE society newsletter, Vol.21 pp.4 6, June 1979.
[5] E.R.Walkar, Salinity in Physical Oceanography, Pacific Marine Science
Report,Institute of Ocean Science,Victoria B.C., pp.21-76, Sept. 1976.
[6] Practical Salinity Scale, Unesco,1979
[7] Ghassemi F., Jakeman A.J., Nix H.A., Stalinisation of land and water
resources: Human causes, extent, management and case studies, UNSW Press,
Sydney, Australia, and CAB
46
22 October 2013

47. Thank You !!!
47

48. 48
22 October 2013

49. 49
22 October 2013

50.  Effect of Feed Location
0
-2
Return Loss (dB)
-4
-6
feed at (10,6)
feed at (10,12)
feed (10,7)
feed (10,8)
feed (10,9)
feed (10,10)
-8
-10
-12
-14
-16
-18
1.560
1.565
1.570
1.575
1.580
Frequency (GHz)
Discussion :
50
• Minimum Return Loss (RL) occurs at feed-location
(10,8).
•There is only one feed point where RL is minimum.
22 October 2013

51.  Effect of height
0
-2
Return Loss (dB)
-4
-6
-8
Height = 3 mm
Height = 1.5 mm
-10
-12
-14
-16
-18
-20
1.48
1.50
1.52
1.54
1.56
1.58
1.60
1.62
Frequency (GHz)
51
Discussion : With an increase in h from 1.5 mm to 3 mm, the following
effects are observed:
•Resonance frequency decreases
•The BW of the antenna increases
22 October 2013
•BW is directly proportional to height(h)

52.  Effect of Dielectric Constant
0
-2
Return Loss (dB)
-4
r =1
r =2.2
r =4.4
-6
-8
-10
-12
-14
-16
-18
1.48
1.50
1.52
1.54
1.56
1.58
1.60
1.62
Frequency (GHz)
52
Discussion:
Єr is decreased to 1, the resonance frequency increases. A better
comparison of effect of Єr is obtained when the antenna is designed to
22
operate in the same frequency range for different values of ЄrOctober 2013
.

53.  Effect of Width
Discussion:
•The resonance frequency decreases from 1.64 GHz to 1.57 GHz due to
the increase in ∆L and Єe.
•The BW of the antenna increases; however, it is not very evident from
these plots, because the feed point is not optimum for the different
22 October 2013
53
widths

54.  Effect of Shape
Parameters
RMSA
L-Shape
S-Shape
Geometry
Return Loss
Bandwidth
54
-20 dB
30MHz
-15 dB
35MHz
-30dB
40 MHz
22 October 2013

55.  Effect of Shapes
55
22 October 2013

56.  Fractal Antenna Design
1. Iteration 1
2. Iteration 2
56
22 October 2013

57. 3. Iteration 3
57
22 October 2013

58. Plan of Work
Current Work
Till now different BW enhancement methods were studied and implemented.
The methods
till studied are :
1. Use of thicker substrate or use of stacked patches.
2. Use of slots.
3. Fractal design of patch.
Remaining Work
There are still some more methods to be studied for enhance the BW. These
are like :
1. Suspended design of fractal.
2. Monopole patch antenna.
58
22 October 2013

59. Thank You !!!
59
22 October 2013

60. Analysis of RMSA using
Transmission line Model
60
22 October 2013