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Faculty of Electrical & Electronics Engineering BEE4433 Antenna and Propagation Lab 2: Broadband Antenna Characteristics (Horn Antenna) CO PO Mapping CO2: Design and evaluate various antennas to meet application requirements. PO4: Investigation - Conduct investigation of complex electronics engineering problems using research-based knowledge and research methods including design of experiments, analysis and interpretation of data, and synthesis of information to provide valid conclusions. Learning Outcomes: a) Model a horn antenna in CST Microwave Studio Software b) Observe and analyze the radiation characteristic of a horn antenna parameters using CST Microwave Studio Software. Horn Antenna Background The horn antenna is used in the transmission and reception of RF microwave signals, and the antenna is normally used in conjunction with waveguide feeds. Physical Description The horn antenna gains its name from its appearance. The waveguide can be considered to open out or to be flared, launching the signal towards the receiving antenna. Horn antennas are often used as gain standards, and as feeds for parabolic or 'dish' antennas, as well as being used as RF antennas in their own right. One particular use of horn antennas themselves is for short range radar systems, such as those used for automotive speed enforcement. When used as part of a parabolic reflector, the horn is orientated towards the reflector surface, and is able to give a reasonably even illumination of the surface without allowing radiation to miss the reflector. In this way it is able to maximize the efficiency of the overall antenna. The use of the horn antenna also minimizes the spurious responses of the parabolic reflector antenna to signals that are not in the main lobe.

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Page 1: Faculty of Electrical & Electronics Engineering BEE4433 Antenna …ee.ump.edu.my/hazlina/teaching_ANT/LAB_EVA_lab2_CSTHorn.pdf · 2019. 2. 18. · using CST Microwave Studio Software

Faculty of Electrical & Electronics Engineering

BEE4433 Antenna and Propagation

Lab 2: Broadband Antenna Characteristics (Horn Antenna)

CO PO Mapping CO2: Design and evaluate various antennas to meet application requirements. PO4: Investigation - Conduct investigation of complex electronics engineering

problems using research-based knowledge and research methods including design of experiments, analysis and interpretation of data, and synthesis of information to provide valid conclusions.

Learning Outcomes: a) Model a horn antenna in CST Microwave Studio Software b) Observe and analyze the radiation characteristic of a horn antenna parameters

using CST Microwave Studio Software.

Horn Antenna Background The horn antenna is used in the transmission and reception of RF microwave signals, and the antenna is normally used in conjunction with waveguide feeds.

Physical Description The horn antenna gains its name from its appearance. The waveguide can be considered to open out or to be flared, launching the signal towards the receiving antenna. Horn antennas are often used as gain standards, and as feeds for parabolic or 'dish' antennas, as well as being used as RF antennas in their own right. One particular use of horn antennas themselves is for short range radar systems, such as those used for automotive speed enforcement. When used as part of a parabolic reflector, the horn is orientated towards the reflector surface, and is able to give a reasonably even illumination of the surface without allowing radiation to miss the reflector. In this way it is able to maximize the efficiency of the overall antenna. The use of the horn antenna also minimizes the spurious responses of the parabolic reflector antenna to signals that are not in the main lobe.

Page 2: Faculty of Electrical & Electronics Engineering BEE4433 Antenna …ee.ump.edu.my/hazlina/teaching_ANT/LAB_EVA_lab2_CSTHorn.pdf · 2019. 2. 18. · using CST Microwave Studio Software

There are two basic types of horn antenna: pyramid and conical. The pyramid ones, as the name suggests are rectangular whereas the corrugated ones are usually circular. The corrugated horn provides a pattern that is nearly symmetrical, with the E and H plane beam widths being nearly the same. Additionally it is possible to control the side lobes better with a conical or corrugated horn antenna. The horn antenna is a particularly useful form of antenna for use with RF microwave applications and waveguide feeder. Although it is not used below RF microwave frequencies because waveguides are not used at low frequencies as a result of the sizes needed, the horn antenna is nevertheless a very useful form of RF antenna design for use at high frequencies.

Figure 1: The Structure of a Horn Antenna

Operation Mechanism The horn antenna may be considered as an RF transformer or impedance match between the waveguide feeder and free space which has an impedance of 377 ohms. By having a tapered or having a flared end to the waveguide the horn antenna is formed and this enables the impedance to be matched. Although the waveguide will radiate without a horn antenna, this provides a far more efficient match. In addition to the improved match provided by the horn antenna, it also helps suppress signals travelling via unwanted modes in the waveguide from being radiated. However the main advantage of the horn antenna is that it provides a significant level of directivity and gain. For greater levels of gain the horn antenna should have a large aperture. Also to achieve the maximum gain for a given aperture size, the taper should be long so that the phase of the wave-front is as nearly constant as possible across the aperture. However there comes a point where to provide even small increases in gain, the increase in length becomes too large to make it sensible. Thus gain levels are a balance between aperture size and length. However gain levels for a horn antenna may be up to 20 dB in some instances.

Page 3: Faculty of Electrical & Electronics Engineering BEE4433 Antenna …ee.ump.edu.my/hazlina/teaching_ANT/LAB_EVA_lab2_CSTHorn.pdf · 2019. 2. 18. · using CST Microwave Studio Software

Simulation in CST Microwave Design Studio

Good Habit 1. SAVE EARLY AND OFTEN

2. CST is notorious for crashing at the most inopportune times. Do yourself a favor and save in your flash memory.

3. Make sure all components/structures are connected. Loose wires are a frequent cause of problems.

4. Try your hand at debugging first before calling me . You will learn a lot by struggling through problems that seem hard at first.

5. Read all background behind the antenna and the lab instructions carefully before starting the lab. Often, there will be a little detail that ends up being very important.

CST Work Flow

6. Choose Project Template

7. Specify Units (Frequency - GHz, Time – ns and Dimension - cm)

8. Parameters + Geometry + Materials

9. Ports

10. Frequency-range + Boundaries / Symmetries

11. Monitor Definition

12. Quick Check Meshing

13. Run Simulation

Horn Antenna Modelling in CST Design Studio

Page 4: Faculty of Electrical & Electronics Engineering BEE4433 Antenna …ee.ump.edu.my/hazlina/teaching_ANT/LAB_EVA_lab2_CSTHorn.pdf · 2019. 2. 18. · using CST Microwave Studio Software

1. Click “create project” and then select “Antennas”, then click “Next”

2. Select a Workflow

Page 5: Faculty of Electrical & Electronics Engineering BEE4433 Antenna …ee.ump.edu.my/hazlina/teaching_ANT/LAB_EVA_lab2_CSTHorn.pdf · 2019. 2. 18. · using CST Microwave Studio Software

3. Select units

4. New template summary - verify

Page 6: Faculty of Electrical & Electronics Engineering BEE4433 Antenna …ee.ump.edu.my/hazlina/teaching_ANT/LAB_EVA_lab2_CSTHorn.pdf · 2019. 2. 18. · using CST Microwave Studio Software

5. Background Material, Set Frequency

Page 7: Faculty of Electrical & Electronics Engineering BEE4433 Antenna …ee.ump.edu.my/hazlina/teaching_ANT/LAB_EVA_lab2_CSTHorn.pdf · 2019. 2. 18. · using CST Microwave Studio Software

6. Construct Horn Antenna

7. Continue to construct Horn Antenna structure

Page 8: Faculty of Electrical & Electronics Engineering BEE4433 Antenna …ee.ump.edu.my/hazlina/teaching_ANT/LAB_EVA_lab2_CSTHorn.pdf · 2019. 2. 18. · using CST Microwave Studio Software

8. Use function Shell

9. Define Port

Page 9: Faculty of Electrical & Electronics Engineering BEE4433 Antenna …ee.ump.edu.my/hazlina/teaching_ANT/LAB_EVA_lab2_CSTHorn.pdf · 2019. 2. 18. · using CST Microwave Studio Software

10. Boundary Condition

Page 10: Faculty of Electrical & Electronics Engineering BEE4433 Antenna …ee.ump.edu.my/hazlina/teaching_ANT/LAB_EVA_lab2_CSTHorn.pdf · 2019. 2. 18. · using CST Microwave Studio Software

11. Set 3D Monitors

12. Mesh View

13. Start Transient Solver

Page 11: Faculty of Electrical & Electronics Engineering BEE4433 Antenna …ee.ump.edu.my/hazlina/teaching_ANT/LAB_EVA_lab2_CSTHorn.pdf · 2019. 2. 18. · using CST Microwave Studio Software

14. Analyze 1D results

15. Analyze 2D results

Page 12: Faculty of Electrical & Electronics Engineering BEE4433 Antenna …ee.ump.edu.my/hazlina/teaching_ANT/LAB_EVA_lab2_CSTHorn.pdf · 2019. 2. 18. · using CST Microwave Studio Software

16. Electric Field at 10 GHz

Page 13: Faculty of Electrical & Electronics Engineering BEE4433 Antenna …ee.ump.edu.my/hazlina/teaching_ANT/LAB_EVA_lab2_CSTHorn.pdf · 2019. 2. 18. · using CST Microwave Studio Software

17. Farfield at 10 GHz

Page 14: Faculty of Electrical & Electronics Engineering BEE4433 Antenna …ee.ump.edu.my/hazlina/teaching_ANT/LAB_EVA_lab2_CSTHorn.pdf · 2019. 2. 18. · using CST Microwave Studio Software

18. Polar Plot at 10 GHz

19. Parameterization

20. Parameterization

Page 15: Faculty of Electrical & Electronics Engineering BEE4433 Antenna …ee.ump.edu.my/hazlina/teaching_ANT/LAB_EVA_lab2_CSTHorn.pdf · 2019. 2. 18. · using CST Microwave Studio Software

21. Result Processing Template

22. Result Processing Template

Page 16: Faculty of Electrical & Electronics Engineering BEE4433 Antenna …ee.ump.edu.my/hazlina/teaching_ANT/LAB_EVA_lab2_CSTHorn.pdf · 2019. 2. 18. · using CST Microwave Studio Software

23. Result Processing Template

24. Parameter Sweep setting

Page 17: Faculty of Electrical & Electronics Engineering BEE4433 Antenna …ee.ump.edu.my/hazlina/teaching_ANT/LAB_EVA_lab2_CSTHorn.pdf · 2019. 2. 18. · using CST Microwave Studio Software

25. Parameter Sweep Results

Page 18: Faculty of Electrical & Electronics Engineering BEE4433 Antenna …ee.ump.edu.my/hazlina/teaching_ANT/LAB_EVA_lab2_CSTHorn.pdf · 2019. 2. 18. · using CST Microwave Studio Software
Page 19: Faculty of Electrical & Electronics Engineering BEE4433 Antenna …ee.ump.edu.my/hazlina/teaching_ANT/LAB_EVA_lab2_CSTHorn.pdf · 2019. 2. 18. · using CST Microwave Studio Software

Evaluation Lab 2 (5%) Print this and present it to me when you demonstrate your work.

CO2: Design and evaluate various antennas to meet application requirements. PO4: Investigation - Conduct investigation of complex electronics engineering problems

using research-based knowledge and research methods including design of experiments, analysis and interpretation of data, and synthesis of information to provide valid conclusions.

Requirement Points Complete the lab on time /1 Show horn antenna structure /2 Show simulation results 2D - polar plot /2 Show parameter sweep results /2 Answer correctly /3 Total /10

1. Describe the operating bandwidth of the horn antenna.

2. What are the parameters that influence the operating frequency of the antenna?

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