B 44 ˘ ˇ L B 1: R Ch (S m )

������� ����� ���� � ����� ���� ������� ���

B��44�� ������� ��� � �������

L�B 1: ������� R������� Ch� ���� ������ (S�m������)

Mapping CO, PO, Domain, KI : CO2, CO3, PO3, P5

CO2: Analyze the parameters of antenna such as radiation pattern, impedance,

directivity, gain, polarization

CO3: Design and evaluate various antennas to meet application requirements

PO3: Identify, formulate and provide effective solution to engineering problem

L�� ���� O���m��:

1. Model a microstrip antenna in CST Microwave Studio Software

2. Observe and analyze the radiation characteristic of a microstrip antenna

parameters using CST Microwave Studio Software.

M�� �� �� ������� B��k� ���

Microstrip antennas, also called patch antennas, are very popular antennas in the

microwave frequency range because of their simplicity and compatibility with circuit

board technology. The rectangular patch antenna is one of the most commonly used

microstrip antennas. Edge-fed microstrip antennas are suited to direct integration

with microstrip circuits, since the antenna can be etched on the same substrate. When

sharing a substrate with microstrip circuits, the antenna performance is, however,

limited by the conflicting substrate requirements for antenna and circuit use. This

antenna is popular as an array-element, but for large arrays the feed-network

radiation may affect performance considerably.

Figure 1: The Structure of a Microstrip Antenna

Physical Description

Edge-fed patch antennas are usually manufactured by etching the antenna patch

element and feed network in a metallised dielectric substrate. Larger antennas are

sometimes constructed by bonding metal cut-outs to a bare substrate.

Feed Method

An edge-fed patch antenna is fed by a microstrip feed line connected to the edge of the

patch. The microstrip feed line usually incorporates a quarter-wave transformer for

impedance matching.

Operation Mechanism

The patch can be seen as a resonant cavity [Balanis] with radiating slots at each end of

the patch. The fringing fields act to extend the effective length of the patch, thus, the

length of the half-wave patch is usually less than a half wavelength in the dielectric

medium.

S�m������ �� CST M�� w�v� D����� S����

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

1. Choose Project Template

2. Specify Units (� �q����� - GHz, T�m� – �� ��� D�m����� - �m)

3. Parameters + Geometry + Materials

4. Ports

5. Frequency-range + Boundaries / Symmetries

6. Monitor Definition

7. Quick Check Meshing

8. Run Simulation

Microstrip Antenna Modelling in CST Design Studio

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

2. Select a Workflow

3. Select units

4. Create new template

5. Construct Substrate

6. New materials properties

7. Create ground

8. Create Patch

9. Create Feed

10. Create Matching Line

11. Creating Matching Line

12. Create Patch

13. Complete Structure

14. Port Setting

15. Port Setting

16. Boundary Condition

17. Background Properties and Frequencies

18. Time Domain Simulations

19. S11 Results

20. E-field at 2.3 GHz

21. Far-field at 2.3 GHz