Antenna Design

Lab 10 - Inverted-L and inverted-F Antennas

I. Simulation

1. Monopole antenna

Monopole dimensions:

Feeding: Gap-fed with a discrete port with source impedance of 50 W

Design frequency:  f ₀ = (1000 + PIN/1000) MHz=1GHz

실습조교 PIN = 0000

Monopole axis: in z direction

Reference resonant dipole length: L = 0.45 λ = 0.45 ´ 300 = 135 mm

Monopole end-to-ground plane distance:  L/2 = 0.225 λ= 68 mm

Monopole diameter: d  = (L/2)/34 = 2.0 mm

Monopole feed gap: g/2 = d/2 = 1 mm

Monopole: PEC

Frequency range: 0.5f₀ to 1.5f₀

1-1. Plot the antenna structure.

1-2. Plot |S11| (dB) at 0.5f₀ to 1.5f₀.

1-3. Plot the imput impedance on the Smith chart.

1-4. On the Smith chart, mark the frequency f₀ and find the input impedance Z_in.

1-5. Plat 3D Gabs at f₀.

1-6. Find max(Gabs) at f₀.

2. Inverted-L antenna (ILA)

L₁ = 0.3 (L/2), L₂ = 0.7 (L/2), where L, g, and d are defined in the above.

2-1. Plot the antenna structure.

2-2. Plot |S11| (dB) at 0.5f₀ to 1.5f₀.

2-3. Plot the imput impedance on the Smith chart.

2-4. On the Smith chart, mark the frequency f₀ and find the input impedance Z_in.

2-5. Plat 3D Gabs at f₀.

2-6. Find max(Gabs) at f₀.

3. Inverted-F antenna (IFA)

L₁ = 0.3 (L/2), L₂ = 0.7 (L/2), where L, g, and d are defined in the above.

3-1. Plot the antenna structure.

With all other dimensions fixed, change S to the following vlaues

S = 2d, 4d, 6d, 8d, and 10d

using the parameter sweep method in CST Studio. If necessary, repeat the parameter sweep in smaller intervals for the lowest value of min{|S11| (dB)}.

3-2. Plot |S11|(dB) vs parameter S values.

Now set S = S_optimum and do the follwoing.

3-3. Plot |S11| (dB) at 0.5f₀ to 1.5f₀.

3-4. Plot the imput impedance on the Smith chart.

3-5. On the Smith chart, mark the frequency f₀ and find the input impedance Z_in.

3-6. Plat 3D Gabs at f₀.

3-7. Find max(Gabs) at f₀.

II. Discussions

Summarize your simulation in the follwing table.

Antenna	Frequency fC (GHz) for minimum |S11|	|S11| < -10 dB bandwidth (GHz)	Rin, Xin at fC.	Max (Gabs) at fC
Monopole
ILA
IFA