7/22/2019 Circular Horns-Patterns_ AE and GCE.ppt

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Conical Horn, flare angle = 14 deg.

0 20 40 60 80-10

-5

0

5

10

15

20

H-plane Angle (Degrees)

Directivity(

dB)

2 * lambda

2.5 * lambda

3 * lambda

0 20 40 60 80-10

-5

0

5

10

15

20

E-plane Angle (Degrees)

Directivity(

dB)

2 * lambda

2.5 * lambda

3 * lambda

0 20 40 60 80-30

-25

-20

-15

-10

-5

0

H-plane Angle (Degrees)

NormalizedDirectivity(dB)

2 * lambda

2.5 * lambda

3 * lambda

0 20 40 60 80-30

-25

-20

-15

-10

-5

0

E-plane Angle (Degrees)

NormalizedDirectivity(dB)

2 * lambda

2.5 * lambda

3 * lambda

1.5 2 2.5 3 3.50

20

40

60

80

Aperture Size (Wavelengths)

Beamwidth(Degrees)

3 dB (E)

3 dB (H)

10 dB (E)

10 dB (H)

7/22/2019 Circular Horns-Patterns_ AE and GCE.ppt

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Conical Horn, flare angle = 14 deg.

1.5 2 2.5 3 3.50

0.2

0.4

0.6

0.8

1

Aperture Size (wavelengths)

PlaneWaveCouplingCoefficient

1.5 2 2.5 3 3.50

0.2

0.4

0.6

0.8

1

Aperture Size (wavelengths)

PlaneWaveCouplingCoefficient

0.2 0.4 0.6 0.8 1 1.2 1.40

0.2

0.4

0.6

0.8

1

Gaussian Beam Waist / Aperture Size

GaussianCouplingEfficiency

0.2 0.4 0.6 0.8 1 1.2 1.40

0.2

0.4

0.6

0.8

1

Gaussian Beam Waist / Aperture Size

GaussianCouplingEfficiency

0.5 1 1.5 2 2.5 30

0.2

0.4

0.6

0.8

1

Gaussian Beam Waist (wavelengths)

GaussianCou

plingEfficiency

2 * lambda

2.5 * lambda

3 * lambda

0.5 1 1.5 2 2.5 30

0.2

0.4

0.6

0.8

1

Gaussian Beam Waist (wavelengths)

GaussianCou

plingEfficiency

2 * lambda

2.5 * lambda

3 * lambda A 2-3lcircular horn with a flare angle

of 14 deg. results in excellent patterns

with low sidelobes, an aperture efficiencyof 0.9-0.82 (coupling to a plane wave),

and a Gaussian coupling efficiency of 88-

90% (coupling to a lens).

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Conical Horn, flare angle = 27 degrees

0 20 40 60 80-30

-25

-20

-15

-10

-5

0

E-plane Angle (Degrees)

NormalizedDirectivity(dB)

2 * lambda

2.5 * lambda

3 * lambda

0 20 40 60 80-30

-25

-20

-15

-10

-5

0

H-plane Angle (Degrees)

NormalizedDirectivity(dB)

2 * lambda

2.5 * lambda

3 * lambda

0 20 40 60 80-10

-5

0

5

10

15

20

E-plane Angle (Degrees)

Directivity

(dB)

2 * lambda

2.5 * lambda

3 * lambda

0 20 40 60 80-10

-5

0

5

10

15

20

H-plane Angle (Degrees)

Directivity

(dB)

2 * lambda

2.5 * lambda

3 * lambda

1.5 2 2.5 3 3.50

20

40

60

80

Aperture Size (Wavelengths)

Beamwidth(Degrees)

3 dB (E)

3 dB (H)10 dB (E)

10 dB (H)

1.5 2 2.5 3 3.50

20

40

60

80

Aperture Size (Wavelengths)

Beamwidth(Degrees)

3 dB (E)

3 dB (H)10 dB (E)

10 dB (H)

1.5 2 2.5 3 3.50

20

40

60

80

Aperture Size (Wavelengths)

Beamwidth(Degrees)

3 dB (E)

3 dB (H)10 dB (E)

10 dB (H)

7/22/2019 Circular Horns-Patterns_ AE and GCE.ppt

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Conical Horn, flare angle = 27 degrees

0.2 0.4 0.6 0.8 1 1.2 1.40

0.2

0.4

0.6

0.8

1

Gaussian Beam Waist / Aperture Size

GaussianCoupling

Efficiency

0.5 1 1.5 2 2.5 30

0.2

0.4

0.6

0.8

1

Gaussian Beam Waist (wavelengths)

GaussianCoup

lingEfficiency

2 * lambda

2.5 * lambda

3 * lambda

1.5 2 2.5 3 3.50

0.2

0.4

0.6

0.8

1

Aperture Size (wavelengths)

PlaneWaveCouplin

gCoefficient

A 2-3lcircular horn with a flare angle

of 27 deg. results in good pattern for all

dimensions, an aperture efficiency of

0.78-0.62 (coupling to a plane wave is

still good since this is a circular apertureand the max. phase error on thesquare-

edges sees a zero E-field). The

Gaussian coupling efficiency is 88%

(coupling to a lens) since one can choose

the location in the focal plane lens of the

lens to compensate for the phase erroron the aperture of the horn.