ANT-20G Series

Goniometers

ANT-20G Series nano Motion Technology
Direct Drive, High-Performance
Goniometers
Noncontact, non-cogging, frictionless directdrive for zero backlash or hysteresis
High speed (150°/s)
High resolution (0.1 arc second)
Excellent in-position stability
Large angular range; 20° of travel
Orthogonal mounting of two cradles provides
rotation about the same point
No maintenance

Clockwise from upper
left: ANT-20G-50
mounted in an
orthogonal configuration
with an ANT-20G-90,
ANT-20G-110, and an
ANT-20G-160.

U.S. Patent No. 6,442,851

Compact design4.5

20

4.0

17.5

3.5

15

3.0

12.5

2.5

10

2.0

7.5

1.5

5

1.0

2.5

0.5

00

-2.5

05

1015Time (s)2025Position (arc sec)

High-precision bearings, direct on-axis encoder feedback,and noncontact and noncogging direct-drive technology
assure the highest level of performance and make excellent
repeatability and in-position stability a reality. The
goniometer cradles can be mounted orthogonally to provide
pitch and roll about the same point in space. Combining thiswith a rotary stage under the orthogonal assembly adds athird rotation axis (pitch, roll, yaw) through the same point.

ANT-20G-90 2.5 µrad or 0.5 arc sec step size

22.5

Position (µrad)

Aerotech’s ANT-20G goniometers represent a significant
breakthrough in the high-accuracy angular alignment ofcomponents. This unique design utilizes Aerotech’s best-inclass direct-drive noncontact motor technology. When usedwith Aerotech’s controllers, the ANT-20G series provides
an industry-leading positioning speed of 150 degrees per
second.

-0.5

ANT-20G-90 step plot. Best-in-class resolution andexceptional in-position stability for large angular travel
stages.

The critical elements of the ANT-20G goniometers, as withall other ANT series nanopositioners, were selected tooperate in a 24/7 manufacturing environment. Unlike
worm- or piezo-driven goniometers, the ANT-20G series
will not require periodic adjustment or maintenance. This
will assure many years of trouble-free operation. The ANT20G cradles are available in four sizes.

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ANT-20G Series SPECIFICATIONS
Mechanical Specifications

ANT-20G-50

ANT-20G-90±50 µrad (±10 arc sec)

Resolution

0.25 µrad (0.05 arc sec)

0.25 µrad (0.05 arc sec)

Repeatability (Bi-Directional)(1)±18 µrad (±4 arc-sec)±10 µrad (±2 arc-sec)

Repeatability (Uni-Directional)±5 µrad (±1 arc-sec)±5 µrad (±1 arc-sec)

Tilt Error Motion±90 µrad (±18 arc sec)

±50 µrad (±10 arc sec)
150 degrees per second

Maximum Speed
1200 rad/s2

Maximum Acceleration

500 rad/s2
See graph for typical performance

Settling Time

±0.4 µrad (±0.08 arc sec)

In-Position Stability(2)±0.2 µrad (±0.04 arc sec)

Nominal Radius of Rotation

50 mm

90 mm

Height from Tabletop to Rotation Point

19.1 mm57.5 mm

Maximum Torque (Continuous)

0.40 N-m

0.85 N-m

Load Capacity

ANT-20G Series

20°±90 µrad (±18 arc sec)

Goniometers

20°

Accuracy(1)Rotation Angle

Axial
Moment

1.5 kg

2.0 kg

60 kg-mm

80 kg-mm0.55 kg (1.2 lb)

Stage Mass

1.1 kg (2.4 lb)
AluminumMaterial

30,000 Hours

MTBF (Mean Time Between Failure)

Notes:
1. Certified with each stage.
2. In-Position Jitter listing is 3 sigma value.
• Specifications are per axis, measured at the rotation point. Performance of multi-axis systems is payload and workpoint dependent. Consult factory for multi-axis or non-standard
applications.

Mechanical Specifications

ANT-20G-50

ANT-20G-90

20°

20°

Accuracy(1)±90 µrad (±18 arc sec)

±30 µrad (±6 arc sec)

Resolution

0.25 µrad (0.05 arc sec)

0.25 µrad (0.05 arc sec)

Repeatability (Bi-Directional)(1)±10 µrad (±2 arc-sec)±10 µrad (±2 arc-sec)

Repeatability (Uni-Directional)±5 µrad (±1 arc-sec)±5 µrad (±1 arc-sec)

Tilt Error Motion±40 µrad (±8 arc sec)

±30 µrad (±6 arc sec)

Rotation Angle

150 degrees per second

Maximum Speed
375 rad/s

250 rad/s2

2Maximum Acceleration

See graph for typical performance

Settling Time±0.2 µrad (±0.04 arc sec)

In-Position Stability(2)±0.15 µrad (±0.03 arc sec)

Nominal Radius of Rotation

110 mm

160 mmHeight from Tabletop to Rotation Point

76.2 mm

120.4 mm

Maximum Torque (Continuous)

1.00 N-m

2.40 N-m

Load Capacity

Axial
MomentStage Mass
Material
MTBF (Mean Time Between Failure)

2.0 kg

3.5 kg

80 kg-mm

140 kg-mm

1.2 kg (2.6 lb)

1.6 kg (3.5 lb)
Aluminum
30,000 Hours

Notes:
1. Certified with each stage.
2. In-Position Jitter listing is 3 sigma value.
• Specifications are per axis, measured at the rotation point. Performance of multi-axis systems is payload and workpoint dependent. Consult factory for multi-axis or non-standard
applications.

Note: To ensure the achievement and repeatability of specifications over an extended period of time, environmental temperature must be controlled to within
0.25ºC/24 hours. If this is not possible, alternate products are available. Please consult Aerotech Application Engineering for more information.

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2ANT-20G Series SPECIFICATIONS

ANT-20G Series

Goniometers

Electrical Specifications

ANT-20G-50

ANT-20G-90

ANT-20G-110

ANT-20G-160

Slotless, Brushless, Direct-Drive

Drive System

Noncontact Encoder

Feedback±40 VDC

Maximum Bus Voltage
Limit Switches

5 V, Normally Closed

Home Switch

Near Center

Recommended Controller

ANT-20G-50

ANT-20G-90

A3200

Ensemble

Epaq-MXH
Epaq MR-MXH
Ensemble ML-MXH

Soloist

Soloist ML-MXH

Multi-Axis

Single Axis

ANT-20G-110

Npaq-MXR
Npaq MR-MXH
Ndrive ML-MXH

ANT-20G-160

60

1240

82040020-440-860-1280-16100
1050Position (deg)20.4

Position Error (μrad)← 158 ms Move and Settle

10.2

0010.2

20.4

30.6

40.8

510

100

200

300
400
500
Move Time (ms)

600

0.04
0.03

0.1
0.05

0.02
0.01
00
-0.05

-0.01

-0.1
-0.15

-0.02
-0.03

-0.2

-0.04

-0.25

-0.05
-0.06
12

3Time (s)45

ANT-20G-90 in-position stability. Excellent in-position
stability is another feature of the ANT Series goniometers.

10.0°

0°

10.0°

3.5 arc seconds

3.5 arc seconds

700ANT-20G-90 step and settle performance. Outstanding
settling time enhances throughput of most applications.

3Position Error (arc sec)

31
Step Size: 20°
0.8
Speed: 150 °/sSettle Spec: ±.25 arc sec 0.6

40.2
0.15

0ANT-20G-90 accuracy, five runs, bi-directional, uncalibrated,shows the high level of system accuracy.

50.06
0.05

-0.3

-20
10

50.3
0.25

Position (arc sec)

16Position (µrad)

2080
Accuracy Error (μrad)

100Accuracy Error (arc sec)

Notes:
1. Linear amplifiers are required to achieve the listed specifications. Other options are available.

ANT-20G-90 tilt error motion performance.

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ANT-20G Series DIMENSIONS
ANT-20G-50
Goniometers

U.S. Patent No. 6,442,851
Stage shown at center of travel.
Mounting surface quality: Flatness = 0.005 mm [0.0002 in]

ANT-20G Series

425.8

2.2

1.5

228
4.8

5.8
66

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ANT-20G Series DIMENSIONS
ANT-20G-90
U.S. Patent No. 6,442,851
Stages shown at center of travel.
Mounting surface quality: Flatness = 0.005 mm [0.0002 in]

ANT-20G Series

Goniometers62.2454

2.2

14.4

104.6
101

1.5

41.66

8
4.8

55.8

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ANT-20G Series DIMENSIONS
ANT-20G-50-90
Goniometers

45.5

AGC Series

80

104.6
111.8

U.S. Patent No. 6,442,851
All stages shown at center of travel. Mounting surface quality: Flatness = 5 µm [0.0002 in.]www.aerotech.com

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ANT-20G Series DIMENSIONS
ANT-20G-110
U.S. Patent No. 6,442,851
Stage shown at center of travel.
Mounting surface quality: Flatness = 0.005 mm [0.0002 in]

42.2

104.6
101

120.4

1.5

44.20

8
4.8

5.5
807www.aerotech.com

ANT-20G Series DIMENSIONS
ANT-20G-160
U.S. Patent No. 6,442,851
Stages shown at center of travel.
Mounting surface quality: Flatness = 0.005 mm [0.0002 in]

4120.42

50

80.1
28

2.2

104.6
101

8
4.8

125

1.5

8.5
110
142.8

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ANT-20G Series DIMENSIONSAGC Series

Goniometers

ANT-20G-110-160

5.2

21.5

2.2

104.6

142.8

U.S. Patent No. 6,442,851
All stages shown at center of travel. Mounting surface quality: Flatness = 5 µm [0.0002 in.]9www.aerotech.com

ANT-20G Series ORDERING INFORMATION
Ordering Example
50-M

SeriesRadius of Rotation (mm)Stage Construction Options

Mounting and Grid Pattern

5090
110
160/VAC3/VAC6-M

ANT-20G-50
ANT-20G-90
ANT-20G-110
ANT-20G-160

20 degree travel goniometer with proprietary direct-drive motor technology, 50 mm radius of rotation,
limits, 1 Vpp sinusoidal encoder, 1 meter cable, 25 D connector
20 degree travel goniometer with proprietary direct-drive motor technology, 90 mm radius of rotation,
limits, 1 Vpp sinusoidal encoder, 1 meter cable, 25 D connector
20 degree travel goniometer with proprietary direct-drive motor technology, 110 mm radius of rotation,
limits, 1 Vpp sinusoidal encoder, 1 meter cable, 25 D connector
20 degree travel goniometer with proprietary direct-drive motor technology, 160 mm radius of rotation,
limits, 1 Vpp sinusoidal encoder, 1 meter cable, 25 D connector

ANT-20G Series

Ordering Information

Goniometers

ANT-20G

Stage Construction Options
/VAC3
/VAC6

Vacuum preparation to 10-3 torr
Vacuum preparation to 10-6 torr

Accessories
ALIGNMENT-PA10
ALIGNMENT-PA5

10 arc sec orthogonal
5 arc sec orthogonal

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