Anritsu 63NF50 Operations Guide

OPERATION AND MAINTENANCE MANUAL

FOR SWR AUTOTESTERS AND BRIDGES

1. INTRODUCTION

This manual provides product descriptions and
specifications for WILTRON Series 59, 63, and 97
SWR Autotesters and Series 58, 60, 62, and 87 SWR
Bridges. It also includes procedures for measuring
the directivity of these components.

2. GENERAL DESCRIPTION

The SWR Autotesters and bridges (Figure 1) are
broadband microwave measurement instruments.
They are used with other test instruments for mak­ing fixed-- and swept--frequency return loss (SWR)
measurements over a wide range of radio frequen­cies. Return loss measurements are made to check
the performance of systems, subsystems, and micro­wave components such as amplifiers, directional

couplers, attenuators, filters, splitters, and termina­tions.

The WILTRON SWR Autotesters and bridges are
precision--balanced Wheatstone bridges. Except for
the two 4--port comparison--type instruments (Mod­els 59A50 and 58A50) that use an offset termination
in the reference arm, every model has an internal
precision reference termination included in one arm
of its bridge. The major difference between the SWR
Autotester and the SWR bridge is that the SWR Au­totester contains a built--in RF detector.

3. PERFORMANCE SPECIFICATIONS

Performance specifications for SWR Autotesters are
listed in Table 1; specifications for SWR bridges are
listed in Table 2.

Figure 1. Typical WILTRON SWR Autotester and SWR Bridge

490 JARVIS DRIVElMORGAN HILL, CA 95037-2809

P/N: 10100-00008

REVISION : M

PRINTED: NOVEMBER 1994

COPYRIGHT 1983 WILTRON CO.

Table 1. SWR Autotester Performance Specifications

Models

Directivity

(dB)

Accuracy➀

Input Z
(ohms)

Test Port

Connector

59 Series Comparison SWR Autotester, 10 MHz to 18 GHz

59A50 36

0.01–8 GHz:
8–18 GHz:

0.016 ±0.06ρ2 ➁➂

0.01 6 ±0.1ρ

2

50 GPC–7

63 Series SWR Autotesters, 10 MHz to 4 GHz

63A50
63N50 Type N Male

40➃

0.01 ±0.06ρ

2

50

GPC7

63NF50 Type N Female

97 Series SWR Autotesters, 10 MHz to 18GHz

0.01–8 GHz 8–18 GHz

97A50 36

97A50-1 40

0.016 ±0.06ρ

0.01 ±0.06ρ

2

0.016 ±0.1ρ

2

0.01 ±0.1ρ

2

2

GPC–7

Physical

Dimensions:

7.6 x 5.1 x 2.8 cm
(3 x 2 x 1

1

⁄8 in.)

plus connectors

Weight:

340 g (12 oz)

Dimensions:

6.7 x 5.1 x 2. 54 cm

5

⁄8 x 2 x 1 in.)

(2
plus connectors

Weight:

340 g (12 oz)

97S50

35

0.018 ±0.08ρ

97SF50 WSMA Female

97S50-1

38

0.013 ±0.08ρ

2

0.018 ±0.12ρ

2

0.013 ±0.12ρ

2

50

2

97SF50-1 WSMA Female

97N50

35

0.018 ±0.08ρ

2

0.018 ±0.12ρ

2

WSMA Male

WSMA Male

Type N Male

Dimensions:

7.6 x 5.1 x 2.8 cm

1

(3 x 2 x 1

⁄8 in.)

plus connectors

Weight:

340 g (12 oz)

97NF50 Type N Female

97N50-1

38

0.013 ±0.08ρ

2

0.013 ±0.12ρ

2

Type N Male

97NF50-1 Type N Female

All Models
Insertion Loss (from input to test port): 6.5 dB nominal

Detector Output Polarity: Negative
Output Time Constant: 2 µs
Maximum Power Input: 0.5 watts (+27 dBm)
Input Connector: Type N Female
Detector Output Connector: BNC Female

➀ Where ρ is the refle cti on coe fficie nt bein g mea sured . Ac curacy includes the effects of test port reflections and directivity.
➁ When used with 28A50-1 Precision Termination. The effective di rectivity of the SWR Autotester can be increased to 60 dB by using the

Ripple Extraction return lo ss measure men t technique with the 18A50 Air Line and 29A50 -20 Offset Termination.

➂ See parag rap h 4 fo r exp lana tion of accu racy and other terms.
➃ 46 dB directivity available as Option 1. Option 1 accuracy: 0.005 ±0.06 ρ2.

2 SWR OMM

Table 2. SWR Bridge Performance Specifications

Models

Directivity

(dB)

Accuracy➀

Input Z
(ohms)

Test Port

Connector

58 Series Comparison SWR Bridge, 2 to 18 GHz

2–3 GHz:

58A50 35

4–18 GHz:

0.018 ±0.32ρ2 ➁ ➂

3–4 GHz:

0.018 ±0.2ρ

0.018 ±0.13ρ2

2

50 GPC–7

60 Series SWR Bridges, 5 MHz to 2 GHz

60A50
60N50 Type N Male

40➃

0.01 ±0.09ρ

2

50

GPC–7

60NF50 Type N Female

62 Series SWR Bridges, 10 MHz to 1GHz

62N75➄

62NF75 75 Type N Female

40

0.01 ±0.12ρ

2

75 Type N Male

62B75 75 BNC Male

62BF75 75 BNC Female

87 Series SWR Bridges, 2 to 18 GHz

87A50

87A50-1

35

38

2–3 GHz:

3–4 GHz:

4–18 GHz:

2–3 GHz:

3–4 GHz:

4–18 GHz:

0.018 ±0.32ρ

0.018 ±0.2ρ

0.018 ±0.13ρ2

0.013 ±0.32ρ

0.013 ±0.2ρ

0.013 ±0.13ρ2

2

2

2

2

50 GPC–7

Physical

Dimensions:

6.7 x 5.1 x 2.2 cm

5

⁄8 x 2 x 7⁄8 in.) plus connectors

(2

Weight:

340 g (12 Oz)

Dimensions:

6.7 x 5.1 x 2. 54 cm

5

⁄8 x 2 x 1 in.) plus connectors

(2

Weight:

340 g (12 oz)

Dimensions:

6.7 x 5.1 x 2. 54 cm

5

(2

⁄8 x 2 x 1 in.) plus connectors

Weight:

170 g (6 Oz)

Dimensions:

7.3 x 5.1 x 2. 86 cm

5

⁄8 x 2 x 1 1⁄8 in.) plus connectors

(2

Weight:

340 g (12 Oz)

All Models
Insertion Loss (from input to test port): 6.5 dB nominal

Maximum Power Input: 0.5 watts (+27 dBm)
Input Connector: Type N Female, stainless steel, except 67B and 67F Series that have BNC Female

➀ Where ρ is the reflection coefficient being measure d. Accuracy includes the effects of test port reflections and directivity.
➁ When used with 28A50-1 Precision Termination. The effective dire ctivity of the bridge can be increased to 60 dB by using the Ripple

Extraction re turn lo ss measu remen t techniqu e with the 18A5 0 Air Line and 29 A50-20 Offset Termination.

➂ See pa ragrap h 4 fo r exp lana tion of ac curacy and other terms.
➃ 46 dB directivity available as Option 1. Option 1 accuracy: 0.005 ±0.09 ρ2.
➄ 75Ω Type N Female connectors will with stand oc casional mating with 50Ω connectors with ou t damage.

SWR OMM 3

4. EXPLANATION OF SWR

REFERENCE

PLANE

MALE

PIN

DEPTH

(INCHES)

REFERENCE

PLANE

FEMALE

PIN

DEPTH

(INCHES)

0

1

2

3

4

5

1

2

3

4

2

11

2

AUTOTESTER AND BRIDGE
SPECIFICATIONS

Certain key specification terms are explained below.
a. Accuracy. This three-element term defines

the accuracy with which an SWR Autotester or
bridge can make a reflected signal measure­ment. The three elements (

0.01 ±0.06 ρ2) are

described below.
1st Element: (0.01) is the directivity of the SWR

Autotester or bridge expressed as a reflection
coefficient (40 dB for this example, see Table 6).

2nd and 3rd Elements: ±0.06ρ

2

is the deprecia­tion in accuracy due to test port mismatch (im­pedance discontinuity). Element 2 (0.06) is the
inherent test port mismatch expressed as a re­flection coefficient. The 3rd element, rho (ρ), is
the reflection coefficient of the device under test
(DUT). The entire expression describes the
measurement uncertainty caused by the re­flected signal being re-reflected by the test port
mismatch.

a. Beware of Destructive Pin Depth on Mating

Connectors. Before mating, measure the pin

depth (Figure 2) of the device that will mate with
the SWR Autotester or bridge, using a WILTRON
Pin Depth Gauge (Figure 3) or equivalent. Based
on SWR Autotesters and bridges returned for
repair, destructive pin depth of mating connec­tors is the major cause of failure in the field. (A
destructive pin depth has a center pin that is too
long in respect to the connector’s reference
plane.) When the SWR Autotester or bridge is
mated with a connector having a destructive pin
depth, damage will likely occur to the SWR
Autotester or bridge.

b. Directivity. A figure of merit expressed in dB.

This figure represents the ratio of the power
levels as seen at the output port when (1) the
test port signal is fully reflected, and (2) the test
port is perfectly terminated.

c. Frequency Sensitivity. The maximum varia-

tion in output power/voltage that can be ex­pected due to a change in frequency over the
specified range when the input power is held
constant

d. Output Time Constant. The amount of time

required for the selected output pulse to either
rise from the 10% to the 90% point or fall from
the 90% to the 10% point on the waveform.

5. PRECAUTIONS

The SWR Autotesters and bridges are high-quality,
precision laboratory instruments and should receive
the same care and respect afforded such instru­ments. Complying with the following precautions
will guarantee longer component life and less equip­ment downtime due to connector failure. Also, such
compliance will ensure that SWR Autotester or
bridge failures are not due to misuse or abuse—two
failure modes not covered under the WILTRON war-
ranty.

Figure 2. N Connector Pin Depth Definition

Figure 3. Pin Depth Gauge

The center pin of SWR Autotester or bridge con­nectors has a precision tolerance measured in
mils (1/1000 inch). Connectors on test devices
that mate with SWR Autotesters and bridges
may not be precision types and may not have the
proper depth. They must be measured before
mating to ensure suitability. When gauging pin

4 SWR OMM

depth, if the SWR Autotester or bridge connector

Impe da n ce
Connector Type (Te st Port

Connector on Bridg es and
SWR Autotesters

Impe da n ce

measures out of tolerance (Table 3) in the “+”
region of the gauge (Figure 3), the center pin is
too long. Mating under this condition will likely
damage the SWR Autotester or bridge connector.
On the other hand, if the test device connector
measures out of tolerance in the “–” region, the
center pin is too short. While this will not cause
any damage, it will result in a poor connection
and a consequent degradation in performance.

b. Avoid Over Torquing Connectors. Over

torquing connectors is destructive; it may dam­age the connector center pin. Finger-tight is usu­ally sufficient, especially on Type N connectors.
Should it be necessary to use a wrench to tighten
SMA or WSMA connectors, use a torque wrench
that breaks at 5 inch-pounds. As a general rule,

never use pliers to tighten connectors.

c. Do Not Disturb Teflon Tuning Washers On

Connector Center Pins. The center conduc-

tor on many SWR Autotester or bridge connec­tors contains a small teflon tuning washer lo­cated near the point of mating (interface) (Figure

4). This washer compensates for minor imped­ance discontinuities at the interface. The
washer’s location is critical to the SWR
Autotester or bridge’s performance. Do not dis-

turb it.

TEFLON WASHER

Table 3. Pin-Depth Tolerance, SWR
Autotesters and Bridges

Series

58, 59 ,
87,

1

97

58, 59,

87, 97

97 TEST – N 207 –0. 000

60, 63 INPUT – NF 207 +0.000

60 OUTPUT – NF

60, 63 TEST – A +0.000

62 INPUT – NF 207 +0.000

62 TEST – N 207 –0. 000

Port/

Conn. Type

INPUT – NF 207 +0.000

OUTPUT – NF 207 +0.000

TEST – A +0.000

TEST – NF 207 +0.000

TEST – S

TEST – SF

TEST – N 207 +0.000

TEST – NF 207 +0.000

OUTPUT – NF

TEST – NF 207 +0.000

2

2

Pin Depth

(MILS)

–0.010

–0.010

–0.003

+0.003

–0.003

–0.0025
–0.0035

–0.0003
–0.0007

–0.020

–0.003

+0.003

–0.003

–0.020

+0.018

–0.018

Legends and Notes

Typical Model Number:

Gauge

Reading

Same As

Pin Depth

207 +0.000

–0.003

Same As

Pin Depth

N/A

Same As

Pin Depth

207 +0.000

–0.003

Same As

Pin Depth

207 +0.000

–0.018

Same As

Pin Depth

The teflon washer is shown on a GPC-7 connec­tor. A similar washer may be installed on any
WILTRON precision connectors.

Figure 4. Tuning Washer on GPC-7 Connector

SWR OMM 5

97SF50

NOTE

Connector Type Abbreviations:

N = Type N male
NF = Type N female
A = GPC-7