Performance Tests
Output Standing Wave Ratio (SWR) Test
Agilent E4418B/E4419B Service Guide
2-23
Output Standing Wave Ratio (SWR) Test
Specification
Description
This test measures the standing wave ratio (SWR) of the 50MHz 1mW
output (power ref) connector on the power meter to verify that it is within
its published specification.
When RF power is transferred from a source to a load, the level of power
absorbed by the load, P
A
, is dependent on the respective impedance of the
load and the effective output impedance of the source. This can be
expressed in terms of the voltage reflection coefficients (VRC) as follows:
Equation 2-5: Power Absorbed By The Load
Where:
•
P
ZO
is the power that the source will deliver to a matched load.
•
Γ
S
and
Γ
L
are the VRCs of the source and load respectively.
This method for measuring the source match exploits this relationship by
presenting the source with two different values of
Γ
L
and measuring the
power delivered to the load under the two conditions. The load used is a
Electrical Characteristics
Performance Limits
(maximum)
Output SWR
1.06
1
1.08
2
1. For instruments with the 50MHz 1mW output (power ref) connector
mounted on the front panel.
2. For instruments with the 50MHz 1mW output (power ref) connector
mounted on the rear panel. This applies to models E4418B and E4419B
with option 003 fitted.
P
A
P
ZO
1
Γ
L
2
–
1
Γ
S
Γ
L
–
2
----------------------------
×
=
Where:
4402serv.book Page 23 Tuesday, October 14, 2003 3:18 PM
Summary of Contents for E4418B
Page 19: ...1 Specifications 4402serv book Page 1 Tuesday October 14 2003 3 18 PM ...
Page 37: ...2 Performance Tests 4402serv book Page 1 Tuesday October 14 2003 3 18 PM ...
Page 69: ...3 Adjustments 4402serv book Page 1 Tuesday October 14 2003 3 18 PM ...
Page 81: ...4 Theory of Operation 4402serv book Page 1 Tuesday October 14 2003 3 18 PM ...
Page 95: ...5 Replaceable Parts 4402serv book Page 1 Tuesday October 14 2003 3 18 PM ...
Page 119: ...6 Troubleshooting 4402serv book Page 1 Tuesday October 14 2003 3 18 PM ...