Agilent Technologies Option H48 Multiport Test Set Z5623A - Manual (Page 73)

Agilent Technologies Z5623A Option H48 5 -5
Performance Verification
Test Strategy
Insertion Loss
For this measurement, Port 1 of the network analyzer will be connected
to one of the test ports of the test set, and Port 2 of the network
analyzer will be connected either to the Reflection port or to the
Transmission port of the test set. By definition,
Insertion Loss =
− S
21
where Insertion Loss and S
21
are both in units of dB.
The network analyzer will be configured to measure S
21
. Limit lines
will be set up in such a way that each limit equals the negative of the
corresponding insertion loss test limit shown in
Table 5-2 . For example,
if an insertion loss test limit happens to be 1.0 dB, the corresponding
S
21
limit will be
−1.0 dB.
Insertion loss is a maximum spec. Therefore, each S
21
limit will be set
up as a minimum limit. For example, if an insertion loss test limit
happens to be 1.0 dB, the limit table will be set up so that S
21
must be
above −1.0 dB in order for the instrument to pass. (S
21
will always be
zero or negative because the test set provides no amplification. In units
of dB, S
21
can range from zero to minus infinity.)
Return Loss
For this measurement, Port 1 of the network analyzer will be connected
to one of the test ports of the test set, and Port 2 of the network
analyzer will be connected to the Reflection port of the test set. By
definition,
Return Loss = − S
11
where Return Loss and S
11
are both in units of dB.
The network analyzer will be configured to measure S
11
. Limit lines
will be set up in such a way that each limit equals the negative of the
corresponding return loss test limit shown in
Table 5-2 . For example, if
a return loss test limit happens to be 20 dB, the corresponding S
11
limit
will be −20 dB.
Return loss is a minimum spec. Therefore, each S
11
limit will be set up
as a maximum limit. For example, if a return loss test limit happens to
be 20 dB, the limit table will be set up so that S
11
must be below
−20 dB
in order for the instrument to pass. (S
11
will always be zero or negative
because the test set provides no amplification. In units of dB, S
11
can
range from zero to minus infinity.)