Specifications
12
Page 23
安捷倫科技高頻元件量測研討會
Feb.23, 2006
Test port 1 Test port 2
C
D
B
A
Test port 3
Test port 4
R
Single Reference Receiver VNAs (like 4-Port PNA-L)
Reference receiver is prior to port switch
Switch corrections cannot be directly measured
TRL* ignores switch correction terms by setting them to zero
1
22
22
11
21
22
12
11
11
2221
1211
10
01
−
•
≅
a
b
a
b
a
b
a
b
SS
SS
TRL* sets switch correction to zero
Page 24
安捷倫科技高頻元件量測研討會
Feb.23, 2006
Alternative to Measuring Switch Corrections
Instead of ignoring the switching terms, we can characterize the
match differences and then apply them during the TRL cal
To do so, we can restate the switch correction terms:
G
f
and G
r
are “delta-match” terms, and they
can be derived from an SOLT calibration
1
11
21
22
12
1
21
21
11
21
12
12
22
12
1
11
21
22
12
1
1
1
1
1
1
−−−
Γ
Γ
=
=
f
r
a
b
a
b
b
a
a
b
b
a
a
b
a
a
a
a
Thru
SHORT
OPEN
LOAD
SHORT
OPEN
LOAD