VNA0440
–
VNA0440e
VNA0460
–
VNA0460e
user manual V3.1
- 51 -
item of the context menu to copy this match to other graphs of the same parameter
(in this case S22).
The resulting antenna implementation has a very nice return loss of about -14dB
throughout the Wifi band.
You can use the
Run
sweep button to run continuous sweeps and the matched results will
be updated with each measurement. This mode can be used to evaluate the matched
impedance when the environment of the antenna changes with a cabinet or hand effects.
When the calibration of this measurement was done carefully and
close to the matching
point, the circuit can often be built on the DUT and the matched results then closely match
the simulation. In some cases an iteration of the matching procedure may be required to
optimize the circuit implementation.
We have modified the labelling of the matching circuit for clarity.
Zm
on the left side is the
Measured impedance
that needs to be
matched and
VNA
on the right side is the (normally)
50 Ohm side
.
Center 2,20GHz / Span 3,60GHz
S22
Z
M-Z
400
1120
1840
2560
3280
4000
400
1120
1840
2560
3280
4000
1
1
1> 2,440GHz: 27,70 - j26,35
1> 2,440GHz: 38,96 - j11,23
3,03nH
1,56pF
Zi
Zo
match at
2,44GHz
2,02 2,11 2,20 2,29 2,38 2,47 2,56 2,65
2,92
F [GHz]
-30
-20
-10
0
RL
[dB]
Center 2,47GHz / Span 0,90GHz
S22
RL
M-RL
1
2
1
2
1> 2,400GHz: -9,32dB
2> 2,500GHz: -5,25dB
1> 2,400GHz: -14,60dB
2> 2,500GHz: -13,73dB
3,03nH
1,56pF
Zi
Zo
match at
2,44GHz
Impedance
Return Loss
VSB Measurements\VSB 44/45: Antennas
14-9-2014 15:37:38
