MegiQ VNA04 Series, User Manual

Page: 11 / 64

VNA0440 – VNA0440e
VNA0460 – VNA0460e
user manual V3.1
www.megiq.com
- 11 -
S-Parameters
The measured DUT characteristics impedance and gain are called Scatter Parameters
or S-Parameters
. They are written as ‘
Sxy
’, where x and y are port numbers. If the port
numbers x and y are the same, an impedance is implied. If the port numbers are different
it represents the gain or loss of a signal
from port y to port x .
These are the S-parameters that the VNA04x0 can measure:
•
S11 : Impedance at port 1
•
S22 : Impedance at port 2
•
S12 : Gain or loss from port 2 to port 1
•
S21 : Gain or loss from port 1 to port 2
The VNA04x0e can also measure these parameters:
•
S13 : Gain or loss from port 3 to port 1
•
S23 : Gain or loss from port 3 to port 2
The impedance S-parameters can be converted to a number of formats such as complex
impedance, return loss, forward loss and SWR. These all represent the impedance.
The Gain S-parameters are usually represented as magnitude and phase. The phase can
also be represented as a
Group Delay which is a dynamic delay characteristic of a multi-
port device.
Block diagram
ADC
ADC
DET
DET ATT
BRIDGE BIAS-T
BRIDGE
BIAS-T
BIAS-T AMP
P1
P2
GEN
CPU USB
GEN
ATT
MegiQ VNA04x0 Block Diagram
FILES