MegiQ VNA04 Series, Руководство пользователя

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VNA0440 – VNA0440e
VNA0460 – VNA0460e
user manual V3.1
- 10 -
www.megiq.com
5. Overview
•
Overview of VNA measurements
•
Block diagram and internal functions
•
The user interface software
Overview of VNA measurements
A VNA measures impedances and gains at high frequencies. Since it measures both the
magnitude and the phase it is called a Vector Network Analyzer.
A measurement typically consists of a sweep over a range
of frequencies and the results are usually frequency
response curves.
One-port measurement
Measurements can be done on one-port devices such as
antennas and circuits. To do this the VNA will transmit a
signal on a port towards the DUT, and at the same time
receives the signal back from that port. From the measured
receive signal the VNA can calculate the impedance
connected to the port.
Two-port measurement
A VNA can also perform measurements on two-port
devices such as amplifiers and filters. In this setup the
VNA will do the impedance measurement on two ports. In
addition, the signal is also sent through the DUT and the
signal is measured at the other port. This is a measurement
of the gain, or loss, of the DUT from one port to the other.
The gain measurement is done in both directions to fully
characterize the DUT.
Multi-port measurement
In multi-port measurements all port impedances are measured and all combinations of
gains between the ports.
The VNA04x0e has an extra generator port that can be used to measure three-port devices
but since this port can not measure the impedance connected to it the three-port
measurement is not fully complete. This can be completed by changing the DUT ports
around.