R&S ZVA24, Руководство по обслуживанию

Страница: 318 / 606

Repairs R&S ZVA
1177.5333.02 3.10 E-11
Reflectometer Unit ZVA50
A reflectometer unit comprising a
coupler , a generator section (Driver24 and Doubler50) and a
receiver section (Receiver50) is incorporated in every port (Port1 to 4). The generator and the
receiver are screwed together to form a compact unit.
Coupler Unit
The coupler contains a bias-T and two directional couplers. One coupler is used to separate the signal
going to the DUT from the signal coming from the DUT. The reference signal (= measure of the signal
to the DUT) is obtained from the second coupler. The reference signal provides a reference for relative
measurements.
Driver24
The driver is the same as it is used in ZVA40. Frequency range 6 is extended to 25 GHz.
Range Basic frequency range
from synthesizer
Doubler 1 Frequency Doubler 2 Output frequency
1 10 MHz to 8.0 GHz --- 10 MHz to 8.0 GHz --- 10 MHz to 8.0 GHz
2 4 GHz to 5.05 GHz x 8.0 GHz to 10.1 GHz --- 8.0 GHz to 10.1 GHz
3 5.05 GHz to 6.35 GHz x 10.1 GHz to 12.7 GHz --- 10.1 GHz to 12.7 GHz
4 6.35 GHz to 8.0 GHz x 12.7 GHz to 16.0 GHz --- 12.7 GHz to 16.0 GHz
5 4.0 GHz to 5.0 GHz x 8.0 GHz to 10.0 GHz x 16.0 GHz to 20 GHz
6 5.0 GHz to 6.25 GHz x 10.0 GHz to 12.5 GHz x 20.0 GHz to 25 GHz
Doubler50
The doubler contains a frequency doubler for the range 25 GHz to 50 GHz, a switchable filter unit and a
broadband amplifier for the range 10 MHz to 50 GHz.
Range Frequency range from
driver24
Doubler Output frequency
1 10 MHz to 25.0 GHz --- 10 MHz to 25.0 GHz
2 12.5 GHz to 14.9 GHz x 25.0 GHz to 29.8 GHz
3 14.9 GHz to 18.5 GHz x 29.8 GHz to 37.0 GHz
4 18.5 GHz to 25.0 GHz x 37.0 GHz to 50.0 GHz
Receiver50
The receiver section has two channels (measurement channel and reference channel). The
measurement channel contains a buffer amplifier, two mixers for each of the frequency ranges 10 MHz
to 2.5 GHz and 2.5 GHz to 50 GHz, LO doublers, LO amplifiers and an IF amplifier. The reference
channel is identical to the measurement channel without the buffer amplifier. In the mixers, the input
signal is directly converted to the IF range, approx. 15 to 21 MHz. In the frequency range 10 MHz to 24
GHz the mixers are used as basic wave mixers (IF = LO
– RF). In the range 24 GHz to 50 GHz the
mixer for the upper frequency range works as a harmonic mixer (IF = 3LO
– RF).