60 GHz RF signal goes via a band-pass filter to the
output connector of the SQM.
From the SQM, the 40 to 60 GHz RF output signal
goes to input connector J1 of the forward coupler,
P/N C27184. The other input to the forward coupler
at connector J2 is the 0.01 to 40 GHz (0.5 to 40 GHz
for 682X5B/683X5B models) RF output signals from
the SDM. From forward coupler output connector
J3, the 0.01 to 60 GHz (0.5 to 60 GHz for the
682X5B/683X5B models) RF output signals go to the
directional coupler.
65 GHz Models (SQM P/N 60-142)
During CW or swept frequency operations in the 40
to 65 GHz frequency range, the 10 to 16.25 GHz RF
signal input is quadrupled and amplified, then goes
to the modulator.The modulator provides for power
level control and amplitude modulation of the RF
output signal. From the modulator,the 40 to
65 GHz RF signal goes via a band-pass filter to the
output connector of the SQM.
From the SQM, the 40 to 65 GHz RF output signal
goes to input connector J1 of the forward coupler,
P/N C27184. The other input to the forward coupler
at connector J2 is the 0.01 to 40 GHz (0.5 to 40 GHz
for 682X5B/683X5B models) RF output signals from
the SDM. From forward coupler output connector
J3, the 0.01 to 65 GHz (0.5 to 65 GHz for the
682X5B/683X5B models) RF output signals go to the
directional coupler.
Power Level
Detection/
ALC Loop
The RF signal output from either the switched filter
assembly (£20 GHz models), the SDM (£26.5 GHz or
£40 GHz models), or forward coupler (>40 GHz mod-
els) goes to the directional coupler for transfer to the
RF OUTPUT connector.A portion of the RF output
signal is detected, amplified, and coupled out as
feedback to the ALC circuitry on the A10 ALC PCB.
In these circuits, the signal from the detector is
summed with the reference voltage that represents
the desired RF output power level. The resulting
voltage is fed from the A10 ALC PCB to the ALC
modulator driver circuit on the A9 PIN Control PCB
(and the ALC modulator driver circuit on the A14
SDM, SQM Driver PCB for >40 GHz models). The
resulting modulator control signals go to the modu-
lators in the switched filter assembly,the SQM (for
>40 GHz models), and the digital down converter
2-30 682XXB/683XXB MM
FUNCTIONAL RF DECK
DESCRIPTION ASSEMBLIES