About the Frontend Control option
R&S
®
SMW-K553
9
User Manual 1179.4240.02 ─ 02
2
About the Frontend Control option
This chapter provides information on required options and basics for controlling exter-
nal frontends.
2.1
Required options
The equipment layout for external frontend operation includes:
●
Standard or wideband baseband generator (R&S
SMW-B10/-B9)
●
Baseband main module (R&S
SMW-B13/-B13T) or wideband baseband main mod-
ule (R&S
SMW-B13XT)
●
Frequency option:
–
RF A: R&S
SMW-B106/B1006 or higher
–
RF B: R&S
SMW-B206/B2006 or higher
●
Frontend control option R&S
SMW-K553
For more information, see data sheet.
2.2
External frontend basics
Due to the physical dimensions of modern signal generators, long RF cables between
the DUT and the signal generator are often necessary in complex test setups. When
measuring high frequency signals, the long RF cable can lead to unwanted loss.
An external frontend with smaller physical dimensions allows for testing closer to the
DUT. The test signal is transferred (Tx mode) from the R&S
SMW to the external fron-
tend on a lower intermediate frequency (IF). At the external frontend, the IF signal is
upconverted and further transerred to the DUT, for which loss does not have a major
effect.
Thus, the external frontend outsources the conversion of the IF input signal to the RF
output signal required for processing at the DUT. The external frontend upconverts the
low-frequency IF input signal to a higher frequency RF signal using its own internal
local oscillator (LO). For all subsequent signal generation steps in the R&S
SMW, this
process is transparent.
Outsourcing has two main advantages:
●
Extended frequency range:
The external frontend can process RF data in a higher frequency range than the
R&S
SMW itself supports. For example, using an R&S
FE44S external frontend
and R&S
SMW, you can generate RF signals in a range of 24
GHz to 44
GHz.
●
Minimized RF cable loss:
Difficult testing environments, long RF cables between the R&S
SMW and the DUT
are no longer necessary. The external frontend, which is much smaller than the
R&S
SMW, can be placed closer to the DUT using much shorter RF cables. The
External frontend basics
