Signal Hound SM200C User Manual

Understanding the SM-series Hardware | Front End Architecture
16
3.2 Front End Architecture
3.2.1 SM200A/B/C
The SM200 is a low IF receiver. We chose this architecture to complement our low phase noise
local oscillator (LO), while avoiding the shortfalls of zero IF (direct) conversion, and because of
the availability of high linearity direct conversion demodulators and I/Q mixers.
The SM200 contains four mixer bands covering 120 MHz to 20 GHz, and one direct conversion
band covering 100 kHz to 160 MHz A preselector, consisting of 21 sub-octave band pass filters,
covers 20 MHz to 20 GHz. Below 650 MHz, the preselector may be bypassed to increase sweep
speed and improve phase response (shown as high pass and low pass filters rather than band
pass filters), and guarantee 40 MHz of useable bandwidth. With the preselector enabled, as little
as 6 MHz of I/Q data may be available, especially below 100 MHz center frequency.
Four separate mixers, optimized for IP3 and image rejection within their operating range, convert
the incoming RF signal into baseband I/Q signals. In the SM200, the LO is typically injected above
the RF by 15-180 MHz. This generates a baseband I/Q signal, which is filtered and then digitized
at 500 MSPS, and streamed to Intel’s Arria 10 FPGA.

Signal Hound SM200C Specifications

General

Brand	Signal Hound
Model	SM200C
Category	Measuring Instruments
Language	English