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Functional Overview

This chapter provides the overview of the features provided by the SHFSG Instrument. nless explicitly stated otherwise, all contents of the manual apply to both the original SHFSG as well as the SHFSG+. The first section contains the description of the functional diagram and the hardware and software feature list. The next section details the front panel and the back panel of the measurement instrument. The following section provides product selection and ordering support.


The SHFSG+ Instrument consists of several internal units that generate digital signals (light blue color, referred to as Digital Signal Units or DSUs) and several units that transform the digital signals into analog signals with the appropriate center frequency (dark blue color). The front panel is depicted on the left-hand side and the back panel is depicted on the right-hand side. The arrows between the panels and the interface units indicate selected physical connections and the data flow. The SHFSG+ 8.5 GHz Signal Generator comes in a 4-channel and an 8-channel variant, providing either 4 or 8 output channels, respectively. The ordering guide details the available upgrade options for each instrument type and whether the option can be upgraded directly in the field.

Figure 1: SHFSG+ instrument functional diagram

Each channel has signal generation (AWG, Modulation) functionality, as well as common functionality such as the shared communications (32-bit DIO, ZSync). The digital, complex-valued signal from the Digital Signal Unit is up-converted to microwave frequencies in the analog domain using the Signal Output Module.

Super-high-frequency Signal Outputs

  • Low-noise SHF Outputs, DC - 8.5 GHz frequency range, 1 GHz modulation bandwidth
  • Broadband double superheterodyne frequency upconversion
  • Calibrated (Output) Power Range, selectable from -30 dBm to 10 dBm when using the RF path and from -30 dBm to 5 dBm when using the LF path

Advanced Pulse Sequencer

  • Arbitrary Waveform Generator capability
  • Advanced sequencing
    • looping, branching
    • command table
    • advanced trigger control
  • Digital modulation

Hardware Trigger Engine

  • 1 Trigger Engine per Channel
  • 1 Marker Output and Trigger Input per Channel

High-speed Connectivity

  • SMA connectors on front and back panel for triggers, signals and external clock
  • USB 3.0 high-speed host interface
  • Maintenance USB connection
  • LAN/Ethernet 1 Gbit/s controller interface
  • DIO: 32-bit digital input-output port
  • 2 ZSync connectors for clock synchronization and fast data transfer
  • Clock input/output connectors (10 MHz)

Software Features

  • Web-based, high-speed user interface with multi-instrument control
  • Data server with multi-client support
  • LabOne APIs, including Python, QCoDeS and Labber
  • Turnkey software and firmware features for fast system tune-up

Front Panel Tour

The front panel SMA connectors and control LEDs are arranged as shown in Figure 2 and listed in Table 1.

Figure 2: SHFSG+ 8.5 GHz Signal Generator front panel

Table 1: SHFSG+ Signal Generator front panel description
Position Label / Name Description
A Trig TTL Trigger Input
B Mark TTL Marker Output
C Out single-ended waveform Signal Output,
DC-8.5 GHz, max. 10 dBm
D Aux In analog Auxiliary Input, max. 10 V
E multicolor LEDs

Instrument off or uninitialized


all LEDs blink for 5 seconds → indicator used by the Identify Device functionality

  Busy unused
  Ext Ref

External Reference Signal not present/detected


External Reference Signal is present and locked on to


External Reference Signal present, but not locked on to


External Reference Signal present, but lock failed


no connection

  • steady: ZSync fully connected AND synchronized

  • blinking: ZSync synchronized but not yet fully connected


ZSync plugged in, but not connected


ZSync interface error


Instrument off or uninitialized


Instrument is initialized and has no warnings or errors


Instrument has warnings


Instrument has errors

Soft power button

Power button with incorporated status LED


Instrument off and disconnected from mains power

  • flashing rapidly (>1/sec): Firmware is starting

  • flashing slow (<1/sec): Firmware ready, waiting for connection

  • constant: Instrument ready and active connection over USB orEthernet

  • breathing: Instrument off but connected to mains power → safeto power off using the rear panel switch, or restart using the softpower button

  • flashing: Instrument booting up

  • constant: Fatal error occurred

Back Panel Tour

The back panel is the main interface for power, control, service and connectivity to other ZI instruments. Please refer to Figure 3 and for the detailed description of the items.

Figure 3: SHFSG+ Instrument back panel

Table 2: SHFSG+ Instrument back panel description
Position Label / Name Description
Earth ground
4 mm banana jack connector for earth ground, electrically connected to the chassis and the earth pin of the power inlet
B AC 100 - 240 V Power inlet, fuse holder, and power switch
C MDS 1 SMA: bidirectional TTL ports for multi-device synchronization
D MDS 2 SMA: bidirectional TTL ports for multi-device synchronization
E Maintenance Universal Serial Bus (USB) 3.0 port for maintenance and instrument control
F LAN 1GbE 1 Gbit LAN connector for instrument control
G DIO 32bit 32-bit digital input/output (DIO) connector
H USB Universal Serial Bus (USB) 3.0 port connector → do not use for standard operation
I ZSync Secondary Secondary inter-instrument synchronization bus connector
Attention: This is not an Ethernet plug, connection to an Ethernet network might damage the instrument.
J ZSync Primary Primary inter-instrument synchronization bus connector
Attention: This is not an Ethernet plug, connection to an Ethernet network might damage the instrument.
K External Clk In External Reference Clock Input (10 MHz/100 MHz) for synchronization with other instruments
L External Clk Out External Reference Clock Output (10 MHz/100 MHz) for synchronization with other instruments

Ordering Guide

Table 3 provides an overview of the available SHFSG+ products. Upgradeable features are options that can be purchased anytime without the need to send the Instrument back to Zurich Instruments.

Table 3: SHFSG+ Instrument product codes for ordering
Product code Product name Description Field upgrade possible
SHFSG4 SHFSG+ Signal Generator Base 4-channel Super-High-Frequency Signal Generator (SHFSG+) -
SHFSG8 SHFSG+ Signal Generator Base 8-channel Super-High-Frequency Signal Generator (SHFSG+) -
SHFSG-RTR SHFSG Output Router and Adder Option Option for all variants of the SHFSG+ Yes
Table 4: Product selector SHFSG+
Feature SHFSG+
4 channels
8 channels
Number of Output Channels 4 8
Number of analog RF synthesizers 4 4
Digital oscillators per channel 8 8
Mixer-calibration-free analog frequency upconversion
(double super-heterodyne)
yes yes
Frequency range DC-8.5 GHz DC-8.5 GHz
Total number of Markers/Triggers
(1 each per channel)
4/4 8/8
Vertical resolution Output 14 bit 14 bit
Digital IQ modulation yes yes
ZSync capability yes yes
Sequencing yes yes
USB 3.0 yes yes
LAN 1 Gbit/s yes yes
Table 5: Differences between SHFSG and SHFSG+
Description Base instrument Improved phase noise
Improved output noise
Fast output muting functionality
External differences Base instrument Holographic "+" sticker on front panel
Product image
Upgrading from SHFSG to SHFSG+ Contact us to discuss the possibilities for your instruments! -