QCM-RF II#
Description#
The QCM-RF II is an RF signal generator designed to control quantum devices using parameterized pulses. This module, which supersedes the QCM-RF, provides the same wave generation functionalities but with a flatter and cleaner spectrum.The QCM-RF II achieves a 70 dBc SFDR across its full range of 2 to 18.5 GHz. You can find the specifications table for the QCM-RF II at Specifications. Each module is equipped with two SMA female connectors for signal output and two SMP male connectors for marker outputs.The operational status of the QCM-RF II is continuously monitored by four LED lights. The front of a QCM-RF II module is presented below:
On the front of the QCM-RF II module one can find the following components:
2 x SMA female (receptacle) connectors: 2 outputs (O[1-2] @ 50 Ω).
2 x SMP male (pin) connectors: Marker output channels (M[1-2] 0-3.3 V TTL).
4 x status LEDs: See section Frontpanel LEDs for details.
The O[1-2] channels of the QCM-RF II output signals over the frequency range of 2 to 18.5 GHz. The module incorporates 6 multiplexed sequence processors which span a 500 MHz bandwidth. Each independently operated output channel has its own local oscillator to facilitate internal upconversion.
The module creates signals parametrized by variables such as gain, offset, NCO frequency and phase, etc., and also by waveform envelopes stored in memory.
This parametrization is controlled by the AWG paths of the Q1 sequencer, which have two waveform paths each (hereon referred to as path 0 and 1).
The outputs of the AWG paths are mixed with the NCO by the onboard IQ mixers, enabling operation as modulated IQ signals.
These paths, after mixing with the LO, can be connected to any output of the instrument (i.e. O1 and O2).
The sequencers also control two marker output channels.
The RF upconversion stage features two independent IQ mixers on-board for generating the output signals in the range of 2-18.5GHz.
For a list of available features please see Detailed features:.
Note
For cables connected to the module, a maximum length of 30 meters is allowed.
Block Diagram#
Detailed features:#
1. 10MHz Reference#
Alongside all modules available, the QCM-RF II module operates with respect to a 10MHz reference provided by the cluster.
2. Trigger#
The trigger of the QCM-RF II is connected to the cluster and allows for fast synchronization between modules.
3. SYNQ#
The Qblox SYNQ technology enables simple and quick synchronization over multiple instruments, allowing for modules to be started synchronously within << 1ns. See section synchronization for more information.
4. LINQ#
The Qblox LINQ technology allows for the results of measurements to be shared between devices, distributing outcomes in < 364 ns.
5. Q1 Sequence Processor#
The Q1 sequencers are the heart(s) of the QCM-RF instrument. They orchestrate the experiment using a custom low-latency sequence processor specifically designed for quantum experiments. Each QCM-RF has 6 control sequencers to target multiple frequencies with one output.
Each control sequencer has a dedicated AWG path, which enables parametrized pulse generation and readout.
6. Marker output channels#
Each sequencer has control over the two marker output channels, with the
control of each sequencer being OR’ed to create the final marker outputs.
The markers can be dynamically controlled with the set_mrk instruction of the
sequence processor (see section on latched instructions),
but can also be overwritten with the static marker overwrite parameters
ControlSequencer.marker_ovr_en() and ControlSequencer.marker_ovr_value().
The marker output range is 0-3.3 V TTL. In the QCM-RF II module set_mrk is also used
to toggle the switches before the outputs to enable the respective
output.
For the QCM-RF II module, bit indices 0 & 1 correspond to output enable 1 and 2 respectively,
indices 2 & 3 correspond to marker outputs 2 and 1 respectively.
6.1 Setting Markers as Active HIGH/LOW#
The default state of marker is active high (OFF = 0V, ON = 3.3V). Users
have the ability to change the marker output from active HIGH to active LOW ( OFF = 3.3 V, ON = 0V). It can be done
using the parameter QCM_RF.marker0_inv_en(). This inversion of marker default states is possible for all marker
channels. Here marker0 and marker1 correspond to bit indices 3 & 2 respectively in the argument of
set_mrk as mentioned above.
7. Sequencer multiplexer#
Each of the 6 control sequencers in a QCM-RF has one complex output stream. This can either be connected to or disconnected from the output using the channel map.
ControlSequencer.connect_out0()connects a sequencer output stream to an output. For example, to connect the IQ path of sequencer 2 to output 1, useqrm.sequencer2.connect_out1("IQ"). The argument may be “IQ” (True) or “off” (False). All the output streams that are connected to the channel map are added together. This may result in clipping.
For more details about multiplexing and its operation on our cluster, please refer to the multiplexed sequencing tutorial.
Note
The default state is that the output stream of even (odd) sequencers is connected to output0 (output1). This is so that the modules can always play a sequence in their default state.
The channel map may be cleared by setting all connect_out* parameters for all sequencers to ‘off’. The QCM_RF.disconnect_outputs() convenience function may be used instead.
8. Digital Offset#
Each sequencer has a dedicated offset step for both path 0 and 1, which can be
statically configured using the ControlSequencer.offset_awg_path0() parameters.
However, the offset can also be dynamically controlled using the set_awg_offs
instruction of the sequence processor which enables pulse parametrization.
(see section on latched instructions). The static and
dynamic offset controls are complementary.
Note
This offset is applied to the signals before the mixer and cannot be used for DC offset correction if the mixer is enabled.
9. DAC#
The dynamic output range of the QCM-RF’s DACs is 1 Vpp and 50 Ω terminated at 1GBps.
10. Offset DAC#
The offset DAC allows users to apply a DC offset to the output signal without the risk of clipping the signal at the DAC.
11. Local Oscillator#
The QCM-RF II module comes equipped with built-in independent local oscillators for each output capable of generating signals between 2.5 and 18GHz for IQ mixing.
12. IQ Mixer#
The QCM-RF II module also has onboard IQ mixers for the output. The LO’s of these internal mixing stages are capable
of sweeping between 2-18.5GHz. This allows for the generation of signals at the qubit frequency.
13. Variable Attenuator#
The QCM-RF II module has variable attenuators on both the output terminals. These attenuators can be programmed from 0 to 30dB in 2dB increments. Note the difference in range from the QCM-RF (see Specifications).
14. Output Switch#
The output terminal of the QCM-RF II can be toggled with an inbuilt switch, which can also be controlled dynamically with the Q1 processor.
Specifications#
Quantity |
Value |
|---|---|
Frequency range |
2 - 18.5 GHz |
Analog output channels |
2 |
Analog bandwidth |
(-3 dB) 500 MHz, (-6 dB) 650 MHz, (-9 dB) 720 MHz |
Pulse Processing Units |
6 Q1 sequence processors |
DAC sample rate |
1 GS/s (for I and Q) |
DAC resolution (vertical) |
16 bit (for I and Q) |
Binary output markers |
2 (0-3.3 V LVTTL) |
Maximum output power (into 50 Ohm) |
+10 dBm (< 8 GHz), +5 dBm (> 8 GHz) |
Attenuation range |
0-30 dB in 2 dB steps |
Output harmonic levels |
> 35 dBc |
SFDR within 2 - 18.5 GHz full range (including LO leakage, spurious sidebands, excluding output harmonics) |
> 54 dBc at 100%, > 64 dBc at 50%, > 70 dBc at 25% IF amplitude |
Phase noise (@3 GHz, 10 kHz offset) |
-115 dBc/Hz |
Frequency resolution |
0.25 Hz (IF), 1 Hz (LO) |
Output switch signal suppression |
> 60 dB |
Output coupling |
AC coupled |
Output impedance |
50Ω |
Driver/API |
SCPI / Python / QCoDeS |
Max. power consumption (via Cluster) |
48 W |
Input/Output connector type |
SMA |
Marker connector type |
SMP |
Dimensions single module |
269 x 130 x 20 mm³ |
Weight |
0.438 kg |
Quantity |
Value |
|---|---|
Frequency range |
2 - 18.5 GHz |
Analog output channels |
2 |
Analog bandwidth (-3dB) |
750 MHz |
Pulse Processing Units |
6 Q1 sequence processors |
DAC sample rate |
1 GS/s (for I and Q) |
DAC resolution (vertical) |
16 bit (for I and Q) |
Binary output markers |
2 (0-3.3V LVTTL) |
Maximum Output power (into 50 Ohm) |
+5 dBm |
Attenuation range |
0-60 dB in 2 dB steps |
Spurious-free dynamic range (within analog bandwidth) |
> 50 dB |
Phase noise (@3 GHz, 10 kHz offset) |
-115 dBc/Hz |
Frequency resolution |
0.25 Hz (IF), 1 Hz (LO) |
Output switch signal suppression |
> 60 dB |
Output coupling |
AC coupled |
Output impedance |
50Ω |
Driver/API |
SCPI / Python / QCoDeS |
Max. power consumption (via Cluster) |
48 W |
Input/Output connector type |
SMA |
Marker connector type |
SMP |
Dimensions single module |
269 x 130 x 20 mm³ |
Weight |
0.303 kg |
Power Consumption |
39W |