External Module Control

The EXTERNAL MODULE CTRL dialog box controls the configuration of attached broadband modules and systems.

For Modular Broadband (Modular BB), an MS4647B VNA with Option 8x is required with a connected 3739C Broadband/mmWave Test Set and MA25x00A or 3743x mmWave Modules.

For Standard BB, an MS464xB Series VNA is required with a connected 3738A Broadband/mmWave Test Set and related modules and signal generators.

Figure: EXTERNAL MODULE CTRL Dialog Box Variants – OFF, mmWave 3738, and mmWave 3739 shows the EXTERNAL MODULE CTRL dialog box variants for OFF, mmWave 3738, and mmWave 3739.

Figure: EXTERNAL MODULE CTRL Dialog Box – Broadband shows the variants for Broadband to 220 GHz, 145 GHz, and 125 GHz; and 54 GHz to 220 GHz and 145 GHz.

Figure: EXTERNAL MODULE CTRL Dialog Box – E-Band, and W-Band shows the variants for E-Band 56 GHz to 95 GHz and W-Band 65 GHz to 110 GHz.

Figure: EXTERNAL MODULE CTRL Dialog Box with Broadband to 110 GHz selected (1 of 2) shows the dialog box for systems with Option 84, 85, 86, 87, 88, or 89. These selections are 110 GHz, E-Band 56 GHz to 95 GHz, and W-Band 65 GHz to 110 GHz

External mmWave or broadband test sets are not being used. The dialog in this state is shown in Figure: EXTERNAL MODULE CTRL Dialog Box – Set for OFF below. The 3739 test set does not require external synthesizers so these non-OFF choices will always be available assuming Option 8x is present. The 3738 test set does not require additional options but does require the presence of external synthesizers 1 and 2 on the GPIB bus.

The 3738X Test set is being used with conventional OEM mmWave modules (the ME7828 family of systems). In this case, a check box will be available per-defined band to allow activation of the test set in that band. This option is only available if External Sources 1 and 2 are connected and active. There are no other parameters to select other than to activate or de-activate on a band-by-band basis.

As an example to show how this selection might be used, consider a DUT that is a downconverter taking 250 to 300 GHz down to a fixed IF of 1 GHz. The LO is sub-harmonically driven with an effective multiplier of 18 and will be driven from External Source 3 (EXT. SRC 3). The RF is supplied by an external mmWave module (WR-03 waveguide in this case) which also has an effective source multiplier of 18 and this will be driven from EXT. SRC. 1. This external module also has an LO input (x20 effective multiplier) that will be driven from EXT SRC 2. It is desired to measure both return loss (at the RF) of the DUT as well as its conversion loss. This will require two different multiple source setups since the conversion paths in the VNA are different. The example measurement is described below:

Connect all external synthesizers and make sure the GPIB addresses match and 10 MHz clocks are synchronized (or higher frequency references if those are being used). It is desired that the DUT LO port be driven since that can affect return loss. Since the IF outputs of the mmWave module will be used (and routed to the VNA rear panel), the Ext Module Ctrl for BB/mmWave must be enabled.

In this case, Ext Module Ctrl must be OFF since we will not be using the rear panel IFs. Note that this also disables the test set, so some care is required with RF signal cabling.

The mmWave (3739) selection also assumes the use of OEM mmWave modules but with the 3739 Test Set. Details on some applicable modules, from a hardware perspective, are discussed below and in Multiple Source. Any multiplied transceivers can be used here as long as the frequency and power plans are consistent with the VectorStar system with the 3739X test set. The Test Set offers additional power control options and assumes the use of the internal VNA sources so there are some additional selection options as suggested by Figure: EXTERNAL MODULE CTRL Dialog Box – Set for mmWave (3739) below.

The selection choices per band are described below:

This right side of the radio button array is for the broadband operation (with the 3739x test set and the MA25300A, MA25400A, and 3743x modules) and for banded operation (using the 3739x test set and the 3743x or 3744x modules). The selection for BB/mmWave is straightforward. When checked in a given band, the test set will be activated, the VNA internal transfer switch will be shut down, and the rear panel IF ports on the VNA will be activated.

There are seven choices for use with the MA25300A, MA25400A, 3743X, and 3744X modular heads:

The distinction between these selections is based on the imposed frequency range limits when activated.

Otherwise the selections and instrument operation are the same. The dialog in the case of broadband set for two bands is shown in Figure: EXTERNAL MODULE CTRL Dialog Box – Set for Broadband to 145 GHz.

The MA25300A, MA25400A, 3743x and 3744x modules have independent source and receiver paths that can be selected from the dialog. The selections can be interpreted as follows:

Use the receiver in the remote modules above the receiver breakpoint (30 GHz). Above this breakpoint, the VNA system LO will be set appropriately in terms of frequency and power, the test set configured, and the VNA rear panel IFs will be activated.

Use the source multipliers in the remote modules above the source breakpoints (54 GHz). Above the first breakpoint, the VNA synthesizers will be set appropriately, the test set configured as needed, and ALC leveling prepared (see below). Note that the above and below 54 GHz power control setting apply when this source feature is enabled (more details earlier in this chapter).

This enables a fixed delay at the beginning of the band. This could be useful for certain slow settling DUT measurements or for very low power levels.

The default operation of the 3739-based modes (when not in multiple source) is to use IF leveling in order to get wide power ranges but if the source and receiver frequencies are not close enough (or the receiver is not enabled), then an IF is not available for leveling. The leveling defaults to RF in multiple source 3739-based modes with broadband/mmWave and this is recommended unless one knows the IF will be available (up to about 100 MHz) in the module for leveling. Separate ALC calibrations are available for RF and IF leveling and the system will automatically index the correct calibration table.

This right side of the radio button array is for the broadband operation (with the 3739X test set and 3743X modules), and for banded operation (using the 3739X test set and the 3743X or 3744X modules). The selection for BB/mmWave is straightforward. When checked in a given band, the test set will be activated, the VNA internal transfer switch will be shut down, and the rear panel IF ports on the VNA will be activated.

There are three choices for use with the 3743X and 3744X modular heads:

The distinction between these selections is based on the imposed frequency range limits when activated.

These 3743x and 3744x modules have independent source and receiver paths that can be selected from the above dialog. The selections can be interpreted as follows:

Use the receiver in the remote modules above the receiver breakpoint (30 GHz). Above this breakpoint, the VNA system LO will be set appropriately in terms of frequency and power, the test set configured, and the VNA rear panel IFs will be activated.

Use the source multipliers in the remote modules above the source breakpoints (54 GHz). Above the first breakpoint, the VNA synthesizers will be set appropriately, the test set configured as needed, and ALC leveling prepared (see below). Note that the above and below 54 GHz power control setting apply when this source feature is enabled (more details in Chapter 16).

This enables a fixed delay at the beginning of the band. This could be useful for certain slow settling DUT measurements or for very low power levels.

The default operation of the 3739-based modes (when not in multiple source) is to use IF leveling in order to get wide power ranges but if the source and receiver frequencies are not close enough (or the receiver is not enabled), then an IF is not available for leveling. The leveling defaults to RF in multiple source 3739-based modes with broadband/mmWave and this is recommended unless one knows the IF will be available (up to about 100 MHz) in the module for leveling. Separate ALC calibrations are available for RF and IF leveling and the system will automatically index the correct calibration table.

When any of the five choices under BB/mmWave [3739] are selected and there is a valid VNA leveling cal in effect, the selections for VNA leveling the sub-choices (highlighted below) will be visible. For all other cases, it will not be visible. Note that the leveling sub choices is per-channel but the source leveling is per-band. See Figure: EXTERNAL MODULE CTRL Dialog Box – Set for Broadband to 145 GHz below.

The choices for use with the MA25x00A, 3743X and 3744X modular heads are:

The MA25300A, MA25400A, 3743x and 3744x modules have independent source and receiver paths that can be selected from the above dialog. The selections are defined as follows:

Use the receiver in the remote modules above the receiver breakpoint (30 GHz). Above this breakpoint, the VNA system LO will be set appropriately in terms of frequency and power, the test set configured, and the VNA rear panel IFs will be activated.

Use the source multipliers in the remote modules above the source breakpoints (54 GHz). Above the first breakpoint, the VNA synthesizers will be set appropriately, the test set configured as needed, and ALC leveling prepared (see below). Note that the above and below 54 GHz power control setting apply when this source feature is enabled (more details earlier in this chapter).

This enables a fixed delay at the beginning of the band. This could be useful for certain slow settling DUT measurements or for very low power levels.

The default operation of the 3739-based modes (when not in multiple source) is to use IF leveling in order to get wide power ranges but if the source and receiver frequencies are not close enough (or the receiver is not enabled), then an IF is not available for leveling. The leveling defaults to RF in multiple source 3739-based modes with broadband/mmWave and this is recommended unless one knows the IF will be available (up to about 100 MHz) in the module for leveling. Separate ALC calibrations are available for RF and IF leveling and the system will automatically index the correct calibration table.

This feature allows the user to select three different leveling sub-choices when the Source Leveling type selected is RF.