FAQ

MilliBox Systems

What do I get when I buy a MilliBox System?

A MilliBox antenna test system is composed of two main parts: a chamber and a gimbal.
  1. The chamber is shipped flat-packed and partially assembled. An assembly manual and tools are provided to guide you to finish the chamber assembly. A typical assembly will require 2 people and can be completed in a couple hours.
  2. The gimbal comes with the positioner, laser guide, power supply, USB dongle, software controller written in Python, and a detailed user manual. This allows full control of the gimbal movement and calibration. There is also a matching horn post and horn clamp that can accommodate waveguide flanges from WR2.2-WR34.
The following ARE NOT included with the MilliBox and must be provided separately: horn antenna, waveguide-to-coax adapters, cables, and test equipment.

Do you only sell the chamber and gimbal as a bundle, or can I buy the components separately?

We can sell the chamber by itself or the gimbal as a stand-alone unit. Please contact us at millibox@milliwavess.com for more information.

MilliBox Chambers

Which MilliBox size is right for my mmWave measurements?

MilliBox is intended to be used for over-the-air (OTA) measurements of antennas operating in the far-field region. The far-field region depends on the frequency and antenna size. If the maximum linear dimension of the antenna is D and the wavelength is λ, then the common rule-of-thumb is that the measurement distance R > 2D²/λ.

MilliBox can be configured to have different R. The table below shows the calculated D for different operating frequencies and MilliBox configurations.

MAX ANTENNA DIMENSION (D IN CM) FOR FAR-FIELD MEASUREMENT
24GHz28GHz39GHz57GHz60GHz71GHz77GHz95GHz
MBX026.96.45.44.54.44.03.93.5
MBX039.38.67.36.05.95.45.24.7
MBX0411.110.38.77.27.06.56.25.6

If I buy a MilliBox now, can I extend it to be longer if my requirements change?

Absolutely! One of the key benefits of the MilliBox product line is the modularity. We sell extension kits that can be used to extend your existing MilliBox by one or more modules to meet your evolving needs.

Since MilliBox is configurable, can I build a chamber of any size and shape, or are there some limitations?

MBX02, MBX03, and MBX04 are the most popular solutions that are applicable to a large range of mmWave applications. These chambers have the benefits of being compact, lightweight, and portable, and can achieve a far-field distance ranging from around 70cm to 2m.

However, we know that your application may have special requirements, and we have worked with numerous customers in the past to tailor our chambers to their unique needs. If you need something different than our standard products, please contact us at millibox@milliwavess.com, and we would be happy to have a technical discussion to determine whether a custom MilliBox could work for you.

How do I connect signal and power to my DUT?

The MilliBox has 8cm (3″) diameter direct pass-through holes in the deck located beneath the gimbal. This hole allows direct routing of all of the connections needed for the DUT. This could include a combination of RF, analog, and digital signals along with power. By allowing a direct connection without ports, this provides the most flexibility and also minimizes the RF loss when connecting to test equipment that is placed in the instrument bays below the MilliBox.

MilliBox Gimbals

What size and weight of the device-under-test (DUT) can we expect the gimbal to handle?

  • The standard GIM01 that comes with a MilliBox is rated for a DUT of up to 0.5kg. The mounting area is spaced for a DUT of up to 11cm (W) x 20cm (H) x 4cm (D).
  • The GIM03 can accommodate larger loads. The max DUT size on the GIM03 has been increased to 27cm (W) x 30cm (H) x 10cm (D), with a max weight of 3kg.
  • The single-axis GIM1D has no restriction on DUT width since the DUT is mounted from the back. The weight limit for a GIM1D is 5kg.

What is the angular coverage and stepping resolution of the MilliBox gimbal?

The 2-axis gimbals (GIM01, GIM03) can rotate -180° to +180° in both the H and V planes. The 1-axis GIM1D can rotate -180° to +180° in the H plane only. All gimbals use stepper motors with absolute position encoders and have a resolution of < 0.1°.

What is the GIM1D and when would I need it?

The GIM1D is a single-axis gimbal that rotates in the H-plane (azimuth) only. The key benefits are:

  1. It can hold a larger DUT – no limit on DUT width and a weight up to 5kg.
  2. Since the mounting is from the back, this gimbal provides the largest unobstructed view when measuring at very wide azimuth angles.

Software

What software is provided and what does it do?

The provided Python software fully controls the gimbal movement and calibration. In addition, the software includes sample code to interface to typical test equipment. Since the only requirement for the test equipment is that it needs to be able to be controllable using the Python VISA API, this covers the majority of modern test equipment from most manufacturers. Typical sweeps (1D, 2D) and plotting functions for radiation pattern characterization are also included.

The complete Python software is provided in source. It is common for our customers to use it as a base and add software enhancements to the code that are specific to their DUT, their test equipment, or their measurent. It is also possible to port the Python code to other environments such as MATLAB, LabView, or Keysight VEE.

If I need to change between GIM01, GIM1D, and GIM03, do I need to completely rewrite my software?

No, you do not need to rewrite the software! The software for the GIM01, GIM1D, and GIM03 is fully compatible. The only difference is that for the single-axis GIM1D, some functions that control the V motor are disabled.

Options and Customizations

What options and accessories are available?

We offer many different options and accessories that include, but are not limited to: receiver mounts for mixers, dual-polarized horn antenna mounts, trihedral reflector mounts for radar, linear actuators, and sniffer mounts.

In addition, it is possible to customize various parts of the MilliBox to tailor it to your application. This includes creating custom DUT mounts to attach the DUT to the gimbal, changes to the panels with additional holes or mounting points, and adjustments to the gimbal platform.

Please contact us at millibox@milliwavess.com to discuss your requirements.