Frequently Asked Questions

Q: What are the handling instructions for current OTA phantoms for mmWave applications in the frequency range 3 to >100 GHz delivered after May 2019?

A: The second generation of OTA phantoms for mmWave applications delivered after May 2019 has a special low-loss coating that mimics the human skin structure and extends the frequency range of these phantoms beyond 100 GHz.  The coating of the second generation is mechanically very robust and does not need special handling other than the usual handling of the phantoms. 

Q: What are the handling instructions for OTA phantoms for mmWave applications in the frequency range 3 to >100 GHz delivered before May 2019?

A: The first generation of OTA phantoms for mmWave applications delivered before May 2019 has a special low-loss coating that mimics the human skin structure and extends the frequency range of these phantoms beyond 100 GHz. Although the coating of the first generation of mmWave phantoms has very similar dielectric properties and OTA performance as the second generation, and is durable and stable, it can be damaged by impact or strong pressure. We recommend to handle these phantoms with extra care, to avoid dropping and hitting the phantom against other objects during assembly, and to store them in their original wrapping to avoid damage due to hard surfaces. When positioning devices on the phantom, avoid the use of adhesive tapes or anything that would pull on the coating and cause tears. 

Q: How can I prevent the actuation of mobile phone side keys during measurements?

SHO-PG-V1 Press Guards are used to prevent the actuation of the side-key buttons on mobile phone devices during testing with SHO-V3RW-C/LW-C phantoms. They are designed for the purpose of "grommets" introduced in CTIA OTA test plan V3.6. SHO-PG-V1 rolls will be included in all SHO-V3RW-C/LW-C hand phantom shipments starting in January 2017. 

Q: What is the difference between the CTIA designed SHO-V3RW-C/LW-C and SPEAG's original SHO-V3RW/LW?

A: Both hand phantoms can be used for testing of ultra-wide devices and provide similar realistic hand grips. CTIA decided to change the palm contact area to have smaller dielectric loads of the device under test in the corner and also to provide a smaller difference in OTA results obtained with hand phantoms for PDA and ultra-wide devices. Only SHO-V3RW-C/LW-C is included in the CTIA OTA test plan.

Q: Do CTIA designed SHO-V3RW-C/LW-C and SPEAG's original SHO-V3RW/LW hand phantoms require different wrists?

A: Yes. For data-mode testing, either hand can be mounted on the SHO-FX-V5 data-mode fixture but only when combined with the appropriate respective data-mode wrist: SHO-RW/LW-DWV4 for SHO-V3RW/LW and SHO-RWC/LWC-DWV4 for SHO-V3RW-C/LW-C.

Q: What has been changed in SPEAG's latest V2 talk-mode fixture SHO-FTMV2?

A: The new SHO-FTMV2 was designed to accommodate the SHO-V3RW-C/LW-C hand phantoms. These hands are wider than SPEAG's original design (SHO-V3RW/LW) and are not compatible with SPEAG's V1 talk-mode fixture (SHO-FTMV1). The red plates have been lowered by ~20 mm on the SHO-FTMV2 to accommodate the wider hands. The SHO-FTMV2 is compatible with all SPEAG hand phantoms used with talk mode-fixture SHO-FTMV1 using the corresponding adaptors SHO-Rx/Lx-ADTMFV2.

Q: Can I use the hand phantoms that I was using with SHO-FTMV1 talk mode fixture with the new SHO-FTMV2 talk mode fixture?

A: Yes. All SPEAG SHO-, SHO3TO10- and mmW-SHO hand phantoms used with talk mode-fixture SHO-FTMV1 are compatible with the new SHO-FTMV2, using with the corresponding adaptors SHO-Rx/Lx-ADTMFV2. All the SHO- and SHO3TO6/3TO10 hand phantoms shipped after July 2016 are equipped with these adaptors. Additionally, an upgrade set (SHO-FTMV2 upgrade set) is available for customers with existing SHO-FTMV1 who are purchasing a new SHO-FTMV2 talk mode-fixture. This upgrade set includes a full set of adaptors. Adaptors can also be purchased individually. For full instructions, please see our OTA Manual. 

Q: What is the difference between SAM-V4.5BSE and SAM-V4.6BSE?

A: SAM-V4.6BSE and SAMV4.6BS3TO6E SAM head phantoms with lossy ears are SPEAG's latest addition to the EM Phantoms family. They are designed for performance evaluation of devices with antennas operating close to the human head, ears or face, such as hearing aids, wireless headsets like the new generation Virtual Reality (VR) headsets or smart glasses and goggles. The redesigned smooth outer shell is optimized for the best fitting of devices. The head geometry is based on the IEEE and CTIA SAM data and the material properties of the gel filling are compliant with CTIA requirements.

Q: Why is a cube of lossy silicone shipped together with the hand phantoms?

A: The cube samples are produced together with the hand phantoms and from the same silicone-carbon mixture. Cut surfaces on the cubes are used to determine bulk material properties as defined by the CTIA OTA test plan. The details of these measurements are given in the certificates of material properties delivered together with the hand phantoms. 

We recommend to keep these cubes in a safe place in case of future re-evaluation of the hand properties, e.g., for recertification of hand phantoms, where needed.

Q: What is the recommended usage time of SPEAG's hand phantoms?

A: SPEAG continually monitors the quality of our SHO-hand phantoms to ensure the accuracy and repeatability of our customer's phantom-based OTA measurements. Our internal studies of the hand phantoms demonstrate that the material remains highly stable over time. However, investigation of used hands that have been returned to our labs shows that prolonged use and non-optimal operation and storage conditions can alter the OTA performance of the hands. On the basis of these observations, SPEAG strongly recommends that all SHO-hand phantoms be recertified after at most 3 years of use or in the case of any visible damage.

Q: How can I clean the hand phantoms?

A: SPEAG recommends that the hand phantoms are kept under clean conditions and handled with clean hands or gloves. In case cleaning becomes necessary, we recommend using a damp cloth with deionized water. Do not use solvents or alcohol. 

Q: How are SHO-V2 and SHO-V3 hands different? 

A: In 2015 SPEAG released SHO-V3 hand phantoms enabled with a click-in mechanism for more robust attachment to data-mode wrists in a hand-only test setup and to the forearm SHO-RFP/LFP-V2 The lossy silicone part of the two versions are identical and manufactured from the same mold. The overall material composition of the hand and fixture is also identical when the hand is mounted on the data wrists. No differences in OTA performance are therefore expected. This was verified in a study where the OTA performance of SHO-V3 hands was evaluated and compared to that of SHO-V2 hands with a number of devices in a CTIA certified OTA test lab; no significant difference in measured TRP values was observed. 

Q: If a gel-filled head phantom is cracked, will the OTA performance be affected?

A: Yes. Exposure to air can significantly alter the dielectric properties of the gel filling and hence the OTA performance of the head phantom. If any damage is noticed on the phantom please contact us as soon as possible and we will gladly evaluate if a repair is possible.

Q: What are the recommended storage conditions for the gel-filled SAM head phantoms?

A: The head phantom shall be stored at normal room temperature around 22°C. It must not be exposed to temperatures above 30°C or below 2°C or to direct sunlight radiation (heating up). 

Q: What is the recommended usage time for SPEAG's gel-filled head and torso phantoms?

A: We have demonstrated the stability of the gel filling over a min of five years when the head phantom is kept sealed and under the stated temperature conditions (22 +/- 5 C). It is not possible to verify the gel parameters without exposing the gel to the environment. Any opening will lead to the inclusion of air into the sealed volume and degrade the homogeneity of the product. Only a complete re-fill of the gel under manufacturing conditions will guarantee the full performance. During this process, gel samples are generated and individually tested for conformity to the standard requirements. SPEAG recommends such a re-fill on a five-year basis.

Q: What are the differences between CTIA generic forearm phantom (SHO-GFPC-V1) and SPEAG's original forearm phantom (SHO-RFP/LFP-V2)?

A: Both forearm phantoms can be used for OTA evaluations of wireless wrist-worn devices. The SHO-GFPC-V1 was developed in collaboration with CTIA: the anatomical hand was not included to enable easy positioning of wrist-worn devices onto the forearm phantom, in particular to allow fixed circumference, rigid "bangle"-type devices to be snugly fitted at locations deviating from the target engraved marking as necessary, with minimum impact (i.e. without bringing them nearer to/farther from a hand phantom discontinuity) and to enable use of a single phantom for both left and right forearm testing. The simplified shape for the forearm was selected to eliminate the ulna bump in the forearm, to enable repeatable positioning of wrist-worn devices on the forearm phantom and to enable the use of a single phantom for both left and right forearm testing.