A.2.2.4 Hand phantom grips
37.5443GPPConformance testingRelease 16TSUniversal Terrestrial Radio Access (UTRA) and Evolved UTRA (E-UTRA)User Equipment (UE) Over The Air (OTA) performance
Hand phantom grips are based on human factor studies that were done to record how a phone of certain form factor was gripped by a large sample of people. Based on the grip study findings, three grip designs are chosen for 40- to 56-mm wide devices: one for mono-block devices used in a voice call, another for fold devices in a voice call, and a third for “data mode” grip, simulating for example web browsing, Figure A.2.2.4-1 shows mono-block and fold grips [20]. Grip studies showed that devices wider than 56 mm (generally PDA and touch screen devices) could be conveniently accommodated by a single grip to cover primary use cases, voice calls and data browsing [20].
Each grip is used with a spacer that is designed for repeatable positioning of terminals to the grips. The material for the monoblock palm spacer shall be hollow with a wall thickness less than 2 mm and a dielectric constant of less than 5.0 and a loss tangent of less than 0.05 or it shall be solid with a dielectric constant of less than 1.3 and a loss tangent of less than 0.003. Touch fastener material may be used to affix the DUT to the palm spacer.
Figures A.2.2.4-1 and A.2.2.4-2 below illustrate the right-handed and left-handed mono-block and fold grips, respectively.
Figure A.2.2.4-1: Right-handed grips defined to hold mono-block and fold UEs during voice calls
Figure A.2.2.4-2: Left-handed grips defined to hold mono-block and fold UEs during voice calls
Figures A.2.2.4-3 and A.2.2.4-4 below illustrate the right-handed and left-handed data browsing with narrow UEs and PDA grips, respectively.
Figure A.2.2.4-3: Right-handed grip defined for data browsing with narrow UEs and grip for holding PDA type of devices
Figure A.2.2.4-4: Left-handed grip defined for data browsing with narrow UEs and grip for holding PDA type of devices
CAD models in Table A.2.2.4-1 define exact finger locations and spacers for the specified grips. The files are available in a subfolder of the archive area for this specification.
Table A.2.2.4-1: CAD models for specified hand phantom grips and spacers
|
Hand phantom grip |
Grip CAD file name |
Grip spacer file name |
|
Right Mono-block grip |
25914-b10_CAD_hand1.zip |
25914-b10_CAD_spacer1.zip |
|
Right Fold grip |
25914-b10_CAD_hand2.zip |
25914-b10_CAD_spacer2.zip |
|
Right Narrow data browsing grip |
25914-b10_CAD_hand3.zip |
25914-b10_CAD_spacer3.zip |
|
Right PDA grip |
25914-b10_CAD_hand4.zip |
25914-b10_CAD_spacer4.zip |
|
Left Mono-block grip |
25914-b10_CAD_hand5.zip |
25914-b10_CAD_spacer5.zip |
|
Left Fold grip |
25914-b10_CAD_hand6.zip |
25914-b10_CAD_spacer6.zip |
|
Left Narrow data browsing grip |
25914-b10_CAD_hand7.zip |
25914-b10_CAD_spacer7.zip |
|
Left PDA grip |
25914-b10_CAD_hand8.zip |
25914-b10_CAD_spacer8.zip |
A.2.2.5 Mechanical Requirements of Hand Phantoms
The hand phantoms shall be constructed of a material that is sufficiently flexible to accommodate the range of devices specified in A.2.2.4. The material shall also be made sufficiently stiff that the hand grip remains constant under rotation.
Adequate material stiffness of the hand phantom is necessary to maintain high repeatability of OTA measurements. The stiffness of the hand material shall be verified by measuring the deflection of the index finger of a moulded monoblock hand phantom under a given weight. Test procedure is following;
1. Position the hand phantom such that the index finger is horizontal.
2. Apply an indicator needle that extends horizontally 55 mm ±1 mm beyond the tip of the index finger.
3. Record the position of the indicator needle on a vertical scale.
4. Apply 20 g ±0.2 g of weight centred 6 mm ±0.5 mm from the tip of the index finger towards the hand.
5. Record the new position of the indicator needle on a vertical scale.
The deflection of the index finger of the hand phantom shall be between 2 and 5 mm. Deflection less than 2 mm per 20 g weight indicates a material that is too rigid. Deflection greater than 5 mm per 20 g weight indicates a material that is too soft.
Figure A.2.2.5-1: Hand phantom stiffness test
Figure A.2.2.5-2: A weight container designed for a hand phantom stiffness test
A weight container presented in Figure A.2.2.5-2 may be used in the stiffness test. It is assumed that other grips will have similar stiffness as the monoblock hand from the same material. Therefore, a stiffness test of the monoblock hand alone is considered sufficient.
The characteristics of position of the hand phantom such that the index finger is horizontal are specified in Table A.2.2.5-1.
Table A.2.2.5-1: Characteristics of position of the hand phantom
|
ID |
Hand Grip Placement |
Characteristic Type |
|
0 |
Low |
Shift Up |
|
1 |
Medium |
No Shift |
|
2 |
High |
Shift Down |
The characteristics of deflection of the index finger of the hand phantom are specified in Table A.2.2.5-2.
Table A.2.2.5-2: Characteristics of deflection of the index finger of the hand phantom
|
ID |
Deflection of Index Finger (df) Placement |
Characteristic Type |
|
0 |
df ≥ 2 mm per 20g |
Rigid |
|
1 |
2mm < df ≤ 5mm per 20g |
Stable |
|
2 |
df > 5mm per 20g |
Soft |