11b347r-rfcep39v01 report-微星 ms-16f2 …faenl.msi.com/ftp/ce documents/notebook/ms-16f2x...

Report No. 11B347R-RFCEP39V01

Page: 1 of 38

Test Report

For：Intel

Product Name Notebook Model No. MS-16F1, MS-16F2, MS-16F3, MS-16F4, MS-16F5,

MS-16F6, MS-16F7, MS-16F8, MS-16F9, MS-16FA, MS-16FB, MS-16FC, MS-16FD, MS-16FE, MS-16FF, MS-16FG, MS-16FH, MS-16FI, MS-16FJ, MS-16FK, MS-16FL, MS-16FM, MS-16FN, MS-16FO, MS-16FP, MS-16FQ, MS-16FR, MS-16FS, MS-16FT, MS-16FU, MS-16FV, MS-16FW, MS-16FX, MS-16FY, MS-16FZ, GTzzzz (z= 0~9, a~j, A~J or blank)

Transmitter Module Intel / 130BNHMW Antenna Kit JEM: 1510-0105-0044 (Main)

1510-0105-0043 (Aux)

Applicant MICRO-STAR INT'L Co., LTD.

Address No. 69, Li-De St., Jung-He District, New Taipei City, Taiwan

Date of Receipt Nov. 15, 2011

Date of Test Nov. 21, 2011


Report Version V1.0

The test results relate only to the samples tested.

The test report shall not be reproduced except in full without the written approval of QuieTek Corporation.


Page: 2 of 38

Test Report Cert i f icat ion Date of Test: Nov. 21, 2011 Report No.: 11B347R-RFCEP39V01

Product Name Notebook

Applicant MICRO-STAR INT'L Co., LTD.

Address No. 69, Li-De St., Jung-He District, New Taipei City, Taiwan

Manufacturer MICRO-STAR INT'L Co., LTD.

Model No. MS-16F1, MS-16F2, MS-16F3, MS-16F4, MS-16F5, MS-16F6, MS-16F7,

MS-16F8, MS-16F9, MS-16FA, MS-16FB, MS-16FC, MS-16FD, MS-16FE,

MS-16FF, MS-16FG, MS-16FH, MS-16FI, MS-16FJ, MS-16FK, MS-16FL,

MS-16FM, MS-16FN, MS-16FO, MS-16FP, MS-16FQ, MS-16FR, MS-16FS,

MS-16FT, MS-16FU, MS-16FV, MS-16FW, MS-16FX, MS-16FY, MS-16FZ,

GTzzzz (z= 0~9, a~j, A~J or blank)

Transmitter Module Intel / 130BNHMW

Antenna Kit JEM: 1510-0105-0044 (Main)

1510-0105-0043 (Aux)

EUT Rated Voltage AC 100-240V, 50-60Hz

EUT Testing Voltage AC 230V/50Hz

Trade Name msi

Measurement Standard ETSI EN 300 328:V1.7.1 (2006-10)

Test Result Complied

The test results relate only to the samples tested. The test report shall not be reproduced except in full without the written approval of QuieTek Corporation.

Documented By :

(Senior Engineering Adm. Specialist /

Anita Chou)

Tested By :

( Engineer / Henk Huang)

Approved By :

( Manager / Vincent Lin)

Accredited by TUV, DNV, Nemko and NIST (NVLAP)


Page: 3 of 38

TABLE OF CONTENTS Description Page 1. GENERAL INFORMATION .....................................................................................................................4 1.1. EUT Description............................................................................................................................................4 1.2. CRTU-ABG Software Parameter ..................................................................................................................5 1.3. Test Channel and Data Rate ..........................................................................................................................5 1.4. Tested System Details ...................................................................................................................................6 1.5. Configuration of Tested System....................................................................................................................6 1.6. EUT Exercise Software .................................................................................................................................6 1.7. Test Facility ...................................................................................................................................................7 2. Equivalent Isotropic Radiated Power ........................................................................................................8 2.1. Test Equipment..............................................................................................................................................8 2.2. Test Setup ......................................................................................................................................................8 2.3. Test Condition ...............................................................................................................................................8 2.4. Limits.............................................................................................................................................................8 2.5. Test Procedure ...............................................................................................................................................9 2.6. Test Specification ..........................................................................................................................................9 2.7. Uncertainty ....................................................................................................................................................9 2.8. Test Result .....................................................................................................................................................9 2.9. Test Data of Equivalent Isotropic Radiated Power......................................................................................10 3. Antenna Assembly Summary....................................................................................................................11 4. Transmitter Spurious Emission ................................................................................................................12 4.1. Test Equipment............................................................................................................................................12 4.2. Test Setup ....................................................................................................................................................13 4.3. Test Condition .............................................................................................................................................14 4.4. Limits...........................................................................................................................................................14 4.5. Test Procedure .............................................................................................................................................15 4.6. Test Specification ........................................................................................................................................15 4.7. Uncertainty ..................................................................................................................................................15 4.8. Test Result ...................................................................................................................................................15 4.9. Test Data of Spurious Emission ..................................................................................................................16 5. Receiver Spurious Emission......................................................................................................................19 5.1. Test Equipment............................................................................................................................................19 5.2. Test Setup ....................................................................................................................................................20 5.3. Test Condition .............................................................................................................................................21 5.4. Limits...........................................................................................................................................................21 5.5. Test Procedure .............................................................................................................................................21 5.6. Test Specification ........................................................................................................................................22 5.7. Uncertainty ..................................................................................................................................................22 5.8. Test Result ...................................................................................................................................................22 5.9. Test Data of Spurious Emission ..................................................................................................................23 6. Measurement Uncertainty Values............................................................................................................26 7. EMC Reduction Method During Compliance Testing ...........................................................................27 Attachment 1: EUT Test Photographs...............................................................................................................28 Attachment 2 : EUT Detailed Photographs.......................................................................................................29


Page: 4 of 38

1. GENERAL INFORMATION

1.1. EUT Description

Product Name Notebook

Trade Name msi

Model No.

MS-16F1, MS-16F2, MS-16F3, MS-16F4, MS-16F5, MS-16F6, MS-16F7,

MS-16F8, MS-16F9, MS-16FA, MS-16FB, MS-16FC, MS-16FD, MS-16FE,

MS-16FF, MS-16FG, MS-16FH, MS-16FI, MS-16FJ, MS-16FK, MS-16FL,

MS-16FM, MS-16FN, MS-16FO, MS-16FP, MS-16FQ, MS-16FR, MS-16FS,

MS-16FT, MS-16FU, MS-16FV, MS-16FW, MS-16FX, MS-16FY, MS-16FZ,

GTzzzz (z= 0~9, a~j, A~J or blank)

Transmitter Module Intel / 130BNHMW

WFM Number DCA97102112E

Frequency Range 802.11b/g/n-20MHz 2412-2472MHz , 802.11n-40MHz: 2422-2452MHz

Bluetooth: 2402-2480MHz

Number of Channels 802.11b/g/n-20MHz: 13, 802.11n-40MHz: 7

Bluetooth: 79

Maximum Data Rate 802.11b: 11Mbps, 802.11g: 54Mbps, 802.11n: up to 150Mbps

Bluetooth: 1-3Mbps

Channel Separation 802.11bgn: 5 MHz ; Bluetooth: 1MHz

Antenna Gain Refer to the table “Antenna List”

Antenna Type PIFA

Type of Modulation DSSS/OFDM

Channel Control Auto

Power Adapter MFR: DELTA, M/N: ADP-180HB B

Input: AC 100-240V~2.25A, 50-60Hz

Output: DC 19V, 9.5A

Cable Out: Shielded, 1.8m, with two ferrite cores bonded.

Antenna List No. Manufacturer Part No. Antenna Type Peak Gain

1 JEM 1510-0105-0044 (Main)

1510-0105-0043 (Aux)

PIFA

1.85dBi for 2.4GHz


Page: 5 of 38

1.2. CRTU-ABG Software Parameter

Test Mode Data Rate (Mbps) Antenna Parameter Value Channel Frequency (MHz)

A 24.5 1 2412 A 24.5 7 2442

802.11n (20MHz)

MCS0

A 24.5 13 2472

Quickly measure the Duty Cycle again of the signal. When using DRTU Version 1.2.12-0197, this will depend on the version and the bit rate. The duty cycle x delivers a correction factor to determine EIRP.

1.3. Test Channel and Data Rate

It is necessary to measure e.i.r.p on following frequencies: 802.11n-20MHz –2.4GHz band: 2412MHz, 2442MHz, 2472MHz. Tests are performed at following date rates: 802.11n-20Mbps – MCS0 in 2412MHz, 2442MHz, 2472MHz. Note: 1. QuieTek verified all construction and function in typical operation. All the test modes were carried out with

the EUT in normal operation, which was shown in this test report and defined as:

Mode 1: Transmit, 802.11n(20MHz)-2.4GHz band EMI Test Mode

Mode 2: Receive, 802.11n(20MHz)-2.4GHz band


Page: 6 of 38

1.4. Tested System Details

The types for all equipment, plus descriptions of all cables used in the tested system (including inserted cards) are:

Product Manufacturer Model No. Serial No. FCC ID Power Cord

N/A

Signal Cable Type Signal cable Description

N/A

1.5. Configuration of Tested System

1.6. EUT Exercise Software

(1) Setup the EUT as shown in Section 1.5.

(2) Execute the continuous transmission software of Intel DRTU Version 1.2.12-0197.

(3) Setup the test mode, the test channel and the data rate.

(4) Press OK to start the continuous transmission.

(5) Verify that the EUT works correctly.

EUT


Page: 7 of 38

1.7. Test Facility

Ambient conditions in the laboratory:

Items Test Item Required (IEC 68-1) Actual

Temperature (C) 15-35 22-27

Humidity (%RH)

ETSI EN 300 328

20-75 50-65

The related certificate for our laboratories about the test site and management system can be downloaded from QuieTek Corporation’s Web Site : http://www.quietek.com/tw/ctg/cts/accreditations.htm

The address and introduction of QuieTek Corporation’s laboratories can be founded in our Web site : http://www.quietek.com/

Site Description: File on Federal Communications Commission FCC Engineering Laboratory 7435 Oakland Mills Road Columbia, MD 21046

Registration Number: 92195

Accreditation on NVLAP NVLAP Lab Code: 200533-0 Site Name: Quietek Corporation Site Address: No.5-22, Ruishukeng, Linkou Dist., New Taipei City 24451,

Taiwan, R.O.C. TEL: 886-2-8601-3788 / FAX: 886-2-8601-3789 E-Mail: [email protected]


Page: 8 of 38

2. Equivalent Isotropic Radiated Power

2.1. Test Equipment

Equipment Manufacturer Model No Serial No. Last Cal.

Power Meter Anritsu ML2495A 6K00003357 May, 2011

Power Sensor Anritsu MA2411B 0738448 Jun, 2011

Note: All equipments upon which need to be calibrated are with calibration period of 1 year.

2.2. Test Setup

Conducted Power Measurement

2.3. Test Condition

The normal temperature and humidity conditions for tests shall be any convenient combination of

temperature and humidity within the following ranges:

- Temperature: +15°C to +35°C;

- Relative humidity: 20 % to 75 %.

2.4. Limits

802.11n-20MHz：(EN 300 328 V1.7.1—Clause 4.3.1.2) The effective radiated power is defined as the total power of the transmitter and is calculated

according to the test procedure. The effective radiated power shall be equal to or less than –10 dBW

(100 mW) e.i.r.p.

SMA Connecter

EUT Power

Meter

RF Cable


Page: 9 of 38

2.5. Test Procedure

The measurement is performed using normal operation of the equipment with test modulation applied.

The test procedure is as follows:

step 1:‧

- Using a suitable means, the output of the transmitter shall be coupled to a matched diode detector;

- The output of the diode detector shall be connected to the vertical channel of an oscilloscope.

- The combination of the diode detector and the oscilloscope shall be capable of faithfully

reproducing the envelope peaks and the duty cycle of the transmitter output signal.

- The observed duty cycle of the transmitter (Tx on/(Tx on +Tx off)) shall be noted as x, (0 < x < 1)

and recorded. For the purpose of testing, the equipment shall be operated with a duty cycle that is

equal to or more than 0,1.

step 2:‧

- The average output power of the transmitter shall be determined using a wideband, calibrated RF

power meter with a matched thermocouple detector or an equivalent thereof and, where applicable,

with an integration period that exceeds the repetition period of the transmitter by a factor 5 or more.

The observed value shall be recorded as “A” (in dBm).

- The e.i.r.p. shall be calculated from the above measured power output A, the observed duty cycle x,

and the applicable antenna assembly gain “G” in dBi, according to the formula:

P = A + G + 10 log (1/x);

P shall be recorded in the test report. (Not exceed the value specified in ETSI EN 300 328 V1.7.1 clause

4.3.1.2)

2.6. Test Specification

According to ETSI EN 300 328 V1.7.1 (2006-10) clause 5.7.2.2

2.7. Uncertainty

± 1.27dB

2.8. Test Result

The emission from the EUT was below the specified limits. The worst-case emissions are shown in

section 2.9. The acceptance criterion was met and the EUT passed the test.


Page: 10 of 38

2.9. Test Data of Equivalent Isotropic Radiated Power

Product : Notebook Test Item : Equivalent Isotropic Radiated Power Test Mode : Mode 1: Transmit, 802.11n(20MHz)-2.4GHz band

Frequency Reading level Antenna gain Cable loss Duty cycle EIRP Limit

(MHz) (dBm) (dBi) (dB) (dBm) (dBm)

802.11n (2.4G) 2412 15.85 1.85 0.5 0.99 18.24 20

802.11n (2.4G) 2442 15.92 1.85 0.5 0.99 18.31 20

802.11n (2.4G) 2472 15.94 1.85 0.5 0.99 18.33 20

Note: P is the effective radiated power as defined in clause 5.7.2.2 step 2，P(EIRP)=Reading Level+Antenna

Gain+Cable loss+10log(1/Duty cycle)

Test Result PASS


Page: 11 of 38

3. Antenna Assembly Summary

Peak Gain W/ Cable loss Antenna Part Number Manufacture Antenna Type

Frequency (MHz) Max Gain (dBi)

1510-0105-0044 (Main) JEM PIFA 2400-2500 1.85

1510-0105-0043 (Aux) JEM PIFA 2400-2500 1.77


Page: 12 of 38

4. Transmitter Spurious Emission

4.1. Test Equipment

The following test equipment are used during the radiated spurious emission test:

Test Site Equipment Manufacturer Model No./Serial No. Last Cal.

X Bilog Antenna Schaffner Chase CBL6112B/2673 Sep., 2011

X Horn Antenna Schwarzbeck BBHA9120D/D305 Sep., 2011

Horn Antenna Schwarzbeck BBHA9170/208 Jul., 2011

X Pre-Amplifier QTK QTK-AMP-01 / 0001 Jul., 2011

X Pre-Amplifier Agilent 8447D/2944A09549 Sep., 2011

Pre-Amplifier MITEQ AMF-4D-180400-45-6P July, 2011

X Spectrum Analyzer Agilent E4407B / US39440758 May, 2011

X Coaxial Cable QuieTek QTK-CABLE/ CAB5 Feb., 2011

CB # 3

X Controller QuieTek QTK-CONTROLLER/ CTRL3 N/A

Note:

1. All equipments that need to be calibrated are with calibration period of 1 year.

2. Mark “X” test instruments are used to measure the final test results.


Page: 13 of 38

4.2. Test Setup

Under 1GHz Test Setup

Fully soldered Metal Ground

Above 1GHz Test Setup


Above 18 GHz Test Setup

EUT

FRP Dome

Antenna Mast Horn Antenna Antenna height can be moved from 1m to 4m, Antenna and turntable distance 3m

3m

1 5m

Spectrum Amplifier

Receiver

EUT

FRP Dome

Antenna Mast Bilog Antenna Antenna height can be moved from 1m to 4m, Antenna and turntable distance 3m

3m

1.5m

EUT

FRP Dome


3m

1.5m

Spectrum Amplifier


Page: 14 of 38

4.3. Test Condition





4.4. Limits

802.11n-20MHz –2.4GHz band:

Transmitter limits for narrowband spurious emission

(EN 300 328 V1.7.1—Clause 4.3.6.2)

Frequency Range Limit when operating Measurement Bandwidth

30MHz to 1 GHz -36 dBm 100 kHz

Above 1 GHz to 12.75 GHz -30 dBm 100 kHz

1.8 GHz to 1.9 GHz

5.15 GHz to 5.3 GHz

-47 dBm 100 kHz

Receiver limits for narrowband spurious emission

(EN 300 328 V1.7.1—Clause 4.3.7.2)

Frequency Range Limit Measurement Bandwidth




Page: 15 of 38

4.5. Test Procedure

The EUT and its simulators are placed on a turn table which is 1.5 meters above ground. The turn table

can rotate 360 degrees to determine the position of the maximum emission level. The EUT was

positioned such that the distance from antenna to the EUT was 3 meters.The antenna can move up and

down between 1 meter and 4 meters to find out the maximum emission level.

Broadband antenna (calibrated bi-log and horn antenna) are used as a receiving antenna.

Both horizontal and vertical polarization of the antenna are set on measurement. And a high frequency

preamlifier were used increase the sensitivity of the measuring. In order to find the maximum emission,

all of the interface cables must be manipulated according to ETSI EN 300 328:V1.7.1 (2006-10) on

radiated measurement.

The additional notch filter below 1GHz was used to measure the level of harmonics radiated emission

during field strength of harmonics measurement. The bandwidth below 1GHz setting on the field

strength meter is 120 kHz, and 100 kHz bandwidth is adopted above 1GHz. The frequency range from

30MHz to 12.75GHz is checked.


According to ETSI EN 300 328:V1.7.1 (2006-10) clause 5.7.5

4.7. Uncertainty

± 3.9 dB above 1GHz

± 3.8 dB below 1GHz

4.8. Test Result




Page: 16 of 38

4.9. Test Data of Spurious Emission

Product : Notebook Test Item : Transmitter spurious emission Test Site : No.3 Chamber Test Mode : Mode 1: Transmit, 802.11n(20MHz)-2.4GHz band

TX Spurious Emission

Measurement level(dBm) Chennal / Frequency Measurement Frequency

Horizontal

235.64 -51.237

1799 -68.690

7236 -55.455

9648 -54.694

12060 -52.114

Measurement level(dBm) Measurement Frequency

Vertical

239.52 -46.263

4824 -55.577

7236 -55.594

9648 -53.233

12060 -51.981

CH01 / 2412MHz


Page: 17 of 38




Horizontal

239.52 -52.380

4884 -58.428

7326 -55.117

9768 -54.548

12210 -52.239


Vertical

235.64 -46.606

4884 -58.035

7326 -54.636

9768 -53.187

12210 -51.656

CH07 / 2442MHz


Page: 18 of 38




Horizontal

239.52 -52.852

4944 -58.721

7416 -54.149

9888 -53.618

12360 -51.589


Vertical

239.52 -47.106

4944 -59.943

7416 -54.175

9888 -53.033

12360 -51.845

CH13 / 2472MHz


Page: 19 of 38

5. Receiver Spurious Emission

5.1. Test Equipment

The following test equipment are used during the radiated spurious emission test:

Test Site Equipment Manufacturer Model No./Serial No. Last Cal. X Bilog Antenna Schaffner Chase CBL6112B/2673 Sep., 2011

X Horn Antenna Schwarzbeck BBHA9120D/D305 Sep., 2011

Horn Antenna Schwarzbeck BBHA9170/208 Jul., 2011

X Pre-Amplifier QTK QTK-AMP-01 / 0001 July, 2011

X Pre-Amplifier Agilent 8447D/2944A09549 Sep., 2011

Pre-Amplifier MITEQ AMF-4D-180400-45-6P July, 2011

X Spectrum Analyzer Agilent E4407B / US39440758 May, 2011

X Coaxial Cable QuieTek QTK-CABLE/ CAB5 Feb., 2011

CB # 3

X Controller QuieTek QTK-CONTROLLER/ CTRL3 N/A

Note: 1. All equipments that need to be calibrated are with calibration period of 1 year.

2. Mark “X” test instruments are used to measure the final test results.


Page: 20 of 38

5.2. Test Setup

Under 1GHz Test Setup


Above 1GHz Test Setup


Above 18 GHz Test Setup

EUT

FRP Dome


3m

1 5m

Spectrum Amplifier

Receiver

EUT

FRP Dome


3m

1.5m

EUT

FRP Dome


3m

1.5m

Spectrum Amplifier

Report No: 11B347R-RFCEP39V01

Page: 21 of 38

5.3. Test Condition





5.4. Limits

802.11n-20MHz –2.4GHz band:

Receiver limits for narrowband spurious emission

(EN 300 328 V1.7.1—Clause 4. 3.7.2)

Frequency Range Limit Measurement Bandwidth



5.5. Test Procedure

The EUT and its simulators are placed on a turn table which is 1.5 meters above ground. The turn table

can rotate 360 degrees to determine the position of the maximum emission level. The EUT was

positioned such that the distance from antenna to the EUT was 3 meters.The antenna can move up and

down between 1 meter and 4 meters to find out the maximum emission level.

Broadband antenna (calibrated bi-log and horn antenna) are used as a receiving antenna.

Both horizontal and vertical polarization of the antenna are set on measurement. And a high frequency

preamlifier were used increase the sensitivity of the measuring. In order to find the maximum emission,

all of the interface cables must be manipulated according to ETSI EN 300 328:V1.7.1 (2006-10) on

radiated measurement.

The additional notch filter below 1GHz was used to measure the level of harmonics radiated emission

during field strength of harmonics measurement. The bandwidth below 1GHz setting on the field

strength meter is 100 kHz, and 100 kHz bandwidth is adopted above 1GHz. The frequency range from

30MHz to 12.75GHz is checked.


Page: 22 of 38


According to ETSI EN 300 328:V1.7.1 (2006-10) clause 5.7.5

5.7. Uncertainty

± 3.9 dB above 1GHz

± 3.8 dB below 1GHz

5.8. Test Result




Page: 23 of 38

5.9. Test Data of Spurious Emission

Product : Notebook Test Item : Receiver spurious emissions Test Site : No.3 Chamber Test Mode : Mode 2: Receive, 802.11n(20MHz)-2.4GHz band

RX Spurious Emission


Horizontal

235.64 -62.774

2412 -68.330

4824 -63.566

7236 -56.257

9648 -53.618

12060 -51.773


Vertical

239.52 -61.150

2412 -66.513

4824 -61.941

7236 -55.226

9648 -54.542

CH01 / 2412MHz

12060 -52.065


Page: 24 of 38




Horizontal

235.64 -62.580

2442 -68.664

4884 -62.300

7326 -55.785

9768 -54.274

12210 -52.308


Vertical

239.52 -62.322

2442 -67.647

4884 -62.571

7326 -55.124

9768 -54.585

CH07 / 2442MHz

12210 -52.906


Page: 25 of 38




Horizontal

239.52 -62.073

2472 -68.423

4944 -62.310

7416 -54.653

9888 -53.716

12360 -51.209


Vertical

235.64 -63.409

2472 -68.066

4944 -62.324

7416 -54.214

9888 -53.933

CH13 / 2472MHz

12360 -52.310


Page: 26 of 38

6. Measurement Uncertainty Values

The maximum values of the absolute measurement uncertainties of the measurements defined in the

present document shall not exceed the values given below:

802.11n-20MHz-2.4G band：

Parameter Uncertainty

Total RF power, conducted 1.5 dB

All emissions, radiated 6 dB

Temperature 1oC

Humidity 5 %

DC and low frequency voltages 3 %

For the measurement methods according to the present document these uncertainty figures are valid to

a confidence level of 95 % calculated according to the methods described in ETR 028 [5], on

guidelines for estimating uncertainties in measuring methods.


Page: 27 of 38

7. EMC Reduction Method During Compliance Testing

No modification was made during testing.


Page: 28 of 38

Attachment 1: EUT Test Photographs

Front View of Spurious Emission Test

Front View of Spurious Emission Test (Horn)


Page: 29 of 38

Attachment 2 : EUT Detailed Photographs (1) EUT Photo

(2) EUT Photo


Page: 30 of 38

(3) EUT Photo

(4) EUT Photo


Page: 31 of 38

(5) EUT Photo

(6) EUT Photo


Page: 32 of 38

(7) EUT Photo

(8) EUT Photo


Page: 33 of 38

(9) EUT Photo

(10) EUT Photo


Page: 34 of 38

(11) EUT Photo

(12) EUT Photo


Page: 35 of 38

(13) EUT Photo

(14) EUT Photo


Page: 36 of 38

(15) EUT Photo

(16) EUT Photo


Page: 37 of 38

(17) EUT Photo

(18) EUT Photo


Page: 38 of 38

(19) EUT Photo

11b347r-rfcep39v01 report-微星 ms-16f2 …faenl.msi.com/ftp/ce documents/notebook/ms-16f2x...

Documents