07_RH79_SM_ant

7/31/2019 07_RH79_SM_ant

http://slidepdf.com/reader/full/07rh79smant 1/8

Issue 1 02/2006 Company Confidential © 2006 Nokia Corporation

Nokia Customer Care1255 (RH-79)

Mobile Terminal

Antenna Description and

Troubleshooting

7/31/2019 07_RH79_SM_ant


1255 (RH-79) Antenna Description and Troubleshooting

Page 2 © 2006 Nokia Corporation Company Confidential Issue 1 02/2006

Contents Page

Introduction............................................................................................................... 3

Visual Quality Requirements .............................................................................3

Failures and Corrective Measures........................................................................... 3

PIFA Antenna.....................................................................................................4

Damaged RF feed point or Ground Pins ...........................................................4

Damaged IHF Speaker Spring Pins...................................................................5

Obstructed Speaker, RF feed point, and Ground pads ........................................... 5

Grounding of Display Frame..............................................................................6

RF Connector Failure........................................................................................7

7/31/2019 07_RH79_SM_ant


1255 (RH-79) Nokia Customer Care Antenna Description and Troubleshooting

Issue 1 02/2006 © 2006 Nokia Corporation Company Confidential Page 3

Introduction

The mobile terminal incorporates an internal antenna. This antenna arrangement is

used for Cellular frequency bands. The internal antenna assembly adopts PlanarInverted-F Antenna (PIFA) structure used for the cellular engine.

Visual Quality Requirements

Following are the minimum acceptable visual quality requirements of the internal

antenna assembly:

z Wear the gloves to assemble the antenna. Don’t touch the antenna

radiator with bare hands.

z No visual cracks or mechanical defects.

z No oil, dirt, or particles are present on the parts.

z Radiator must be aligned with the plastic housing.

z Radiator must be flat with no warping.

z The length of all pins must be identical and the pins align.

Failures and Corrective Measures

The internal antenna is assembled into the D Cover Assembly as shown in Figure 1.

If no internal antenna is installed, the antenna gain is degraded by more than 20

dB.

z If the internal antenna is missing, install SAM Module.

z If the radiator looks damaged obviously, replace it with a new SAM

Module.

Figure 1: D Cover Assembly

Internal Antenna Holder / Carrier

The back of S eaker

7/31/2019 07_RH79_SM_ant




PIFA Antenna

The internal antenna has a planar-inverted F antenna (PIFA) radiator attached to the

plastic carrier. An integrated hand-free (IHF) mini speaker is integrated inside the plastic

carrier.

Note: The speaker is an integral part of the SAM Module to ensure optimum RF performance and must not be replaced individually.

Figure 2: The top view of internal antenna

Damaged RF feed point or Ground Pins

The two pins (spring clips) of the antenna must properly connect the PWB.

z If the main antenna’s RF feed point pin does not touch the PWB, the

antenna gain degrades by more than 17 dB.

z If the ground pin of the main antenna does not touch the PWB, the

antenna gain degrades from 0.5 to 1 dB.

z If either the RF feed pin or ground pin are broken or bent such that either

pin does not touch the PWB, replace the SAM Module.

z If either the RF pin or ground pin springs appear damaged, replace the

SAM Module.

Figure 3: The back view of internal antenna

RF feed pin

Ground pin

IHF mini speaker spring

7/31/2019 07_RH79_SM_ant




Damaged IHF Speaker Spring Pins

In Figure 3, the two spring pins on the back of the internal antenna must properly

touch the PWB. If not, the Cellular gain of the internal antenna degrades by 0.5 dB

and no audio will emit from the speaker.

Obstructed Speaker, RF feed point, and Ground pads

If any of the RF feed point pad or ground pad is obstructed, removed, or covered,

the antenna pin does not touch the PWB and the antenna performance degrades. If

any of the speaker pads are obstructed, removed, or covered, the speaker’s spring

pins does not touch the PWB and the cellular antenna performance could degrade.

z If corrosion is present or the pad is missing, replace the PWB.

z If a pad is obstructed or covered by something, clear and/or clean the

pad.

Figure 4: PWB layout of IHF speaker, RF feed point, and ground pads

Speaker pads

RF feed point pad

Ground pad

7/31/2019 07_RH79_SM_ant




Grounding of Display Frame

The display frame is grounded to the PWB through 4 ground panels. The display

frame grounding needs to touch the PWB. If not, the radio performance will be

impacted.z If the clips/tabs do not touch the ground of the PWB, or are corroded, or

are obstructed, replace the LCD Module Shielding Assy.

Figure 5: Display assembly ground points

Display frame grounding through screw

Display frame grounding through screw

Dis la frameround tabs

Dis la frameround tabs

7/31/2019 07_RH79_SM_ant




RF Connector Failure

The RF connector fails when it does not properly connect the RF input terminal to

the RF output terminal during the SMT. If this happens the antenna gain degrades

by 25 dB. Check this by testing the resistance value between the RF input and RFoutput of the RF connector and see if the value is close to zero. If the RF input is

not connected properly to the RF output, replace the RF connector.

Note: Perform the resistance value test without a RF cable attached to the RF

connector. Because the RF connector is also a switch, the RF output is

disconnected from the RF input when a RF cable is inserted into the RF connector.

z RF input terminal – connect to duplexer.

z RF output terminal – connect to the antenna pad through antenna match

circuit.

z RF connector terminal – connect to a RF coaxial cable.

RF output terminal RF input terminalRF output terminal RF input terminal

Figure 6: RF input / output terminal

Note:

• MSM6000 is underfilled and can not be replaced.

• Memory IC is underfilled and can not be replaced.

• The Shielding Case Assy can not be reused after removal.

• After using the heatgun, the domesheet needs to be replaced.

7/31/2019 07_RH79_SM_ant




This page intentionally left blank.

Documents

07_RH79_SM_ant