Antenna: Description and Operation
65 02 05 (114) Aerial System
E70, E71, E81, E82, E87, E88, E90, E91, E92, E93, R55, R56
Introduction
The number of radio services (transmission of messages by radio) in the vehicle is constantly growing: Services for communication, navigation, radio and sensor systems. The number or aerials has also increased in line with the additional radio services.
> E70 [system overview ...]
> E71 [system overview ...]
> E81, E87 [system overview ...]
> E88 [system overview ...]
> E82, E90, E92 [system overview ...]
> E91 [system overview ...]
> E93 [system overview ...]
> R55 [system overview ...]
> R56 [System overview ...]
NOTE: The description applies to vehicles with "High" equipment level.
Depending on the vehicle's equipment specification, not all of the aerials described here may be fitted. Attention will be drawn to differences due to certain equipment combinations or national versions.
In principle, radio services can be separated into terrestrial services and satellite services. Terrestrial radio services are broadcast via ground aerials (stationary aerials for terrestrial reception).
Terrestrial services include:
- AM-FM radio transmitters (analogue)
- DVB-T (Digital Video Broadcasting - Terrestrial)
- TV transmitters (analogue)
- DAB (Digital Audio Broadcasting). DAB makes digital radio reception possible.
- GSM dual band 900/1800 MHz (for mobile phones)
Satellite services include:
- GPS (signals for navigation)
- SDARS (Satellite Digital Audio Radio Service, US version only)
Aerials for vehicle systems (the aerials themselves are not dealt with in this SBT):
- Aerials for remote control or Comfort Access
- Bluetooth aerial for connecting mobile phones to the vehicle
Most aerials are integrated in the rod aerial, roof-mounted aerial, side window and in the rear window.
> E93
The E93 (Convertible) has no visible aerials apart from the SDARS aerial (US version) on the tailgate.
Different aerials are used for radio reception depending on the position of the convertible hardtop (closed or open).
Convertible hardtop closed:
- Radio reception using aerials (AM, FM 1, FM 3) in the rear window
Convertible hardtop open:
- Radio reception using aerials (AM, FM 1) in the rear left side trim and the aerial (FM 3) in the rear right side trim
Brief description of components
The aerials supply signals for the aerial system:
- FM aerial
The FM aerial receives radio stations and traffic information in the FM (VHF) range (FM stands for "Frequency modulation"). The number of FM aerials installed in the aerial system varies:
> E81,E87,E93
4 FM aerials (FM 1, FM 2, FM 3, FM 4)
> E70, E71, E82, E88, E90, E91, E92, plus R55, R56
3 FM aerials: (FM 1, FM 2, FM 3)
For space-saving reasons, the FM 4 aerial does not exist physically. The FM 4 aerial is formed from the HF signal of the FM 1 and FM 2 aerials by way of heterodyning. This improves FM reception.
- AM aerial
The AM aerial receives radio stations in the SW, MW and LW ranges (SW stands for "short wave"; MW stands for "medium wave and LW stands for "long wave").
- TV aerial
The TV aerials receive analogue or digital television signals.
- DAB aerials (Europe version)
The DAB aerials picks up high-frequency signals (digital signals) from the radio transmitters (DAB: Digital Audio Broadcasting).
Different DAB aerials are used for radio reception:
- DAB L aerial (frequency range: L-band)
The DAB aerial is used for reception in urban areas.
- DAB III aerial (frequency range: III-band)
The DAB aerial is used for regional reception.
- GPS aerial
The GPS aerial picks up navigation signals transmitted by GPS satellites (GPS:. Global Positioning System).
- Telephone aerial
The telephone aerial is designed for the GSM mobile communication network and for other services, e.g. CDMA. (GSM stands for "Global Standard for Mobile Communication"; CDMA stands for "Code Division Multiplex Access")
- Emergency GSM aerial
The emergency GSM aerial is installed in vehicles with TCU (TCU stands for "Telematics Control Unit")
An emergency call can be transmitted through the emergency GSM aerial if the external telephone aerial is not working, because of an accident, for example.
[more ...]
- SDARS aerial (US version)
> E70, E71, E82, E88, E90, E91, E92, E93 plus R55, R56
High-frequency signals (digital signals) from satellites and stationary aerials for terrestrial reception are picked up by an SDARS aerial on the vehicle. (SDARS stands for "Satellite Digital Audio Radio Service")
An aerial cable routes the signals to the satellite tuner. [for more information, please refer to SI Technology (SBT) 65 03 03 058]
- VICS aerial (Japan version)
Information relating to the current road traffic situation is acquired from several locations and transferred to the VICS control centre. (VICS stands for "Vehicle Information and Communication System")
Information is provided by radio and infrared transmission for the current stretch of road. Information is provided both in text and graphic form.
> E70, E71
The E70, E71 has 2 aerials.
One aerial is integrated in the interior mirror, the other in the rear window.
> E81, E82, E87, E90, E91, E92
The aerial is integrated in the interior rear-view mirror.
> E88, E93
The aerial is installed in the mirror base of the inside mirror.
> R55
The R55 has 2 aerials.
One aerial is integrated in the interior mirror, the other in the rear left side window.
> R56
The R56 has 2 aerials.
One aerial is integrated in the interior mirror, the other in the rear window.
The individual aerials are integrated in the aerial system as follows:
- Aerials in rod aerial
> E81,E87
The rod aerial contains the aerials for AM, FM 1, telephone, GPS and DAB (frequency range: L-band).
> E88
The rod aerial contains the aerials for AM, FM 1 and telephone.
> R55, R56
Depending on the vehicle's equipment specification, up to 6 different equipment versions are possible. [more ...]
- Aerials in the roof-mounted aerial
> E70, E71, E82, E90, E91, E92
The following roof-mounted aerials are fitted:
- Roof-mounted aerials with aerials for telephone, GPS and DAB (Europe version).
- Roof-mounted aerial with telephone, telephone 2, GPS and SDARS (US version)
The US version of the roof-mounted aerial is noticeably larger than the Europe version. Depending on the vehicle's equipment specification, up to 5 different equipment versions are possible. [more ...]
- Aerial in the rear window
> E70, E71, E82, E87, E90, E91, E92, E93, R56
Conductors pressed onto the heated area of the rear window act as aerials. The heated area connections for the heated rear window are decoupled from the aerials by rejector circuits. [more ...]
- Aerials in side window
> E70
The television aerial (TV 2) is integrated into the rear right side window.
The following aerials are integrated into the rear left side window:
- TV aerial (TV 1)
- DAB aerial (frequency range: III-band) [more ...]
> E91
The television aerial (TV 2) is integrated into the rear right side window.
The television aerial (TV 1) is integrated into the rear left side window. [more ...]
> R55
The television aerial (TV 2) is integrated into the rear right side window.
The following aerials are integrated into the rear left side window:
- TV aerial (TV 1)
- DAB aerial (frequency range: III-band)
- FM aerial (FM 2)
- FM aerial (FM 3)
- VICS aerial (VICS 2) for Japan navigation system
> R56 in Japan national version
One TV aerial is integrated in the rear left and rear right side window. The TV aerials (TV 3 on the left in the direction of travel; TV 4 on the right in the direction of travel) have their own TV aerial amplifier. The aerial amplifier sends the signals from the 2 TV aerials to the control unit for the Japan navigation system.
- Aerial on tailgate
The aerial on the tailgate is of a similar design to the roof aerial, but it is much flatter.
> E88 Europe version
DAB aerial (frequency range: L-band)
> E88, E93 US version
SDARS aerial
- Aerials in the rear left and rear right side trims
> E93
When the convertible hardtop is open, radio stations are received using the aerials in the rear right and rear left side trims.
The following aerials are fitted in the rear left and rear right side trims:
- AM and FM aerial (FM 1)
- FM aerial (FM 3) [more ...]
- Aerials under the rear bumper trim
The following aerials are installed under the rear bumper trim:
> E71
- TV aerial (TV 2):
under the rear left bumper trim
- TV aerial (TV 3):
under the rear right bumper trim [more ...]
> E81,E87
- Telephone aerial (GSM 1): under the rear left bumper trim
> E88
- FM aerial (FM 2)
under the rear centre bumper trim
- FM aerial (FM 3):
under the rear left bumper trim
- Telephone aerial (GSM 2) for telematic services:
under the rear left bumper trim
- DAB aerial (frequency range: III-band)
under the rear right bumper trim [more]
> E93
- FM aerial (FM 4):
under the rear left bumper trim
- TV aerial (TV 1):
under the rear left bumper trim
- GSM aerial (GSM 2):
under the rear left bumper trim
- FM aerial (FM 2):
under the rear centre bumper trim
- DAB aerial (DAB III):
under the rear right bumper trim
- TV aerial (TV 2):
under the rear right bumper trim[more ...]
- Aerial behind the front left wheel arch cover
> E93
The telephone aerial is fitted behind the front left wheel arch cover. The telephone aerial (GSM 1) is directly connected to the eject box.
- Aerials in cowl panel
> E93
- DAB aerial (frequency range: L-band)
- GPS aerial
- Aerials in the folding top compartment lid
> E88
The GPS aerial is installed from the folding top compartment lid, left.
The following components are involved in operation of the aerial system:
- Aerial amplifier with aerial diversity for FM
The aerial amplifier compensates for losses that occur in the aerial line. The aerial diversity function makes available the signal from the aerial with the best reception to the radio.
> E81,E87
The aerial amplifier for the FM aerial (FM 1) and for AM aerial is located in the base of the rod aerial.
The aerial amplifier with aerial diversity for the FM 2 to FM 4 aerials is installed on the inside of the boot lid the rear window in the area of the auxiliary brake light.
NOTE: From 03/2008, aerial diversity is discontinued on the E81, E87 with BMW Audio radio (basic version).
From 03/2008, aerial diversity is discontinued on the E81, E87 with BMW Audio radio (basic version) The combination BMW Audio radio (basic version) and aerial diversity is only possible in conjunction with option 676 "HiFi loudspeaker system".
> E88
The aerial amplifier for the FM aerial (FM 1) and for AM aerial is located in the base of the rod aerial.
The aerial amplifiers for the FM aerials (FM 2, FM 3) are integrated in the aerial amplifier with aerial diversity. The aerial amplifier with aerial diversity is at the rear left in the luggage compartment.
> E70, E71, E82, E90, E91, E92
The aerial amplifier with aerial diversity is installed in the rear window in the area of the auxiliary brake light.
Other aerial amplifiers are also housed in the AM/FM aerial amplifier housing:
- Aerial amplifier for television aerial
> E82: TV function cannot be ordered as special equipment.
- Aerial amplifier for DAB (Digital Audio Broadcasting)
Moreover, the remote control receiver for unlocking the vehicle is also integrated into the module.
> E93
The aerial amplifier with aerial diversity is at the rear left in the luggage compartment.
The following aerial amplifiers are fitted in the aerial amplifier housing:
- Aerial amplifier for FM aerial (FM 2)
- Aerial amplifier for FM aerial (FM 4)
> R55
The aerial amplifier with aerial diversity is installed at the top of the left-hand C-pillar. Other aerial amplifiers are also housed in the AM/FM aerial amplifier housing:
- Aerial amplifier for TV aerial (TV 2)
- Aerial amplifier for DAB (Digital Audio Broadcasting)
> R56
The aerial amplifier with aerial diversity is located on the inside of the tailgate, under the rear window (between the rear window wiper and the C-pillar). Other aerial amplifiers are also housed in the AM/FM aerial amplifier housing:
- Aerial amplifier for TV aerials (TV 1 and TV 2)
- Aerial amplifier for DAB (Digital Audio Broadcasting) [more ...]
- Compensator
The compensator equalises losses in the telephone aerial wire. The compensator can be retrofitted at the customer's express wish to improve reception. [more ...]
- Suppressor filter
The suppressor filter suppresses interference from the rear window aerials in the additional brake light wires. Filter circuits in the interference suppression filter are designed to suppress conducted interference. The interference suppression filter is located in the positive and earth cable of the auxiliary brake light.
> E81, E87
No interference suppressor fitted (suppression filter not needed).
> E91
The interference suppression filter is additionally installed in the positive and earth wires for the heated rear window.
- Rejector circuit for heated rear window
The current to the conductors in the rear window is fed through 2 rejector circuits. The rejector circuits act as throttles to reduce the transmission of interference pulses in the aerials from the vehicle electrical system.
A rejector circuit is integrated into the earth wire on the left-hand side of the rear window. An identical rejector circuit is integrated into the positive (+) wire on the right-hand side of the rear window.
> E70
The rejector circuit is installed at the top of the left-hand C-pillar.
> E71
The rejector circuits are located in the tailgate above the rear window.
> E81, E87
The rejector circuits are located in the tailgate under the rear window.
> E82, E90, E92, E93
The rejector circuits are located on the left and right-hand sides under the C-pillar trim.
> E91
The rejector circuits are integrated in the interference suppression filter.
> R55
A rejector circuit is located in each split door, above the rear window.
> R56
The rejector circuits are located in the tailgate under the rear window.
- TV aerial amplifier
Each television aerial is connected to a TV aerial amplifier. The TV aerial amplifier compensates for losses that occur in the aerial line. The TV aerial amplifiers are powered remotely by the video module.
> E70
3 TV aerial amplifiers are connected to the video module.
> E71
The TV aerial amplifier for TV 1 is integrated in the aerial amplifier for AM and FM. The TV aerial amplifier for TV 2 and TV 3 are connected directly to the video module.
> E81, E82, E87
No TV
> E90, E92
The TV aerial amplifiers are integrated in the AM and FM aerial amplifiers.
> E91
2 TV aerial amplifiers are connected to the video module.
The TV aerial amplifiers are installed in the left and right C-pillars at the level of the rear side windows.
> E93
2 TV aerial amplifiers are connected to the video module.
The TV aerial amplifiers are under the rear bumper trim.
> R55
The TV aerial amplifier for TV 2 is integrated in the aerial amplifier for AM and FM. The TV aerial amplifier for TV 1 is installed at the right-hand C-pillar. The TV aerial amplifiers are connected to the video module.
> R56
The TV aerial amplifiers are integrated in the AM and FM aerial amplifiers.
(In the Japan version, the R56 has a separate TV aerial amplifier for the aerials TV 3 and TV 4)
- Coaxial cable
The coaxial cables carry high-frequency signals, e.g. between the aerial amplifier and the radio.
- RAD_ON wire
The RAD_ON wire carries the "Radio on" signal. The RAD_ON wire switches on the aerial amplifier with aerial diversity and the AM/FM aerials.
- aerial splitter
>11GE87
Until 09/2007, only one telephone aerial was installed. An aerial splitter divided the aerial output between the TCU and the mobile phone.
From 09/2007, 2 telephone aerials are fitted. It is no longer necessary to divide the aerial output. The aerial splitter is thus discontinued.
The following control units are involved in the aerial system:
- Radio, M-ASK, CHAMP or CCC
- BMW "Audio" radio, BMW "Business CD" radio, BMW "Professional" radio
A MOST bus is fitted for the BMW "Professional" radio and higher. [for more information, please refer to SI Technology (SBT) 65 06 04 101]
- M-ASK or CHAMP: Multi-audio system controller or multimedia platform The M-ASK is fitted with option "Business Navigation". The menus are displayed on the Central Information Display (CID).
In the US version, the Central Headset and Multimedia Platform (CHAMP) is operated as the BMW Professional radio instead of M-ASK. In contrast to M-ASK, CHAMP does not have a navigation system.
[for more information, please refer to SI Technology (SBT) 84 01 03 004 ]
- CCC: Car Communication Computer
The CCC controls all information and communication systems. The menus are displayed on the Central Information Display (CID).
[for more information, please refer to SI Technology (SBT) 84 06 03 053 ]
- TCU: Telematics control unit
A transmitter/receiver module (transceiver) with its own SIM card is installed in the TCU (SIM stands for "Subscriber Identity Module"). [for more information, please refer to SI Technology (SBT) 84 01 04 118]
- VM: Video module
The video module is the central receiver unit for the picture signals from the TV aerials. In addition, the video module is a selector switch for the video sources. All TV aerial amplifiers are powered remotely by the video module.
[for more information, please refer to SI Technology (SBT) 65 07 04 105 ]
- VM Hybrid: Hybrid video module (as from 03/2005 Europe version)
The hybrid video module is a combination of the video module (for analogue TV reception) and the set-top box (for digital TV reception).
- IBOC: Digital tuner US (US version only)
> E90, E91 as from 09/2005
> E70, E71, E82, E88, E92, E93
> R55, R56
IBOC is an FM tuner that can receive additional digital information (IBOC stands for "In-Band On-Channel").
IBOC performs the task of the conventional tuner. This means the tuner function of the conventional tuner is coded inactive.
- DAB: Digital tuner (not US version)
DAB (Digital Audio Broadcasting) makes digital radio reception possible. The digital tuner converts the digital signals from the DAB aerials into optical signals (light signals). The digital tuner transmits these optical signals on the MOST bus.
- SDARS: Satellite tuner (US version only)
SDARS (Satellite Digital Audio Radio Service) facilitates digital radio reception via satellite and terrestrial reception via stationary aerials
[for more information, please refer to SI Technology (SBT) 65 03 03 058 ]
System functions
The following aerial system functions are described:
- Aerial diversity for FM aerials
- Diagnosis function for aerial diversity
Aerial diversity for FM aerials
To ensure the best possible reception, aerial diversity works as follows:
- One of the aerials (FM 1) receives the required radio station.
- If the signal from this aerial deteriorates, the system switches to one of the other aerials (FM 2, FM 3, FM 4) with a stronger signal.
> E93
Depending on the position of the convertible hardtop (closed or open), aerial diversity will switch to either the aerials in the rear window or the aerials in the rear left and rear right side trim for radio reception.
The Convertible Top Module (CTM) records the position of the convertible hardtop. The CTM transmits a signal through a direct wire to aerial diversity.
Diagnosis function for aerial diversity
Aerial diversity self-diagnosis comprises a check of the aerial inputs based on DC current measurement. In diagnosis mode, the AM/FM tuner switches each FM aerial on individually in turn.
AM reception can be evaluated with the AM amplifier switched on and off. A comparison of the results will produce the diagnosis output.
Notes for service staff
The following information is available for service staff:
- General notes: [more ...]
- Diagnosis: [more ...]
- Encoding/programming: --
National versions
The following details are available with regard to national versions:
- Japan version
Navigation system with VICS: Vehicle Information and Communication System
Current highway traffic data are displayed to the driver in the navigation system. Information is gathered from various sources and transmitted to the central VICS module:
- Highway management
- Police
- Highway traffic information centre
Information is provided by radio and infrared transmission for the current stretch of road. In urban areas, information is also displayed on display boards. In this way, delays are reduced and other information is displayed such as accident locations, construction sites and free parking spaces.
- US version
Depending on the vehicle's equipment, an aerial splitter may be fitted. The aerial splitter divides the high-frequency (HF) signals received from the aerial amplifier with aerial diversity between the IBOC and the headset. This division allows the headset to receive Real Time Traffic Information (RTTI) data.