There are several different operational modes. Modes have different states controlled by
the cellular SW. Some examples are: Idle State (on ACCH), Camping (on DCCH), Scanning,
Conversation, No Service Power Save (NSPS) previously OOR = Out of Range.
In the power off mode, only the circuits needed for power up are supplied.
In the idle mode, circuits are powered down and only the sleep clock is running.
In the active mode, all the circuits are supplied with power although some parts might
be in idle state part of the time.
The charge mode is effective in parallel with all previous modes. The charge mode itself
consists of two different states (i.e., the fast charge and the maintenance mode).
The core parts of 3560/3520 BB consists of two ASICs—UEM and UPP—and flash memory. The following sections describe these parts.
PA Supply
RF Supplies
RF RX/TX
EAR
MIC
LM4890
VIBRA
M
Battery
UEM
XEAR
DCT4 Janette connector
External Audio
Charger con n ec tion
Baseband
DLIGHT
KLIGHT
SLEEPCLK
32kHz
CBUS/
DBUS
Supplies
MBus/FBus
UI
19.44MHz
Safari
RFBUS
UPP
MEMADDA
FLASH
UEM
UEM introduction
The UEM is the Universal Energy Management IC for DCT4 digital handportable phones.
In addition to energy management, it performs all the baseband mixed-signal functions.
Most UEM pins have 2kV ESD protection and those signals which are considered to be
exposed more easily to ESD have 8kV protection inside UEM. Such signals are all audio
signals, headset signals, BSI, Btemp, Fbus, and Mbus signals.
Regulators
The UEM has six regulators for BB power supplies and seven regulators for RF power supplies. The VR1 regulator has two outputs (VR1a and VR1b). In addition, there are two
current generators (IPA1 and IPA2) for biasing purposes.
A bypass capacitor (1uF) is required for each regulator output to ensure stability.
Reference voltages for regulators require external 1uF capacitors. Vref25RF is reference
voltage for VR2 regulator, Vref25BB is reference voltage for VANA, VFLASH1, VFLASH2,
VR1 regulators, Vref278 is reference voltage for VR3, VR4, VR5, VR6, VR7 regulators,
VrefRF01 is reference voltage for VIO, VCORE, VSIM regulators, and for RF.
BBRFCurrent
VANA: 2.78Vtyp 80mAmaxVR1a:4.75V 10mAmax
VR1b:4.75V
Vflash1: 2.78Vtyp 70mAmaxIPA2: 0-5mA
Vflash2: 2.78Vtyp
40mAmax
VSim: 1.8/3.0V 25mAmaxVR3:2.78V 20mA
VIO: 1.8Vtyp
150mAmax
Vcore: 1.0-1.8V
200mAmax
VR2:2.78V 100mAmax
VR4: 2.78V 50mAmax
VR5: 2.78V 50mAmax
VR6: 2.78V 50mAmax
VR7: 2.78V 45mAmax
IPA1: 0-5mA
VANA regulator supplies internal and external analog circuitry of BB. It is disabled in
sleep mode.
Vflash1 regulator supplies LCD, IR-module and digital parts of UEM and Safari asic. It is
enabled during startup and goes to low Iq-mode in sleep mode.
Vflash2 regulator is not used.
VIO regulator supplies both external and internal logic circuitries. It's used by LCD, flash,
and UPP. Regulator goes in to low Iq-mode in sleep mode.
VCORE regulator supplies DSP and Core part of UPP. Voltage is programmable and the
start-up default is 1.5V. Regulator goes to low Iq-mode in sleep mode.
VSIM regulator is not used.
VR1 regulator uses two LDOs and a charge pump. Charge pump requires one external 1uF
capacitor in Vpump pin and 220nF flying capacitor between pins CCP and CCN. VR1 regulator is used by Safari RF ASIC.
VR2 regulator is used to supply external RF parts, lower band up converter, TX power
detector module, and Safari. In light load situations, VR2 regulator can be set to low
Iq-mode.
VR3 regulator supplies VCTCXO and Safari in RF. It's always enabled when UEM is active.
When UEM is in sleep mode, VR3 is disabled.
VR4 regulator supplies RF parts having low noise requirements. In light load situations,
VR4 regulator can be set to low Iq-mode.
VR5 regulator supplies lower band PA. In light load situations, VR5 regulator can be set
to low Iq-mode.
VR6 regulator supplies higher band PA and TX amplifier. In light load situations, VR6 regulator can be set to low Iq-mode.
VR7 regulator supplies VCO and Safari. In light load situations, the VR7 regulator can be
set to low Iq-mode.
IPA1 and IPA2 are programmable current generators. 27kW/1%/100ppm external resistor
is used to improve the accuracy of output current. IPA1 is used by lower band PA and
IPA2 is used by higher band PA.
RF Interface
The interface between the baseband and the RF section also is handled by UEM. It provides A/D and D/A conversion of the in-phase and quadrature receive and transmit signal
paths and also A/D and D/A conversions of received and transmitted audio signals to and
from the UI section. The UEM supplies the analog AFC signal to RF section according to
the UPP DSP digital control. It also converts PA & VCTCXO temperature into real data for
the DSP.
Charging Control
The CHACON block of UEM asics controls charging. Needed functions for charging controls are pwm-controlled battery charging switch, charger-monitoring circuitry, and battery voltage monitoring circuitry. In addition, external components are needed for EMC
protection of the charger input to the baseband module. The DCT4 baseband is designed
to support both DCT3 and DCT4 chargers from an electrical point of view.
Digital Interface
Data transmission between the UEM and the UPP is implemented using two serial connections, DBUS (programmable clock) for DSP and CBUS (1.0MHz GSM and 1.08MHz
TDMA) for MCU. UEM is a dual voltage circuit, the digital parts are running from 1.8V
and the analog parts are running from 2.78V. Vbat (3,6V) voltage regulator inputs also
are used.
Audio Codec
The baseband supports two external microphone inputs and one external earphone output. The inputs can be taken from an internal microphone, from a headset microphone,
or from an external microphone signal source through headset connector. The output for
the internal earpiece is a dual-ended type output, and the differential output is capable
of driving 4Vpp to the earpiece with a 60 dB minimum signal to total distortion ratio.
Input and output signal source selection and gain control is performed inside the UEM
Asic according to control messages from the UPP. The buzzer and an external vibra alert
control signals are generated by the UEM with separate PWM outputs.
There are discrete drivers for the MIDI speaker and keyboard LEDs. The drivers for vibra
and display are inside UEM.
AD Converters
There is an 11-channel analog-to-digital converter in UEM. The AD converters are calibrated in the production line.
UPP8M
RH-14 uses UPP8M ASIC. The RAM size is 8M. The UPP ASIC is designed to operate in a
DCT4 engine. The UPP processor architecture consists of both DSP and MCU processors.
Blocks
UPP is internally partitioned into two main parts:
The Processor and Memory System (i.e., Processor cores, Mega-cells, internal memories, peripherals, and external memory interface). This is known as the Brain.
The Brain consists of the blocks: the DSP Subsystem (DSPSS), the MCU Subsystem
(MCUSS), the emulation control (EMUCtl), the program/data RAM (PDRAM) and the
Brain Peripherals–subsystem (BrainPer).
The NMP custom cellular logic functions. This is known as the Body.
The Body contains all interfaces and functions needed for interfacing other DCT4 baseband and RF parts. Body consists of following sub-blocks: MFI, SCU, CTSI, RxModem,
AccIF, UIF, Coder, GPRSCip, BodyIF, SIMIF, PUP, and CDMA (Corona).
Flash Memory
Introduction
The RH-14 tranceivers use a 64-Mbit flash as its external memory. The VIO regulator is
used as a power supply for normal in-system operation. An accelerated program/erase
operation can be obtained by supplying Vpp of 12 volt to the flash device.
The device has two read modes: asynchronous and burst. The Burst read mode is utilized
in RH-14, except for the start-up, when the asynchronous read mode is used for a short
time.
In order to reduce the power consumpition on the bus, a Power Save function is introduced. This reduces the amount of switching on the external bus.
User Interface Hardware
LCD
Introduction
RH-14 uses a color GD51 96 x 65 full dot-matrix graphical display. The LCD module
includes LCD glass, LCD COG-driver, spring connector, and metal frame. The LCD module
is included with the lightguide assembly module.
Interface
SW and the control signals are from the UPP asic. The VIO and Vflash1 regulators supply
the LCD with power. The LCD has an internal voltage booster and a booster capacitor is
required between Vout and GND.
Pin 3 (Vss) is the LCD driver's ground. LCD is controlled by UI SW and control signals.
Booster capacitor (C302 1 uF) is connected between booster pin (Vout) and ground. The
capacitor stores boosting voltage.
Keyboard
Introduction
The RH-14 keyboard follows the Jack III style.
PWR key is located on top of phone.
Power Key
All keyboard signals come from UPP asic, except pwr key signal, which is connected
directly to UEM. Pressing of pwr key is detected so that switch of pwr key connects
PWONX is of UEM to GND and creates an interrupt.
Lights
Introduction
RH-14 has LEDs for lighting purposes: two LEDs for keyboard and two LEDs for display.
LED type is TBSF (white).
Interfaces
Both the display and keyboard lights are controlled through a shared LED driver with a
constant current charge-pump circuit. The driver circuit is controlled by the Dlight signal
from UEM. With appropriate SW, the driver can be PWM controlled for dimming purpose.
Technical Information
LED locates in hole and terminals are soldered on the component side of the module
PWB. The LEDs have a white plastic body around the diode, and this directs the emitted
light better to the UI-side.
The current for the LCD lights is limited by the resistor between the ISET pin of the LED
driver and ground. For the keyboard lights, there are resistors in parallel.
The vibra is located on D-cover and is connected by spring connectors on PWB. It is
located in the left bottom side of the engine.
Interfaces
The vibra is controlled by the PWM signal VIBRA from the UEM. With this signal, it is
possible to control both the frequency and pulse width of signal. Pulse width is used to
control current when the battery voltage changes. Frequency control makes it possible to
search for an optimum frequency to provide silent and efficient vibrating.
Audio Hardware
Earpiece
Introduction
The 13 mm speaker capsule that is used in DCT3 products is also used in RH-14.
The speaker is dynamic. It is very sensitive and capable of producing relatively high sound
pressure at low frequencies.
Microphone
Introduction
The microphone is an electret microphone with an omnidirectional polar pattern. It consists of an electrically polarized membrane and a metal electrode which forms a capacitor. Air pressure changes (i.e., sound) move the membrane, which cause voltage changes
across the capacitor. Becauce the capacitance is typically 2 pF, a FET buffer is needed
inside the microphone capsule for the signal generated by the capacitor. Because of the
FET, the microphone requires a bias voltage.
MIDI Speaker
Introduction
The speaker being used to generate MIDI ring tones is a 13mm SALT speaker. The SALT
speaker is mounted in the D-cover, kept in position by a double adhesive gasket that is
mounted on the front of SALT. The useful frquency range is approximately 340 Hz to
8KHz.
Battery
Phone Battery
Introduction
The battery for the 3560/3520 is the BLC-2 (Li-Ion 1000 mAh).
The battery block contains BTEMP and BSI resistors for temperature measurement and
battery identification. The BSI fixed resistor value indicates the chemistry and default
capacity of a battery. BTEMP-resistor measures the battery temperature. Temperature
and capacity information is needed for charge control. These resistors are connected to
BSI and BTEMP pins of the battery connector. Phone has pull-up resistors (R202) for
these lines so that they can be read by A/D inputs in the phone (see figure below). There
also are spark gaps in the BSI and BTEMP lines to prevent ESD.
Figure 3: Battery Connections.
Batteries have a specific red line which indicates if the battery has been subjected to
excess humidity. The batteries are delivered in a "protection" mode, which gives longer
storage time. The voltage seen in the outer terminals is zero (or floating), and the battery
is activated by connecting the charger. Battery has internal protection for overvoltage
and overcurrent.
RH-14 uses DCT4-accessories via DCT4 system connector.
Interface
The interface is supported by DCT4-compatible, fully differential 4-wire (XMICN, XMICP,
XEARN, and XEARP) accessories.
Figure 5: System Connector.
An accessory is detected by the HeadInt- line, which is connected to the XMIC. When
accessory is connected, it generates headint- interruption (UEMINT) to MCU. After that,
hookInt line is used to determine which accessory is connected. This is done by the voltage divider, which consists of phone's internal pull-up and accessory specific pull-down.
Voltage generated by this divider is then read by the ad- converter of UEM. The HookIntinterrupt is generated by the button in the headset or by the accessory external audio
input.
ESD protection is made by spark gaps, buried capacitor and inside UEM, which is protected ±8 kV. RF and BB noise is prevented by inductors.
Charger IF
Introduction
The charger connection is implemented through the bottom connector. DCT-4 bottom
connector supports charging with both plug chargers and desktop stand chargers.
2.1V
33N
0.8V
Figure 6: Accessory Detection / External Audio.
2k2
1.8V
0.3V
There are three signals for charging. Charger gnd pin is used for both desktop and for
plug chargers as well as charger voltage. PWM control line, which is needed for 3-wire
chargers, is connected directly to gnd in module PWB so the engine doesn't provide any
PWM control to chargers. Charging controlling is done inside UEM by switching UEM
internal charger switch on/off.
Interface
The fuse F100 protects the phone from currents that are too high (for example, when
broken or pirate chargers are used). L100 protects engine from RF noise, which may
occur in charging cable. V100 also protects the UEM asic from reverse polarity charging
voltage and from excessive charging voltage. C105 is also used for ESD and EMC protection. Spark gaps are used for ESD protection right after the charger plug.
Interface for RH-14 production testing is 5-pin pad layout in BB area (see figure below).
Production tester connects to these pads by using spring connectors. Interface includes
MBUS, FBUSRX, FBUSTX, VPP and GND signals. Same pads also are used for AS test
equipments such as module jig and service cable.
Other Test Points
Because BB asics and flash memory are CSP components, the access to BB signals is very
poor. This makes measuring of most of the BB signals impossible. In order to debug BB at
least on some level, the most important signals can be accessed from 0.6 mm test points.
EMC
General
There are many ways to protect the phone from EMC. One form of protecting BB against
EMC is a shield to cover main components of BB — components such as UEM, UPP and
Flash. UEM has internal protection against ±8kV ESD pulse. BB shield has a removable lid
so repairing of BB is possible. Shield also improves thermal dissipation by spreading the
heat more widely.
7.
MBUS
3.
FBUS_R X
8.
GND
2.
FBUS_TX
6.
VPP
Figure 7: Top View of Production Test Pattern
BB Component and Control IO Line Protection
Keyboard lines
The keyboard PWB layout consists of a grounded outer ring and either a "trefoil pattern"
grid (matrix) or an inner pad. This construction makes the keys immune for ESD, as the
keydome will have a low ohmic contact with the PWB ground.
The keyboard is controlled entirely by the UPP. The rows and columns are ESD protected
by diodes and spark gaps.
PWB
The PWB has been designed to shield all lines susceptible for radiation. Sensitive PWB
tracks have been drawn with respect to shielding by having ground plane over tracks,
and ground close to the tracks at the same layer.
All edges are grounded from both sides of PWB and solder mask is opened from these
areas. Target is that any ESD pulse faces ground area when entering the phone; for
example, between mechanics covers. All holes in PWB are grounded and plated through
holes.
LCD
ESD protection for LCD is implemented by connecting metal frame of LCD in to gnd. Connection is only on one side, at the top of the LCD.
Microphone
Microphone signals are input lines and therefore very sensitive to radiated fields. Immunity for radiated fields is done to obtain a low impedance path and with respect to a
common noise point of view in the signal path. This is applied for both internal and
external microphone lines. Microphone is an unsymmetrical circuit, which makes it well
protected against EMC.
EAR Lines/MIDI
Internal EAR lines are EMC/ESD protected by radiated fields from the earpiece by the low
impedance signal path in the PWB.
The same PWB outline has been implemented for the SALT speaker. Low ohm coils are
used in series with the speaker for immunity against incoming fields from the speaker.
System Connector Lines
System Connector signals that have EMC protection
Protection typeVINXMIXPXMICNXEARPXEARNHEADINTMICP
ferrite bead (600
/199MHz)
ferrite bead (420
/100MHz)
spark gapsXXXXXX
PWB capacitorsXXXXXX
RC-circuitXXXXX
X
XXXXX
capacitor to
ground
XXXXX
HF and HFCM lines have spark gaps, and a ferrite bead RF filter (450 W/100 MHz).
Headint and Hookint have spark gaps as well as an RC-circuit.
Charger + is protected with a ferrite bead (42 W/100 MHz) and capacitor to ground (1 n).
RFCLK & GNDSee BB_RF IF Conn / RFCLK (not BUS …)
RFICCNTRL(2:0)See BB_RF IF Conn / RFICCNTRL(2:0)
GENIO(28:0)/rips 5 and 6See BB_RF IF Conn / GENIO(28:0) also Sec 5.2.4
Signal
Name
#
DAMPS/
UPP Globals, no bus, no ripPower supplies and GND
VIOUPPUEM
VCOREUPPUEM
GNDUPPVSSXX X0Global GND
Connected
from --- to
UPP
I/O
In
In
Signal Properties
A/D--Levels---Freq./
Timing resolution
1.8 V
+- 4.5 %
+- 5 %
20mA max. UPP I/O power supply
100mA
max.
Description / Notes
UPP logics and processors power supply,
settable to reach the speed for various cloc
frequencies.
System ConnectorHP Internal microphone IF between system connector and Mic/Ear circuitry
XMICPHS/HF
XMICNInAna100mV nom
Connected
from - to
SysCo
n/
HeadSet
Con
Mic
UEMOutAna200mVpp
UEMOutAna
Audio
- UEM
AUDIO
I/O
In
Out
Signal Properties
A/D Levels-Freq./
Timing resolution
AudioDifferential signal from
max diff
0...2.7 VDCHS Button interrupt, Exter-
/Dig
Ana
Bias
100mV nom
diff
2.1V bias
1kohm
diff ; 2.1V
bias 1k ohm
Audio
DC bias
Audio
Description / Notes
external MIC
nal Audio Accessory Detect
(EAD)
Differential symmetric
input.
Accessory detection by bias
loading (EAD channel of
slow ADC of UEM)
Hook interrupt by heavy
bias loading
XEARPHS/HF
XEARN
Signal
RIP
name
LCDUI(2:0)Display & UI Serial Interface
0LCDCAMCLKUPPDisplInDig0/1.8V1 MHzClock to LCD
1LCD-
CAMTXD
2LCDCSXUPPDisplInDig0/1.8VLCD Chip Select
GENIO(28:0)General I/O Pins
EAR/
Amp.
Connected
from - to
UPPDisplIn/
Audio
- UEM
InAna100 mV nom
diff
Display
I/O
Out
Signal Properties
A/D Levels-Freq./
Timing resolution
Dig0/1.8V1 MHzData to/from LCD
AudioQuasi differential DC-cou-
pled earpiece/HF amplifier
signal to accessory. DC
biased to 0.8V; XEARN a
quiet reference although
have signal when loaded
due to internal series resistor.
System ConnectorHP Internal microphone IF between System Connector and Mic/Ear circuitry
XMICPHS/HF
XMICNInAna100mV
XEARPHS/HF
XEARN
Connected
from - to
Audio
Mic
EAR/
Amp.
- UEMInOut
Audio
-UEM
Sys Conn
I/O
InAna100mV
Signal Properties
A/D Levels-Freq./
Timing resolution
Ana
100mV
Bias
nom
diff
2.1V
bias, 1K
ohm
nom
diff ;
2.1V
bias
1kohm
nom
diff
Description / Notes
Audio
DC bias
Audio
AudioQuasi differential DC-coupled
Differential symmetric output.
Accessory detection by bias
loadind.
Hook interrupt by heavy bias
loading..
earpiece/HF amplifier signal to
accessory. DC biased to 0.8V;
XEARN a quiet reference
although have signal when
loaded due to internal series
resistor.
INTSwitchAudio
- UEM
CHARGER INTERFACE
CHARGER lines, no bus *
VCHARINChargerUEMInVchr< 16V
GNDGN
CHRGCTRLInputOut-
put
Signal
RIP
name
GNDGlo-
VBATBatt +Vbatt3.0-4.2VDCBattery Voltage
Connected
from - to
Batt -Global GND
bally
InDig0/2.7VHS interrupt from system con-
nector switch when plug
inserted
DCVch from Charger Connector,
D
Batt Conn
I/O
<1.2A
32Hz,
0/2.8V
Signal Properties
A/D Levels-Freq./
Timing resolution
Note! Baseband doesn't wake up automatically when the battery voltage is connected (normal mode).
Power can be switched on by
•Pressing the power key
•Connecting a charger
•RC-alarm function
In the local and test mode, the baseband can be controlled through MBUS or FBUS
(FBUS is recommended) connections by Phoenix service software.
RF Module
Requirements
The RH-14 RF module supports the following systems:
AMPS
TDMA800
TDMA1900
Hence, the minimum transceiver performance requirements are described in TIA/EIA136-270. The RH-14 RF must follow the requirements in revision A. EMC requirements
are set by FCC 47CFR 15.107 (conducted emissions), 15.109 (radiated emissions, idle
mode), and 22.917 (radiated emissions, call mode) [1].
The dualband RF-module is capable of seamless operation between 800 MHz and
1900 MHz bands with measuring capability for cross-band hand-offs and maho-measurements.
Temperature Conditions
Temperature range:
ambient temperature: -30...+ 60 °C
PWB temperature: -30...+85 °C
storage temperature range: -40 to + 85 °C
All of the EIA/TIA-136-270A requirements are not exactly specified over temperature
range. For example, RX sensitivity requirement is 3 dB lower over –30..+60 °C range.
The RH-14frequency plan is shown in the following figure. A 19.44 MHz VCTCXO is used
for UHF and VHF PLLs and as a baseband clock signal. All RF locals are generated in PLLs.
The RX intermediate frequency is the same on both operating bands. Due to the AMPS
mode simultaneous reception and transmission, TX and RX IF frequencies are exactly
45 MHz apart from each other. RXIF is 135.54 MHz and TXIF 180.54MHz. The RXIF frequency is set so that it is not a multiple of either of the VHF's comparison frequency
(120 k). The digital-only operation on highband allows a free selection of the TX IF frequency, since separate TXIF filters are implemented. Hence, the highband TX IF frequency
is freely fixed to 181.8MHz due to the best possible spurious signal filtering. Therefore,
the UHF frequency needs to be changed according to TX and RX slots in TDMA1900 operation.
Note: The current values in the figure below are not absolute values and cannot be measured. These
values represent maximum/typical currents drawn by the corresponding RF or SAFARI blocks in use,
and are, therefore, dependent on the phone’s operating mode and state.
The regulator circuit is the UEM and the specifications can be found in the table below:
Regulator
name
VR1 a/b4.75 ± 3%1044
VR22.78 ± 3%10010076
VR32.78 ± 3%2022
VR42.78 ± 3%502324
VR52.78 ± 3%5055
VR62.78 ± 3%5055
VR72.78 ± 3%454045
IPA1, IPA22.7 max.1 ± 10%
VREFRF011.35 ± 0.5%0.120.050.05
VFLASH12.78 ± 3%7011
Output voltage (V)
Regulator Max.
current (mA)
3 ± 4%
3.5 ± 4%
5 ± 3%
RF total
1GHz
1.3 – 5.01.3 – 3.7
Receiver
The receiver shows a superheterodyne structure with zero 2nd IF. Lowband and highband
receivers have separate frontends from the diplexer to the first IF. Most of the receiver
functions are integrated in the RF ASIC. The only functions out of the chip are highband
LNA, duplexers, and SAW filters. In spite of a slightly different component selection, the
receiver characteristics are very similar on both bands.
RF total 2GHz
An active 1st downconverter sets naturally high gain requirements for preceding stages.
Hence, losses in very selective frontend filters are minimized down to the limits set by
filter technologies used and component sizes. LNA gain is set up to 16dB, which is close
to the maximum available stable gain from a single stage amplifier. LNAs are not exactly
noise matched in order to keep passband gain ripple in minimum. Filters have relative
tight stopband requirements, which are not all set by the system requirements but the
interference free operation in the field. In this receiver structure, linearity lies heavily on
mixer design. The 2nd order distortion requirements of the mixer are set by the 'half IF'
suppression. A fully balanced mixer topology is required. Additionally, the receiver 3rd
order IIP tends to depend on active mixer IIP3 linearity due to pretty high LNA gain.
The IF stages include a narrowband SAW filter on the 1st IF and a integrated lowpass filtering on zero IF. The SAW filter guarantees 14dBc attenuation at alternating channels,
which gives acceptable receiver IMD performance with only moderate VHF local phase
noise performance. The local signal's partition to receiver selectivity and IMD depends
then mainly on the spectral purity of the 1st local. Zero 2nd IF stages include most of
the receivers signal gain, AGC control range, and channel filtering.
The TDMA 1900 LNA is a discrete circuit. It uses an integrated Bias control block, which
is inside the SAFARI. In normal high-gain operation mode, the bias voltage 2.78 V is connected on collector and sink type constant current source is connected on emitter. Bias
current source is adjustable from 0.5 mA to 7.5 mA with 0.5 mA step. Base is biased from
2.78 V voltage via resistor.
dB
dB
When the LNA AGC step is enabled, LNA is in low gain operation mode. Voltage and current bias sources and direction of current are switched on the contrary. In this operation
mode, the LNA has good linearity, a low noise figure, and about -3 dB gain.
During the TX-slot, LNA is in power-down mode. This is executed by switching the bias
current source to 0 mA.
Max IF/2nd IF buffer output level3V pp (differential)
Frequency Synthesizers
RH-14 contains three synthesizers — one UHF synthesizer and two VHF synthesizers. The
UHF synthesizer is based on an integrated PLL and external UHF VCO, loop filter, and
VCTCXO. Its main goal is to achieve the channel selection for dual band operations associated with dual mode. Due to the RX and TX architecture, this UHF synthesizer is used
for down conversion of the received signal and for final up conversion in transmitter. A
common 2GHz UHFVCO module is used for operation on both low and highband. A frequency divider is integrated in the Safari.
Two VHF synthesizers consist of: RX VHF Synthesizer includes integrated PLL and VCO
and external loop filter and resonator. The output of RX-VHF PLL is used as LO signal for
the second mixer in receiver. TX VHF Synthesizer includes integrated PLL and external
amplifier, loop filter, and resonator. The output of TX-VHF PLL is used as a LO signal for
the IQ-modulator of the transmitter.
Transmitter
The transmitter RF architecture is an up-conversion type (desired RF spectrum is low side
injection) with (RF-) modulation and gain control at IF. The IF frequency is band related—
180.54 MHz in the cellular band and 181.80MHz in the PCS band. The cellular band is
from 824.01-848.97 MHz and the PCS band is from 1850.01-1909.95 MHz.
Common IF
The RF modulator is integrated with a PGA (Programmable Gain Amplifier) and IF output
buffer inside the SAFARI_T RFIC-chip (I- and Q-signals that are output signals from BBside SW IQ-modulator have some filtering inside Safari before RF-modulation is performed). The required LO-signal from the TXVCO is buffered with phase shifting in Safari.
After modulation (π/4 DQPSK or FM), the modulated IF signal is amplified in the PGA.
Cellular Band
When operating in cellular band, the IF signal is buffered at IF output stage that is
enabled by TXP1 TX control. The maximum linear (balanced) IF signal level to 50Ω load is
about –8 dBm.
For proper AMPS-mode receiver (duplex) sensitivity, IF signal is filtered in strip-filter
before up-conversion. The upconverter mixer is actually a mixer with LO and output
driver being able to deliver about +6 dBm linear output power. Note that in this point,
term linear means –33 dB ACP. The required LO power is about –6 dBm. The LO signal is
fed from Safari.
Prior to the power amplifier, the RF signal is filtered in a band-pass filter. The typical
insertion loss is about –2.7 dB, and maximum less than –3.5 dB. The input and output
return losses are approximately -10 dB.
The power amplifier is 50Ω/50Ω module. It does not have its own enable/disable control
signal, but it can be enabled by bias voltage and reference bias current signals. The gain
window is +27 to +31 dB and the linear output power is +30dBm (typical condition)
with –28 dB ACP. The nominal efficiency is 50 percent.
PCS Band
During operation in the PCS band, the IF signal is routed from the Safari to be filtered in
the TX IF SAW filter. The signal is returned to the Safari, and then routed to the up-converter mixer. The LO-signal to the mixer is buffered and balanced inside the Safari. The
mixer output is enabled by the TXP2 TX control signal. The maximum linear (balanced) RF
signal level to a 50Ω load is about +7 dBm.
After the Safari, the balanced RF-signal is single-ended in 1:1 balun and then filtered in
SAW filter. The typical insertion loss is about –4.0 dB, and maximum less than –5.7 dB.
This filter has a relatively high pass band ripple of about 1.0-1.5 dB, the largest insertion
being at the high end of the band. The input and return losses are about –10 dB.
Power amplifier is 50Ω/50Ω module. It does not have its own enable/disable control signal, but it can be enabled by bias voltage and reference bias current signals. The gain
window is +31 to +36 dB and linear output power is +30 dBm (typical condition) with
-28 dB ACP. The nominal efficiency is 40 percent.
Power Control
For power monitoring, there is a power detector module (PDM) built from a (dual)coupler, a biased diode detector, and an NTC resistor. RF signals from both bands are routed
via this PDM. The RF isolation between couplers is sufficient not to lose filtering performance given by duplex filters.
The diode output voltage and NTC voltage are routed to BB A/D converters for power
control purposes. The TX AGC SW takes samples from diode output voltage and compares
those values to target value, and adjusts BB I-and Q-signal amplitude and/or Safari PGA
settings to keep power control in balance.
NTC voltage is used for diode temperature compensation and for thermal shutdown
when radio board’s temperature exceeds +85° C.
False TX indication is based on detected power measurement when carrier is not on.
The insertion loss of coupler is –0.42 dB (max) at cellular band and –0.48 dB (max) at
PCS band. Typical values for insertion losses are about –0.2 dB. The filtering performance
of diplexer is taken into account in system calculations.
Signal levels
Power LevelTDMAAMPS
(For RH-14 AMPS mode PL2 = 24.7 dBm. For digital PL2 = 27.3 dBm both SB and DB, LB
and HB.)
Antenna Circuit
The antenna circuit consists of duplex filters, diplexer, and a DCT4 RF connector/switch
(X900). The maximum insertion loss is 0.3 dB.
PL227.324.4
PL323.321.1
PL419.317.8
PL515.314.5
PL611.310.5
PL77.36.5
PL83.23.2
PL9-0.9-0.9
PL10-5.3-5.3
Antenna
The RH-14 cellular antenna is an internal, dual-resonance planar, inverted F antenna
(PIFA), mounted on a common dielectric substrate.