Evolution of High power AM transmitter technology
and
Comparison of type S7HP and TMW2100 transmitters

AM-DSB modulation in communication
 AM is the least efficient mode of
communication
 Hence, the process of generation of high
power AM-DSB signals needs to be highly
efficient

Evolution of AM Transmitter technologyEvolution of AM Transmitter technology
 < 1970:< 1970: Class-C PA and Class-B modulator using triodes.
 ~~1970: Class-D PA and Class-B modulator using tetrodes.
 ~~1984:1984: Dynamic carrier control for electrical energy saving.
 ~~1984:1984: PSM modulator using GTOs replaced Class-B modulator.
 ~~2000:2000: Modular design. MOSFET as high speed switching device
and DSP to implement the switching algorithm. (Fall out of PSM
Technology)

SOLID STATE MODULAR TRANSMITTERSSOLID STATE MODULAR TRANSMITTERS

TechnologyTechnology
 Uses solid state, high speed switching devices for generating the
RF output.
 Due to limited power dissipation of the solid state devices,
number of plug-in RF power amplifiers are used.
 Switching (sampling) rate of the PA switching is function of
instantaneousinstantaneous modulation of the carrier limited to Nyquist
criteria.
 Command for switching and control of each of the devices is
generated by high speed DSP electronics.

BenefitsBenefits
 High conversion efficiency.
 Modular design and hence redundancy in operation.
 Low cost maintenance due to inexpensive expendable components.
 Ease of operation in different modes viz AM-DSB, DCC, DRM.
 Robust protection against faults and disturbances.
 Excellent audio quality.

Connection topology of RF modules in
series
DSPem
Ec

Connection topology of RF modules/lines in parallel

Connection topology of RF modules in series || parallel

Comparison of the topology
S E R IA L P A R A L L E L M IX E D
O P E R A T IO N
M O D U L E V O L T A G E A D D E D
S A M E C U R R E N T
M O D U L E C U R R E N T A D D E D
S A M E V O L T A G E
M O D U L E V O L T A G E A N D
C U R R E N T
A D D E D A N D C O M B IN E D
S T A B IL IT Y W IT H O N E O R
M O R E M O D U L E O U T O F
O R D E R
S T A B L E
P O W E R D E C R E A S E S
U N S T A B L E
P O W E R R E M A IN S C O N S T A N T
S T A B L E U N D E R C O N D IT IO N
S M A L L U N B A L A N C E D V O L T A G E
D IF F E R E N C E
D IS A B L E D M O D U L E
M O D U L E F A U L T A L L O W E D
S H O R T - C IR C U IT
T H E N O R M A L T R A N S IS T O R
F A IL U R E M O D E
O P E N C IR C U IT
N E E D A D D IT IO N A L
P R O T E C T IO N
S H O R T C IR C U IT L IM IT E D
N U M B E R O F F A U L T Y M O D U L E
L IM IT E D
L IM IT A T IO N
H IG H V O L T A G E L IN E L E N G T H
L O A D V A R IA T IO N
H IG H C U R R E N T
L O W IM P E D A N C E
IN C R E A S E D L O S S E S
V O L T A G E A N D
C U R R E N T C O M B IN E D
T H O M C A S T S O L U T IO N
1 2 0 T O 1 6 0 M O D U L E S
IN S E R IA L
1 5 0 k W
N IL
2 L IN E S O F 1 2 8 M O D U L E S IN
S E R IA L
4 0 0 k W
P H A S E V A R IA T IO N A L L O W E D F O R B ID D E N A L L O W E D

Comparison of S7HP and TMW 2100

S U P E R V I S I O N ( S V )
F A S T S V B A S I C S V
S T A G E
P O W E R S U P P L Y
A
D
A
D
A U D I O
I N P U T
M E A S U R I N G S P C O N T R O L
A U D I O I F B A S I C S P F A S T S P R F G E N E R A T O R P R E - D I S T R
C S M C T R L
M M I R E M O T E M M I E X T . C T R L
T X C T R L
S I G N A L P R O C E S S I N G ( S P )
L I N E
P O W E R
C O O L I N G
S Y S T E M
R F S T A G E S
∑
C T R L
P O W E R S U P P L Y
M 2 W
T R A N S M I T T E R
O U T P U T
F I L T E R
D I S T R I B C O M B I N E R
P O W E R A M P L I F E R
C O O L I N G A I R
t it le :1 0 0 K W - M W M O D U L A R
* M 2 W * T X - C O N T R O L

Schematic of PA used in TMW 2100

Timing diagram of the control signals fc+
and fc-
in
PA module of TMW 2100

5 kW Power pack of TMW2100

B L O C K S C H E M A T I C O F 3 0 0 K W
T R A N S M I T T E R
T r . T r .
1 1 K V / 4 1 5 V
7 5 0 K V A
T R F - 2
1 1 K V
P O W E R
T R A N S F O R M E R
P A # 1 7
M A N A G E M E N T
A N D
C O N T R O L
E N C O D E R
A M P L I F I E R
C I R C U I T
B L O C K
M M I E X C I T E R
R E M O T E M M I
R E M O T E
D I S T R I B U T I O N C I R C U I T
L E F T L I N E
A D A P T A T I O N U N I T
P A # 1
H Y D R A U L I C
S Y S T E M
R E C T I F I E R
M A I N
R E C T I F I E R
A U X I L I A R Y
R E C T I F I E R
M A L T A N D
L O C K I N G
S Y S T E M
R F F I L T E R
R F C H A N G E O V E R
S W I T C H
D U M M Y L O A D
M A T C H I N G
U N I T
5 0 K W
M W
V E N T I L A T O R
# 2
V E N T I L A T O R
# 1
9 0 0 K V A A V R
1 2 5 K V A
D G S E T
P O W E R S U P P L Y
E N C L O S U R E
A M P L I F I E R B L O C K
P I L O T - 1 P I L O T - 2
S E L E C T I O N B O A R D
R F
C M D S
R F
S I G N A L
B L O C K
I N T E R N A L P O W E R S U P P L I E S
V L V
P O W E R
S U P P L I E S
4 1 0 V
L V I N P U T
E L C T R O T E C H N I C A L R A C K
F A U L T
C O M M A N D
H Y D R A U L I C S Y S T E M
V E N T I L A T I O N S Y S T E M V E N T I L A T O R
E X H A U S T
R F S I G N A L
L E F T T H E
R F S I G N A L
R I G H T L I N E
A M P L I F I E R M O D U L E S A S S E M B L I E S
- V in t
3 3 0 V 3 3 0 V
3 3 0 V
LVINPUTTOELECTROTECHNICALRACK
R F
T R A N S F O R M E R
1 2 0 0 A
LVGPSEXTERNAL
P A # 1 6 P A # 3 2
T R F - 1
8 0 0 A
8 0 0 A
5 0 K W L T R O O M
T x H A L L
H E A T I N G
1200A
630A
1600A
1200A
100A
SPARE
AUDIORACK
HYDRAULICS
DUMMYLOAD
VENTILATOR
F R O M O U T S I D E
F R O M
E T
R A C K

Schematic of PA used in S7HP

PA ofPA of S7 HPS7 HP

Similarities inSimilarities in S7HPS7HP andand TMW 2100TMW 2100
 The technology is similar.
 PAs use IRFP460LC MOSFETs as high speed Switching devices
in a H-bridge configuration.
 Uses DSP processors for implementing the algorithms for
module switching, thermal balancing, rotation etc.
 Uses PWM/phase modulation to get fine envelope and digital
modulation.
 Control through MMI, remote terminal etc.
 Built in DCC and DRM ready
 No hot plugging of PA modules.
 Boards are not inter-changeable.Boards are not inter-changeable.

Differences in S7HP and TMW 2100
PA topologyPA topology Series – parallelSeries – parallel SeriesSeries
Fine controlFine control 7 Dedicated PAs7 Dedicated PAs All PAsAll PAs
TechnologyTechnology
MPM-PMPM-P33
[MMultiple pparameter
mmodulator with ppulse
pprecision pphase]
MM22
WW
[MModular MMedium wwave]
Power build upPower build up 248 CSM controlled PAs
All 80 PAs are
CSM/PWM/phase controlled
Power output of each PAPower output of each PA 2.34 kW 1.25 kW
AvailabilityAvailability Blocks of 400 kWBlocks of 400 kW 10 kW to 125 kW10 kW to 125 kW

Differences in S7HP and TMW 2100
PA Module monitoringPA Module monitoring Through fuse status
Through fuse status,
correlation check
between I/P - O/P
signals, VDD and
Temperature
Signal distributionSignal distribution
Through distribution
board one each for 16
modules
Through distribution
board one for block of
each 4 modules
Supervision ofSupervision of
defective PAsdefective PAs
By multiplexing the
feedback from each PA
Defective PA is switched OFF
at power pack level and status
indicated to Control System.

Differences in S7HP and TMW 2100
WorksWorks Conflans, France Turgi, Switzerland
Defective modulesDefective modules
in circuitin circuit
Output clips shorts
Dummy module to be
inserted
Gate driveGate drive
Directly driven
through VINT PS
Through a chopper AC/DC
power supply
CoolingCooling Water and air Air

Thank you