The cellular infrastructure build-out continues for 4G and is increasing for 5G. Realizing the potential of 5G requires more cellular antennas in the field. Protecting DC power lines is critical for high reliability of antennas. Littelfuse delivers surge protection and overcurrent protection solutions for all your data center and cloud infrastructure applications.

1. 11
Data Center & Cloud Infrastructure
Outdoor Cellular Antenna Protection (4G & 5G)

2. 2Littelfuse, Inc. © 2019 2
Cellular Infrastructure Build-out Continues For 4G And
Increasing For 5G
 Rural and suburban cellular build-out
driving 4G
 5G New Radios (NR) promise very high
data speeds and low latency for next
generation services such as
autonomous cars and smart cities
 5G NR has shorter range and is
susceptible to interference from
buildings and other obstructions
 Achieving capabilities of 5G requires
more radios 2017 2018 2019 2020 2021
LTE or 3G/4G 1,521 2,838 4,170 4,483 4,151
5G New Radios - - 159 402 685
-
500
1,000
1,500
2,000
2,500
3,000
3,500
4,000
4,500
5,000
Units(1,000s)
Worldwide Small Cell Deployment
Forecast
Realizing the potential of 5G requires more cellular antennas

3. 3Littelfuse, Inc. © 2019 3
4G & 5G use Active Antennas Which Continue To Evolve
 Reduced footprint
 More efficient delivery of power
 Small cell is key element of 5G
 COAX transitioning to more
Fiberoptic
 DC power lines susceptible to
electrical hazards
Protecting DC power lines is critical for high reliability of antenna
BBU Radios/
TXRUS/PA
Filters
Conventional
Base Station
RF COAX
RET COAX
Jumpers
BBU
Remote Radio
Head (RRH)
Fiber
Fronthaul
RET COAX
Jumpers
BBU
Active Antenna
System (AAS)
Fiber
Fronthaul
Tower
Mounted
Amplifier
RRH
(Radios/
TXRU/PA) DC Power
line
DC Power
line
DC Power
line
DC Power
line
DC Power
line
Active
Antennas
3D-MIMO
Passive
Antennas
2D-MIMO
Passive
Antennas
2D-MIMO

4. 4Littelfuse, Inc. © 2019 4
Cellular Tower with Active Antenna
Surge Protection Device ■
 MOV for surge protection
Active Antenna: ■
 Fuse for overcurrent protection
 TVS Diode for surge protection
 MOV for surge protection
 GDT for surge protection
Power Supply ■
 Fuse for overcurrent protection
 MOV for surge protection
■ Protect ■ Control ■ Sense
Baseband Unit: ■
 Fuse for overcurrent protection
 MOV for surge protection
 SIDACtor for surge protection
Remote Radio Unit: ■
 TVS Diode Array for surge protection
 MOV for surge protection
 SIDACtor for surge protection
 PTC for overcurrent protection

5. 5Littelfuse, Inc. © 2019 5
Line Power
AC
AC/DC
Power
Fiber Optic
Radio Data
Indoor
Technology Series
1
Fuse 688
MOV LV UltraMOV
GDT CG
TVS AK
Surge Protection Fuse LVSP
2 MOV C-III
3
Fuse L17T
MOV C-III
4
Fuse TLS
MOV LV UltraMOV
SIDACtor Pxxx0SD
BBU
Type 2
SPD
Battery
Power Supply
3
2
4
Outdoor
Fiber Optic Input
Active Antenna
System (AAS)
1
Cellular Tower with Active Antenna Block Diagram

6. 6Littelfuse, Inc. © 2019 6
Optical Fiber
Base Band
Processor
Unit
RF Front End
Power
Amplifier
Network
Controller
Antenna
Array
Ethernet
To BBU
Power
Supply
1
2
Technology Series
1
Fuse
456
688
MOV LV UltraMOV
GDT CG
TVS LTKAK
2
Resettable PTC PolySwitch T-Line
SIDACtor SEP
Diode Array SP3400
TVS Diode SMxx
3
TVS Diode
SMCJ
SMDJ
Resettable PTC PolySwitch T-Line
4 Polymer ESD XGD
DC Input
4
Integrated Active Antenna System (AAS) Block Diagram
RS-232 or
RS-485
3

7. 7Littelfuse, Inc. © 2019 7
We Are Your Partner For Coordinating Surge Protection
 Primary protection at furthest point up-stream = ∆
− Typically highest surge withstand capability
− May be slow to react
− Standards prescribe high test-levels
 Secondary protection at equipment = ß
− Fast-acting current diversion nearer to most sensitive electronics
− Protects until primary engages
− May not withstand primary protector tests by itself
 Coordination…
− is needed for safe operation
− assures that primary protection engages before secondary
protection fails
Active
Antennas
3D-MIMO
BBU
Active Antenna
System (AAS)
Fiber
Fronthaul
DC Power
line
ß
∆

8. 8Littelfuse, Inc. © 2019 8
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efficiently and reliably.
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9. 9Littelfuse, Inc. © 2019 9
Reliability Testing Defined By Multiple Standards
 Telcordia GR-1089
– First and Second Level Lightning Surge Tests
– AC Power Fault Tests
– Current Limiter Test
– Short Circuit Test
 ITU-T K.20
– Lighting Surge
– Power Fault
 TIA-968-A
– Voltage Surge

10. 10Littelfuse, Inc. © 2019 10
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