Rojone Products - Lightning Protection Devices

Lightning Protection Devices

Lightning can generate high power surges to electronic equipment, and extensively damage communications
networks. Therefore lightning protectors are needed to protect sensitive equipment from these harmful impulse.
Protection devices should be physically located close to the equipment, the closer the better.
Common locations in wireless infrastructures are at the top of the mast where the transmission line
exists the antenna and at the entrance or inside the cabinet where the transmission line enters the base
station electronics. Applications that use tower mounted equipment require additional lightning protection.

Quarter Wave Stub (194kb)
(QWS) Protection (124kb)

This technology is based on a 3 port coaxial device.
The metallic port creates a short-circuit between the inner and the outer conductors, the stub's length is one quarter of the centre frequencies wavelength. Quarter wave protectors work like band pass filters.
They operate within a specific frequency band.

In normal use, the RF signal flows through the quarter wave lightning protector.
When lightning hits the antenna, the current will flow through the cable to the installed lightning protector, as lightning strikes operate at low frequencies (outside the protectors working frequency band), it will be instantaneously diverted through the short-circuit to ground therefore protecting critical equipment, such as Base Transceiver.

The Quarter Wave Stub Lightning protector is able to survive repeated surges as it is a mechanical device. Surges/impules will always be shunted to ground. Only a low residual voltage, less than 15V, can pass through to the equipment.

Single band devices for common wireless applications such as CDMA, GSM, PCS, DCS.

Advantages :
Quarter wave protectors do not require any maintaining.
They achieve high Passive intermodulation performance & they only pass the lowest residual voltage.

Disadvantages :
Quarter Wave Stub protectors can not pass DC Signals
Size is larger then Gas Discharge Lightning protection devices.

GAS DischargeTube (124kb)
(GDT) Protection (124kb)

Gas Discharge Tube Protectors look like in-line coaxial adaptors. These devices contain a field replaceable gas capsule placed between the inner and outer conductors. Unlike quarter wave protectors, gas tube surge arresters are broad band devices DC-2.5 GHz.

Gas discharge protectors work as a voltage filter. During normal operation, the gas inside the tube is and remains inert. Signal can pass through the surge arrester to the equipment. When lightning strikes the antenna, current will flow through the cable to the surge protector. the voltage, appearing across the capsule, increases. When it reaches the DC spark over voltage, the gas ionizes and becomes conductive. Current is then diverted through the gas capsule to ground. A residual voltage will nevertheless reach the equipment.

Once the pulse has been discharged to ground, the gas capsule comes back to its initial state.
Life of the gas capsule depends on the number of strikes and their intensity. The same capsule can divert to ground either a few impulse of 20KA or only one of 40KA. Regular control and maintenance is recommended.

Gas discharge protectors are delivered without gas capsules. A choice of gas capsules are available offering different static spark over voltages. Selection should be made according to maximum transmission power.

Advantages :
Gas discharge capsule protectors are the only solution when DC injection is required.
(example : when a tower mounted amplifier is mounted)
These devices are typically smaller in size and offer wide band performance.

Disadvantages :
Regular control & Maintenance is required.

SINGLE BAND QUARTER WAVE STUB LIGHTNING PROTECTORS

part number frequency range (MHz) V.S.W.R. Insertion loss L (mm) weight (g)

R445 110 020 1710 - 1880 < 1.20 < 0.2 dB 42 562

R445 111 020 1850 - 1990 < 1.20 < 0.2 dB 40 562

R445 112 020 880 - 960 < 1.15 < 0.1 dB 72 562

R445 113 020 866 - 894 < 1.15 < 0.1 dB 72 562

MULTI BAND QUARTER WAVE STUB LIGHTNING PROTECTORS

part number frequency range (MHz) V.S.W.R. Insertion loss weight (g)

R445 119 020 824 - 960
1700 - 2000 < 1.20 < 0.1 dB 400

CABLE MOUNTING QWS LIGHTNING PROTECTORS FOR CABLES

part number frequency range (MHz) V.S.W.R.* Insertion loss* L (mm) weight (g)

R445 110 xxx 1710 - 1880 < 1.20 < 0.3 dB 42 275

R445 111 xxx 1850 - 1990 < 1.20 < 0.3 dB 40 275

R445 112 xxx 880 - 960 < 1.20 < 0.2 dB 72 275

R445 113 xxx 866 - 894 < 1.20 < 0.2 dB 72 275

xxx = 030 for 141" cable - 040 for SHF 5 LI cable.
* measured with 300 mm cable and one right angle 7/16 connector.

Telecom's Index

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part number	frequency range (MHz)	V.S.W.R.	Insertion loss	L (mm)	weight (g)
R445 110 020	1710 - 1880	< 1.20	< 0.2 dB	42	562
R445 111 020	1850 - 1990	< 1.20	< 0.2 dB	40	562
R445 112 020	880 - 960	< 1.15	< 0.1 dB	72	562
R445 113 020	866 - 894	< 1.15	< 0.1 dB	72	562

part number	frequency range (MHz)	V.S.W.R.*	Insertion loss*	L (mm)	weight (g)
R445 110 xxx	1710 - 1880	< 1.20	< 0.3 dB	42	275
R445 111 xxx	1850 - 1990	< 1.20	< 0.3 dB	40	275
R445 112 xxx	880 - 960	< 1.20	< 0.2 dB	72	275
R445 113 xxx	866 - 894	< 1.20	< 0.2 dB	72	275