SPINNER offers a premium choice of coaxial surge protectors. It covers all relevant RF applications for which a surge protection is necessary.
Surge protectors can be used in installations for analog and digital communication such as TETRA, GSM900/1800, UMTS, WiMAX and LTE. They are also suitable for communication lines in tunnels with overhead contact wires, as well as for applications in connection with radiating cables. Another type are Bias-Ts for DC and frequencies up to 10 MHz (according to Antenna Interface Standards Group).
Surges are mainly caused by electromagnetic fields generated by nearby lightning strokes. The frequency of lightning varies regionally very much. But in total there are 6,000 lightning strikes per minute worldwide!
A reliable protection against surges is given only by a proper installation and regular maintenance depending on the protector type.
TYPE I: Surge protectors with gas discharge arrestor
Function: At the sparkover voltage an arc occurs between the electrodes of the discharge arrestor and thus the voltage between the electrodes is reduced to the arc discharge voltage (approx. 15 V). The static sparkover voltage is defined at a rise time of 100 V/s and is characteristic for the type of the Arrestor.
Application: Universal broadband (DC to 2500 MHz).
Advantages: DC transmission possible
Disadvantages: Maintenance necessary (every 3 to 4 years); RF power limited; high Intermodulation.
TYPE II: Surge protectors with quarter wave stub
Function: The short at the end of the stub is transformed to an open at the bottom thus the main line is (nearly) not influenced. The nature of the stub line is responsible for the bandwidth of the device. The stub can be perpendicular to or folded into the axis of the main line (in-line design).
Application: Mobile bands (single to triple band).
Advantages: No maintenance; High RF power rating; Very low intermodulation.
Disadvantages: No DC transmission possible; Restricted bandwidth.
TYPE III: Surge protectors with quarter wave stub and inner DC break
Function: The stub behaves like in Type II and the DC break prevents any DC current getting into the transceiver. Additionally it works as a further transforming element and thus the stub can be improved in bandwidth.
Application: Multiple mobile band (800 to 2700 MHz).
Advantages: Like Type II: No maintenance; High RF power rating; Very low intermodulation
Plus:
Nearly zero residual pulse voltage and energy; Extended bandwidth
Disadvantages: No DC transmission possible; Operational direction defined (only 1 protected port)
TYPE IV: Surge protectors with quarter wave stub and decoupled gas discharge arrestor (hybrid)
Function: The short at the end of the stub is replaced by a capacitance (short for RF) and a gas discharge arrestor (short for the surge). The main line is decoupled from the effects of the Arrestor by the stub. The inner and outer conductor of the main line are not galvanicaly connected thus DC (and very low frequencies) can be transmitted.
Application: Mobile band with remote antenna amplifier on the mast (broadband).
Advantages: DC transmission possible; Transmission of AISG signals; High RF power rating; Very low intermodulation
Disadvantages: Maintenance of the GDT necessary.
TYPE V - Bias-T with surge protector
Function: A low pass filter (RF block) is added parallel to 2 shorting devices of a hybrid. The other port of the filter is led to the DC connection.
Application:
Feed of DC supply for amplifiers on the mast to a coaxial feeder cable (broadband).Advantages: Decoupled arrestor with quarter wave stub; Inner conductor to transceiver DC blocked; High RF-DC isolation; Low intermodulation
Disadvantages: Nothing known.
TYPE VI – Bias-T with hybrid, fine protector,Bias-T and Modem
Function: The Low Pass Filter (RF block) is amended with a fine protector (Varistor) and a modem board. The connector for digital data and DC is a circular multipole type which is compatible with the AISG specification.
Application: Feed of DC supply for amplifier and control signal for „Remote Tilt Antenna“ to a coaxial feeder cable.
Advantages: Like Type V plus Modem for AISG signals (carrier 2,176 MHz); Fine protector to protect the modem
Disadvantages: Nothing known.
