OVERVIEW

COM-TECH designs and manufactures a comprehensive range of output bandpass Filters for Broadcast TV and Radio Transmitters.
COM-TECH Filters are available with different cavity sizes, for low to high power applications, and with different number of poles, to match all masks and standards requirements (DVB, ATSC, ISDB, DAB).

COM-TECH Filters are easily and Fully Tunable all over their operating band, are Temperature Stabilized, and have a built in DC Short. They are equipped with a Monitor Probe and feature a convenient Interchangeable Connector System.
COM-TECH Filters make use of innovative and proprietary design techniques, such as: XLine, DualCross, SIR, Interdigital Hairpin, EVA-Mode.
Low power Filters can conveniently be integrated into 19” Rack Shelves. Medium and high power Filters can be provided with Heat Sinks, Forced Air Cooling and Liquid Cooling to efficiently increase their input power.

The FILTERS family is coded and categorized firstly with reference to the operating frequency band (UHF Filters, VHF B.III Filters…), subsequently by Filter type (Bandpass or Balanced), and finally by Filter Series (CL Series, FC Series…)

LINKS

UHF Filters

VHF B.III Filters

VHF B.I-II Filters

DAB Filters

FM Filters
Frequency Range 470-862 MHz 174-240 MHz 47-100 MHz 174-240 MHz 87.5-108 MHz
Standards DVB-T / T2
ATSC
ISDB-T		 DVB-T / T2
ATSC
ISDB-T		 DVB-T / T2
ATSC		 DAB / DAB+ / T-DMB
Order 5, 6, 7, 8-Pole
3, 4-Pole (Analog)		 6, 8-Pole
3, 4-Pole (Analog)		 6-Pole 6, 7, 8-Pole 2, 3-Pole
Techniques XLine
DualCross		 XLine
DualCross
SIR		 Interdigital Hairpin Design
EVA-Mode		 DualCross
SIR		 EVA-Mode
Cavity Size 20 mm to 220 mm 30 mm to 200 mm 60 mm to 300 mm 60 mm to 200 mm 80 mm to 220 mm
RMS Input Power 80 W to 36 kW 150 W to 50 kW 325 W to 25 kW 250 W to 14 kW 500 W to 2.5 kW

FEATURES

Full Band Tunability
COM-TECH Filters and Combiners are designed to be easily and completely tunable:

  • Fully tunable all over their operating band
  • Tunable in accordance to all worldwide standards, channel widths and regulation masks
  • Customizable Tunings in accordance with Customer specifications
  • Designed to be easily tuned (Tuning Instructions available on request)
  • Engineered to be tuned with a standardized set of tools (Tuning Toolbox available on request)

Temperature Stabilization
COM-TECH Filters and Combiners feature a state-of-the-art Temperature Stabilization, achieved through:

  • Innovative interactive CAE design (3D EM and Fluid Dynamic simulation)
  • Accurate choice of materials
  • Environmental and laboratory tests

DC Short
COM-TECH Filters and Combiners have a built-in lightning protection:

  • Solid DC Short Circuit towards ground on the input/output couplings
  • No Open Circuits, in order to avoid dangerous charge accumulations
  • Full protection towards the antenna side

Output Monitor Probe
COM-TECH Filters feature a capacitive, non-directive Output Monitor Probe, providing a reference signal on the output port:

  • SMA or SMB female connector available
  • Available on both sides (according to the position of the output port)

Interchangeable Connector System
COM-TECH products feature an interchangeable and modular connector system, based on unified mounting panels.
Each panel accept different connectors, allowing a wide choice of connections to be mounted on the same product:

  • Panel sizes: 25 mm, 32 mm, 64 mm, 100 mm, 130 mm, and 150 mm
  • Wide choice of connectors available on each product
  • Easy connector change

XLine: Extracted-Pole Elliptical Response
COM-TECH innovative and proprietary Extracted-Pole design technique, available on 6 and 7-pole low-power Filters (CL Series) and Combiners (SB, DB Series):

  • Two Transmission Zeros
  • Compact, in-line form factor
  • Balanced Combiners: Adjacent Channel Combination

DualCross: Double Cross Coupling
COM-TECH innovative and proprietary Double Cross-Coupling design technique, available on 6 and 8-pole medium and high power Filters (FC, TF, TS, TC, BF Series) and Combiners (SM, SF, DM, DF Series):

  • Four Transmission Zeros
  • Enhanced Selectivity
  • Optimum Insertion Loss and Efficiency
  • Balanced Combiners: Adjacent Channel Combination

SIR; Interdigital Hairpin; EVA-Mode
COM-TECH innovative and proprietary designs, leading to very compact yet full-band VHF and FM Filters:

  • SIR: Novel resonator design, for compact VHF B.III Filters (TS Series)
  • Interdigital Hairpin: Unique resonator design, for ultra-compact low-power VHF B.I-II Filters (HR Series)
  • EVA-Mode: Highest Quality Factor in the smallest space, available on VHF B.I-II and FM Filters and Combiners (HE, CE, ME Series)

Coding
Filters product codes are named with reference to Series, Order, Technique, Size, and Band:

Series CL, FC…: Combline, Folded Combline…
Order 4, 6, 8….: No. of Poles
Technique E: Cross Coupling     X: XLine     D: DualCross     P: All-Pole     N: 2-Notch
Size 60, 80…: Cavity Size in mm
Band C: UHF    B: VHF B.III     A: VHF B.I-II     R: DAB     F: FM

OPTIONS

19″ Rack Shelves
COM-TECH products have been engineered to be easily and conveniently fit into 19’’ Rack Shelves. COM-TECH can provide standard and customized solutions to integrate Filters, Combiners, Directional Couplers, Lowpass Filters, and other components and accessories into 19’’ Rack Shelves:

  • Specifically designed for COM-TECH Filters and Combiners
  • Compatible with standard 19’’ Racks
  • Customizable front panel

Notes

  • Components inserted in 19’’ Rack Shelves, with limited or no ventilation, might suffer from an increased over-temperature; power ratings should be consequently reduced
  • In any applicable case, the body temperature must be kept below the maximum value (65°C, 149°F)

Heat Sinks
Heat Sinks expressly designed to efficiently reduce the over-temperature on Filters and Combiners, and to consequently increase their maximum operating power:

  • Specifically designed for COM-TECH Filters and Combiners
  • Add-on option, can be conveniently added subsequently

Notes

  • Power ratings with the Heat Sinks Option are calculated with fins in vertical position and with no obstructions to the natural air flow
  • Power ratings can be further increased with the aid of extra ventilation (E.g. through the internal transmitter ventilation)
  • In any applicable case, the body temperature must be kept below the maximum value (65°C, 149°F)

Forced Air Cooling
The innovative Forced Air Cooling system allows to dramatically reduce the over-temperature on Filters and Combiners, and to consequently increase their maximum operating power. Thanks to the downsizing possibility, the Forced Air Cooling allows significant cost and space savings:

  • Complete and standalone system, not requiring any external parts
  • Variable speed fans controlled by microprocessor, allowing fans to operate at the minimum flow
  • Premium quality DC 24 V brushless fans, engineered to be quickly and easily replaced
  • Multi-standard (110-230V, 50-60 Hz) switching power supply
  • Contact Alarm for over-temperature, missing power or any kind of electrical failure
  • Add-on option, can be conveniently added subsequently 

Notes

  • In any applicable case, the body temperature must be kept below the maximum value (65°C, 149°F)

Liquid Cooling
The innovative Liquid Cooling system allows to dramatically reduce the over-temperature on Filters and Combiners, and to consequently increase their maximum operating power. Thanks to the downsizing possibility, the Liquid Cooling allows significant cost and space savings:

  • Conveniently integrates with the transmitter liquid cooling system
  • Compatible with most NTP connecting threads
  • Chemically compatible with available coolant liquids
  • Thermo-sensor included (70°C – 158°F N.C. SPST)
  • Add-on option, can be conveniently added subsequently

Notes

  • In any applicable case, the body temperature must be kept below the maximum value (65°C, 149°F)