World Leader in Advanced ILS Antennas

Model GP5-A1 M-Array/Capture Effect, Null-Reference

WATTS ANTENNA COMPANY’S MODEL GP5-A1

HIGHLY DIRECTIONAL BEAM-STEERED  IMAGE GLIDE PATH WIDE APERTURE ANTENNA

CATEGORY I/II/III INSTRUMENT LANDING SYSTEM
FEATURING MINIMAL CRITICAL & SENSITIVE AREAS

We’re Making History!

Watts Antenna Company’s model GP5-A1 provides smaller critical areas for Category I/II/III Instrument Landing Systems.  Watts has recognized that worldwide engineering practices employed to overcome difficult site problems with image glide path (GP) antenna systems indicate that the antenna lateral radiation pattern is being substantially challenged in the modern airport environment.  Introduction of larger aircraft such as the Airbus A380 and airport efficiency constraints are also driving a reduction in the size of the critical area of the Glide Path system in order to take advantage of the larger jets and to increase airport capacity.

The Model GP5-A1 Antenna element, nomenclature GP5-A1, has been designed and manufactured by Watts Antenna Company to provide highly accurate guidance information to an approaching aircraft while permitting increased flow of aircraft traffic in the vicinity of the GP tower.  The initial development was undertaken by the manufacturer starting in the fourth quarter of 2003.

Features

  • Directive, narrow beam produces optimum pattern in airport multipath environments.
  • Asymmetric radiation pattern provides greater use of all taxiways in the vicinity of the GP mast.
  • Rejects sources of both static and dynamic multipath on the side of the runway containing the tower. 
  • No shim adjustment necessary.


THE PROOF IS IN THE CRITICAL AREA COMPUTATIONS!


M-ARRAY (Capture Effect) Configuration For Critical Area Comparisons Of Watts MODEL GP5-A1, Kathrein & FA8976 Antenna Arrays

GP5-A1 M-Array/CE w/Additional -6 Degree Rotation 

Figure 1.  Computed ILS Glide Slope Critical Area for an Airbus A380 Parallel to the Runway Using the Watts Model GP5-A1 Beam Steered Directional Antenna in M-Array Configuration, also referred to as Capture Effect (CE). This Figure Shows the Addition Critical Area Reduction Achieved by Mechanically Rotating the Already Canted Beam by an Additional 6.0 Degrees Toward the Runway. (The Dashed Line on the Plot Represents a Taxiway Offset Distance Where the Tower to Wingtip Separation is Only 5 Meters (16.4 Feet).  The Black Triangular Shape Represents the Location of the Glide Slope Tower.)

GP5-A1 M-Array/CE w/Additional -3 Degrees Rotation

GP5-A1 M-Array w/o Additional  Rotation

Figure 3. Computed ILS Glide Slope Critical Area for an Airbus A380 Parallel to the Runway Using the Watts Model GP5-A1 Beam Steered Directional Antenna in M-Array Configuration, also referred to as Capture Effect (CE). The Dashed Line on the Plot Represents a Taxiway Offset Distance Where the Tower to Wingtip Separation is Only 5 Meters (16.4 Feet). The Black Triangular Shape Represents the Location of the Glide Slope Tower.

Figure 2.  Computed ILS Glide Slope Critical Area for an Airbus A380 Parallel to the Runway Using the Watts Model GP5-A1 Beam Steered Directional Antenna in M-Array Configuration, also referred to as Capture Effect (CE). This Figure Shows the Addition Critical Area Reduction Achieved by Mechanically Rotating the Already Canted Beam by an Additional 3.0 Degrees Toward the Runway.  The Dashed Line on the Plot Represents a Taxiway Offset Distance Where the Tower to Wingtip Separation is Only 5 Meters (16.4 Feet).  The Black Triangular Shape Represents the Location of the Glide Slope Tower.

Figure 3.  Computed ILS Glide Slope Critical Area for an Airbus A380 Parallel to the Runway Using the Watts Model GP5-A1 Beam Steered Directional Antenna in M-Array Configuration, also referred to as Capture Effect (CE).  The Dashed Line on the Plot Represents a Taxiway Offset Distance Where the Tower to Wingtip Separation is Only 5 Meters (16.4 Feet).  The Black Triangular Shape Represents the Location of the Glide Slope Tower.

Kathrein M-Array/CE

FA8976 M-Array/CE

Figure 4.  Computed ILS Glide Slope Critical Area for an Airbus A380 Parallel to the Runway Using the Kathrein Antenna in M-Array Configuration, also referred to as Capture Effect (CE).  The Dashed Line on the Plot Represents a Taxiway Offset Distance Where the Tower to Wingtip Separation is Only 5 Meters (16.4 Feet).  The Black Triangular Shape Represents the Location of the Glide Slope Tower.

Figure 5.  Computed ILS Glide Slope Critical Area for an Airbus A380 Parallel to the Runway Using the FA8976 Antenna in M-Array Configuration, also referred to as Capture Effect (CE).  The Dashed Line on the Plot Represents a Taxiway Offset Distance Where the Tower to Wingtip Separation is Only 5 Meters (16.4 Feet).  The Black Triangular Shape Represents the Location of the Glide Slope Tower.



Model GP5-A1 Specifications

Company:

Watts Antenna Company

Antenna Type: Directional Beam-Steered Image Glide Slope Antenna
Nomenclature: Model GP5-A1
Color: International Orange and White
Coating: Icephobic
Frequency Range: 329.0 to 335 MHz
Polarization: Horizontal
Radome Type: Full Cover-Fiberglass
Reflector Type: 90 Degree Trough and Corner
Maximum Power: 50w CW
Input: Type N Female Connector
Pattern Type: Asymmetric
Gain: > 13  dBd
Beam Displacement: > 6 Degrees Nominal * See Note
-3 dB Beamwidth: 23 Degrees Nominal
Sidelobe Suppression: 25 dB Nominal
Front-to-Back Ratio: >21 dB Nominal
Input Impedance: 50 Ohms Nominal
VSWR: < 1.25 to 1
Distribution Loss: < 1 dB
Distribution Isolation: > 22 dB Between Ports
Monitor Impedance: 50 Ohms Nominal
Monitor Output: Type N Female Connector
Monitor Coupling: > 20 dB Nominal
Temp Range: -55 to +75 Degrees C
Lateral Thrust: 1450 N at 160 km/h
Max. Wind Velocity: 200 km/h (incl. 1/2″ radial ice)
Length: 2.69 Meters (106 Inches)
Height: 79 CM (31 Inches)
Weight: 34.02 KG Approximate (75 lbs)
Heaters: Not Needed
NOTE:  Up To An Additional 6 Degree Physical Beam Displacement In Either Direction With Shim Kit
   
Material: Dipole System: Aluminum.

Reflector: Aluminum w/ Icephobic  Coating (orange).

Radome: Fiberglass (white).

All Screws and Nuts: Stainless Steel.

   
Scope of Supply: Antennas w/ Mounting Hardware, Shim Kit and Instruction Manual.
Mounting Hardware: B-Line 304 Stainless Steel Mounting Struts and Components.
 Lightning Protection: Antenna is DC Grounded Including Inner Conductors.

 

CATEGORY I/II/III INSTRUMENT LANDING SYSTEM
FEATURES MINIMAL CRITICAL AND SENSITIVE AREAS

 


THE GP5-A1 IS THE ANSWER TO SMALLER CRITICAL &
SENSITIVE AREAS AND GREATER AIRPORT CAPACITY

Critical Area Tests Conducted in Zurich Switzerland with
a 747 Aircraft Watts GP5 Series Image Glide Slope Antenna
Element in an M-Array
WATTS ANTENNA COMPANY
70 North Plains Road – Suite H
The Plains, Ohio 45780-1156
USA – Manufacturing Facility
Phone: +1.740.797.9380; Fax: +1.740.797.9787

EMAIL: INFO@WATTSANTENNA.COM

GP5-A1 Downloadable Hi-Resolution Brochure

Watts 2019 Product Line Brochure