World Leader in Advanced ILS Antennas

Model GP7 M-Array/Capture Effect, Null-Reference

WATTS ANTENNA COMPANY’S MODEL GP7

HIGHLY DIRECTIONAL BEAM-STEERED  IMAGE GLIDE PATH WIDE APERTURE ANTENNA

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

We’re Making History!

This Model GP7 provides the worlds smallest 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 GP7 Antenna element is being 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.  


Picture shows a comparison of a common ILS Image Glide Slope antenna (top) with 3 dipoles and Watts Antenna Company’s state-of-the-art Model GP7 Highly Directive, Beam Steered, ILS Glide Slope Wide Aperture Antenna having a total of 7 dipoles per array (bottom).

Features

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


THE PROOF IS IN THE CRITICAL AREA COMPUTATIONS!

Critical Area Comparisons Using M-Array Configuration

Also referred to as Capture Effect (CE) 

Figure 1.  Computed ILS Glide Slope Critical Area for an Airbus A380 Parallel to the Runway Using the Watts Model GP7 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.

Figure 2.  Computed ILS Glide Slope Critical Area for an Airbus A380 Parallel to the Runway Using the Watts Model GP7 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 GP7 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 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.

GP7 Specifications

Company:

Watts Antenna Company

Antenna Type: Directional Beam-Steered Image Glide Slope Antenna
Nomenclature: Model GP7
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: > 14  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: 3.33 Meters (131.25 Inches)
Height: 79 CM (31 Inches)
Weight:  42.18 KG Approximate (93 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.
 

 

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

GP7 Downloadable Hi-Resolution Brochure 

Watts 2019 Product Line Brochure