Table of Contents

• Summary
• Antennas
• Antenna Feeds and Microwave Components
• Radomes
• Tallguide ® Ultra Low Loss Waveguide Transmission Lines
• Custom Shelters
• The Company and Shareholders

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Summary

AFC has been in the business of applying composite fiberglass, sandwich composite and other materials as a means of solving electromagnetic structural problems for 30 years. These unique problems have led to products which range from conical horn antennas up to 14 foot diameter (composed of feed, horn launcher and composite foam core reflector all enclosed in a radome), parabolic and offset dish antennas to 7 meters diameter, radomes---solid laminate, sandwich composite foam core and dielectric space frame to 140 foot diameter, specialized TEMPEST, flyaway modular shelters, microwave components and feed systems including the space qualified OMT recently placed aboard the TDRSS satellite and launched from the Atlantis Space shuttle, to Tallguide ®, an ultra low loss waveguide transmission line from 5 Ghz to 120 Ghz. Several million square feet of conical horn radomes alone have been delivered to the exacting demands of AT&T, the Bell operating companies, MCI, Sprint etc.. C-130 Fly-Away shelters to 30 feet---equipped with TEMPEST design, double RF doors, CIPHER locks and security systems have been a part of several classified programs. And two days before the air war started in the Gulf, AFC trained a US Army team and air shipped via C-141 a 68 foot dielectric space frame radome to Saudi Arabia. AFC supplies GOES 3.7, 5 and 7 meter diameter antennas with fixed, motorized and hand-crank pedestals to NASA, the US Military and prime contractors.

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Antennas

CH-10 Conical Horn	Antenna with Dual Beam Feed

And in high terrestrial interference areas, where satellite dish antennas fail to work, AFC offers the CH-14, the world largest commercial conical horn. The CH-14 horn exhibits very sharp spatial selectivity, grabbing signals from a specific pointing direction and rejecting others. Today, AFC offers a line of totally unique terrestrial and satellite communications antennas designed for the highest levels of performance, extreme durability and low delivery and maintenance costs.

CH-14 World Largest Conical Horn

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Antenna Feeds and Microwave Components

TDRSS Satellite Ku-band Orthomode Coupler In support of the antenna industry, AFC offers a broad range of microwave components, combining networks, antenna feeds, multi-satellite feeds, orthomode polarizers, launchers and ultra low loss waveguide. Manufacturing techniques employed are aimed at achieving desired technical results and cost objectives for commercial and military/agency applications. Frequency bands covered are up to 100 Ghz. The Satellite Communications Antenna Feeds data sheet contains information on commonly purchased feed types. Multi-Sat Feed for Two-Degree Spaced Satellites describes a class of multi-beam feed systems specifically designed for 4.5 to 9 meter diameter antennas. For smaller antennas, see Dual Beam Retrofit Multi-Satellite Feed for 3.7 m (12 ft.) Diameter Class Antennas. Design and technical information, installation and test results may be found in Multi-satellite feed system for 2-degree satellite spacing reprinted from the April 1992 CED magazine.

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Radomes

12.5 m (41 ft.) Diameter Impedance Matched Radome for S-Band Radar.

Radome transmission loss is composed of the insertion loss from the RF signal passing through the radome wall and from the scattering loss off the panel flange framework. In most cases, the scattering loss from the framework is several times greater than the wall insertion loss. To reduce scattering loss, AFC engineers use a technique known as impedance matching to "tune out" framework loss. As required by sophisticated electrical performance requirements, inductive elements (wire, metallic strips etc.) may be laminated into the dielectric flanges to impedance match scattering loss. Any of the four DSF radome types may be impedance matched. Please refer to the Radome Network Home Page for more information on impedance matched radomes.

Every DSF radome exhibits the RF property that the total transmission loss, scattering plus wall insertion loss, approaches zero dB at low frequencies (as opposed to "Metal Space Frame Radomes" whose loss increases without limit. This property is important for UHF/VHF emergency radio communications contained within the radome). The superior performance and Advantages of Dielectric Radome Technology are evident in the worldwide Defense Satellite Communications System (DSCS), weather satellite and radar, air surveillance radar and Intelsat Communications applications.

The four DSF radome types are:

Thin Membrane	Solid Laminate	2-Layer Sandwich	3-Layer Sandwich
The thin membrane wall DSF radome where adjacent panel flanges carry all the environmental loads. Wall thickness is usually 0.040 inch or less.	The solid laminate wall DSF radome. Wall thickness is typically 0.090 inch.	Adding a layer of foam to the inside thin membrane wall DSF radome forms a 2-layer sandwich wall radome. Foam thickness is chosen primarily for thermal insulation and cost objectives.	The composite 3-layer sandwich foam core wall radome. Core thickness is chosen as 1/4 wavelength for the highest RF signal frequency. For a given radome diameter, the 3-layer sandwich foam core radome is the most expensive version.

For more sandwich wall details, AFC's Application Note for Radome Thermal Insulation discusses two and three multi-layer sandwich wall radomes and their significant insulation value differences.

AFC engineers have developed a family of dielectric space frame radomes based on a range of required radome diameters. A set of radomes within a given range of radii will have identical panel count, panel shape and overall geometric layout. Individual panel size and the flange angles, which are radius dependent, will differ to accommodate the radome's overall shape factors. Spherical truncation is also radome specific, and is accommodated by sub panels unique to each requirement. This process of engineering complex designs from the macro point of view has greatly simplified the structural design phase. Emphasis is placed on meeting the material strength requirements of the environmental specifications and of the important electromagnetic constraints as opposed to continually reinventing the radome.

Radome accessories customize a radome to suit particular requirements. Accessories may include lightning protection, obstruction lights, ventilation, base collar, personnel door, indoor lights and power kits, hydrophobic coating and impedance matching. For more information, visit AFC's Dielectric Space Frame Radome data sheets, Radome Capability. and other data sheets summarized below.

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Tallguide ®

Tallguide TG31 for 33 to 55 Ghz. TG31 replaces WR22 waveguide.

Ultra low loss Tallguide (

Typical applications are satellite uplinks and radar. For example, the ASDE 3 short pulse airport surveillance radar, uses Tallguide at most major airports within the US, Canada and Europe. Often, ASDE 3 Tallguide runs are several hundred feet long. For satellite communications applications, Tallguide increases uplink power --- significantly reducing earth station cost. For further satellite communications data, see How to Combat Uplink Power Loss reprinted from the January 1995 issue of Satellite Communications.

Specific Tallguide component design information for Tallguide frequency bands may be found at the Tallguide Home Page, which is the starting point for all Tallguide information.

For other Tallguide frequency bands and component information, visit the Tallguide data sheets below.

5.8 - 7.0 Ghz

7 - 10 Ghz

8.2 - 12.4 Ghz

10 - 15 Ghz

12 - 20 Ghz

15 - 22 Ghz

17 - 27 Ghz

22 - 33 Ghz

26 - 40 Ghz

33 - 55 Ghz

50 - 75 Ghz

60 - 90 Ghz

75 - 110 Ghz

WR137

WR112

WR90

WR75

WR62

WR51

WR42

WR34

WR28

WR22

WR15

WR12

WR10

TG215

TG170

TG134

TG115

TG87

TG80

TG62

TG50

TG40

TG31

TG23

TG17

TG16

Tallguide Home Page

Tallguide Data Sheet

How to Combat Uplink Power Loss

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Custom Shelters AFC manufactures custom shelters to solve a variety of needs. Typical examples are transportable uplinks and secure airborne deliverable shelter modules. In todays tactical, highly mobile atmosphere, shelters often encompass dual use roles. Such tactical applications include an airborne deployed environmentally controlled 8x8x20 foot shelter housing a complete 26 foot diameter radome. Accessories and optional features may include TEMPEST design, personnel and equipment doors, alarm and emergency systems.

Custom Shelter and Antenna System

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The Company and Shareholders

AFC's headquarters are in Ocala, Florida, which is located 1-1/2 hours north of Orlando. From Orlando international airport, take the Florida Turn Pike north to Highway 75. Florida Map Orlando to Ocala, gif 38K

A complete Internet WWW AFC document index may be found in Antennas for Communications (AFC) Home Page Document Summary List.

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