Tallguide ® Layout Design Rules of the Run

The purpose of this article is to present design rule tips on Tallguide layout design. Like rigid waveguide, Tallguide runs need to be laid-out between the transmitter starting point and the antenna. Often the Tallguide end location is an antenna feed assembly or azimuth or elevation rotary joint. Since the transmitter control room angular orientation and elevation may differ from the antenna and may have several hundred feet separation, computer aided drafting programs are one method of keeping track of the layout features. Of course, back-of-the envelope sketch drawings serve the same function.

DBS DirecTV broadcast site, California, using 9m and 11m antennas. Tallguide TG87 is used on each antenna uplink.

Tallguide Design Rules

Line Item	Component or Feature	Design Tip
1.	Transition	Every Tallguide run begins with and ends with a Tallguide transition from standard WR waveguide into or out of Tallguide. Transitions come in two models: -1 or –2. When –1 is added to the Tallguide transition model number, the designation refers to a WR waveguide input flange that is a flat cover flange. In contrast, the –2 designation refers to a WR waveguide pressure gasket grooved flange. For example, part number 181-1078-1 refers to a TG115 transition with a mating WR75 flat cover flange.
2.	Mode Suppressor	Every Tallguide run contains one mode suppressor located between the input and output transitions. Mode suppressors are reciprocal devices. Either end may be used as input or output.
3.	High Power Runs Mode Suppressor Location	For high power Tallguide runs, the mode suppressor is located on the output (antenna) side of the run just before the output transition. Low power is defined as 1/10 the maximum Tallguide power rating. High power is everything else.
4.	H-Plane Bend	A Tallguide H-plane bend is a bend in the broad wall. There is no change in polarization direction. AFC fabricates special H-plane bend angles for customers all the time. Contact AFC's sales department to inquire about your unique bend angle.
5.	Twist	A twist changes polarization direction. For example a 90-degree twist changes vertical polarization into horizontal polarization.
6.	E-Plane Bend	There are no direct methods of fabricating a Tallguide E-plane bend (a bend in the narrow wall) and keeping transmission loss low. To create a Tallguide E-plane bend substitute, a Tallguide E-plane bend is composed of an H-plane bend and a twist. For example, a 90-degree E-plane bend uses a 90-degree H-plane bend and a 90-degree twist.
7.	Straight Section	Tallguide straight sections may be fabricated in any length up to 144-inch (3.7-m). When ordering straight sections, the length in inch units are added to the model number as 3 digits. For example, part number 181-0911-076 refers to a TG115 straight section of length 76-inch (1.93-m).
8.	Tallguide Straight Section TBD Lengths and Layout Uncertainty	Due to inadequate site knowledge, to customer modifications and to system engineering design changes, Tallguide layouts are often not known with any great precision. To accommodate design uncertainty and still meet scheduled deployment, some straight sections may be ordered with a "to be determined" (TBD) length. AFC will prepare the TBD straight section for immediate fabrication for any length up to 144-inch (3.7-m). A TBD straight section is ordered by attaching the letters TBD to the part number. For example, part number 181-0911-TBD refers to a TG115 straight section of length "to be determined."
9.	Tallguide Flange and Pressurization	Tallguide flanges are high precision gasket grooved flanges. Tallguide components are shipped with Tallguide pressure gaskets and hardware.
10.	Layout Notes	Keep track of Tallguide component lengths for the transition, mode suppressor, H-plane bend and twists. Because of these components physical length, straight section lengths must be modified to accommodate such components.
11.	Tallguide Cross-section	Like waveguide, the flange height and width determine the Tallguide cross-section. Cross-section is important when placing Tallguide into a plastic pipe or carrier.
12.	Tallguide Hangers	AFC supplies both rigid and sliding hanger for many Tallguide bands. Hangers are usually spaced every 5-ft (1524-mm).
13.	Tallguide Installation	Tallguide installs like ordinary waveguide. No special tools or alignments are necessary.
14.	Waveguide and Tallguide	The electric field of waveguide is straight and parallel to the narrow waveguide wall. In contrast, the electric field of Tallguide is parallel to the broad Tallguide wall. The name, Tallguide, is derived from the "tall" appearance of the Tallguide rectangular shape in comparison to waveguide. Note that the Tallguide cross-section is larger than waveguide.

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

5.8 - 8.2 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 Data Sheet

How to Combat Uplink Power Loss

AFC manufactures, markets and sells worldwide satellite dish antennas, radomes, antenna feeds, microwave and waveguide components and ultra low loss waveguide transmission line Tallguide. Our customers serve the broadcast, communications, radar, weather and cable industry, defense, government, and government agencies worldwide. AFC's quality control manufacturing standards are certified under ISO 9001 : 2015.

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