TWIST, GRID-TYPE POLARIZERS

Transmission polarizers are laminated microwave structures using alternating layers grids. Seavey Engineering designs and fabricates these useful devices to order.

When placed over the apertures of reflectors or flat plate arrays, they rotate or twist the plane of polarization.

Two types are available:

Type A - Fixed polarization rotation (45 or 90 degrees, for example) 

Type B - Variable polarization rotation (0 - 360 degrees) using two twisting layers. One laminate is fixed to the antenna and the second rotates. The polarization angle twists at twice the angle of the second laminate.

These are low-loss devices with a typical insertion loss of 0.2 to 0.5 dB. Certain designs have been produced for apertures up tp 8 feet across.

Individual parallel grid circuit layers (9425) can be placed over the apertures of horns and arrays to reduce cross-polarization.

pg113a
Model No. 9666-01
Type A Twist Polarizer
pg113b
Model No. 9126(13)-815 & -820
Type B Universal Twist Polarizer
pg113c
SPECIFICATIONS
Model
Number		 Frequency
GHz		 Type Polarization
Rotation, Degrees		 Size
Inches		 Thickness
Inches
9126(19A)-800 1.8 - 4.70
A
90
23.5 x 22.3
3.50
9126(08)-800 5.9 - 8.20
A
90
42.6 x 50.5
0.75
9126(19B)-800 11.0 - 11.5
A
90
51.0 x 43.1
1.00
9709-01 21.2 - 23.6
A
45
12.6 - 10.5
0.75
9666-01 23.5 - 26.5
A
45
12.6 x 10.5
0.75
9648-01 37.0 - 40.0
A
45
12.0 x 10.0
0.75
9126(13)-815 5.9 - 7.10
B
0 - 360
48.8 x 36.4
1.00
9126(13)-820 5.9 - 7.10
B
0 - 360
60.5 diameter
1.00