Rotman Lens Application Example. • Rotman Lens CST MWS Analysis. • Rotman
Lens Analysis vs. Measurements. • AMTA Paper A07-0090 Presented 11/6/07.
EHF Rotman Lens Fed Linear Array Multibeam Planar Near-Field Range Measurements CST 5th NORTH AMERICAN USERS’ FORUM 4th FEBRUARY 2008 SANTA CLARA, CA 3:40 pm - 4:05 p.m.
Mike Maybell Planet Earth Communications LLC 1983 San Luis Ave. #31 Mountain View, CA 94043-2900 650-965-7456
[email protected] John Demas Nearfield Systems Inc. 19730 Magellan Drive Torrance, CA 90502
AGENDA
2/4/2008
• Rotman Lens-True Time Delay Beamformer • Rotman Lens Application Example • Rotman Lens CST MWS Analysis • Rotman Lens Analysis vs. Measurements • AMTA Paper A07-0090 Presented 11/6/07
1A
Rotman Lens Physical Optics Design •
2/4/2008
Rotman1 lens parameters •
Four basic parameters; α, β, γ, f1 ¾ TEM transmission line lengths w computed using Rotman & Turner formulas
• •
The focal arc is a circle defined by Rotman & Turner formulas The beam pointing angles are frequency independent y L2
Parameter
y3
y2
α β
(X2,y2)
L1
w
Ψ
f2 3 focal points
α f1
x
γ Ψm f1 d Na Nb εr
Definition Focal Angle Focal Ratio Beam to Ray Angle Ratio Maximum Beam Angle Focal Length Array Element Spacing Number of Array Ports Number of Beam Ports Rel. Dielectric Constant
Formula f2/f1 sinΨ/sinα
Note: γ is the compression factor if