Figure 2 ­ Comparison of measured and theoretical Radiation

patterns for the Terrestrial Link Rotman Lens.

As seen in the measured data presented in Figure 2, the REMCOM

RLD, based solely on Geometric Optics, gave measured results very

consistent with the theoretical predictions. A slight loss of power is

noted for the two beams oriented toward broadside ­ which we

attribute to side reflections from the lens attenuating the beam. The

RLD software is for obtaining a first cut model of the lens. It is

understood that the model will then be exported and optimized using

REMCOM's XFDTD software. The measured system gain of the

beamformer and the antenna array was 6 dBi which includes an

insertion loss of 10 db for the Rotman lens and the connectors.

This Rotman lens was extensively measured on a network analyzer

over a frequency range of 4.0 to 5.0 GHz.  As the targeted

Figure  3  -  Prototype  of  Rotman

lens

for

Terrestrial

frequency of operation was 4.6 GHz, we now present measured data

communications with patch array.

for input ports 1 to 8 (seen on Figure 3), showing the progressive

phase shift needed to form the beam at various scan angles at the

output ports, Figures 4 to 7. Note the good measured linearity ­

even at the most pronounced scan angle of Figure 7.

2