NSA

Range limited antenna includes at least two sets of antenna elements and an RF signal processing network connected to each set of antenna elements. The network has a function, F(Ξ,x)=ΦA(x)−ΦB(x)+ΦC(x)−ΦD(x) . . . +ΦN−1(x)−ΦN(x), where x is a signal, ΦA(x) is the phase angle of signal x at the first element set, ΦB(x) is the phase angle of signal x at the second element set, ΦN(x) is the phase angle of signal x at the set N, and Ξ contains all additional parameters which bear on the system. The network is configured to pass a signal for which F(Ξ,x)>ε, where ε is a threshold amount, such that the antenna has gain to signals within a radius and has attenuation outside the radius.

Inventors:

Althouse, Mark L. G.

Patent Number:

Technical domain:

Communications

FIle Date:

2007-09-19

Grant Date:

2010-01-05

Grant time:

839 days

Grant time percentile rank:

15

Claim count percentile rank:

6

Citations percentile rank:

1

'Cited by' percentile rank:

1

Assignee:

NATIONAL SECURITY AGENCY