Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
354 words
A directivity control antenna system comprising: an antenna unit having first through fourth dipole antennas in which two-terminal variable reactance circuits are respectively connected to a pair of antenna elements and an impedance adjusting capacitor is connected between feed terminals of said pair of antenna elements; a first signal combiner connected to said first and second dipole antennas of said first through fourth dipole antennas, which are disposed opposite to each other, by feed lines of equal length with respect to said first and second dipole antennas for combining signals from said first and second dipole antennas; a second signal combiner connected to said third and fourth dipole antenna of said first through fourth dipole antennas, which are disposed opposite to each other are perpendicular to said first and second dipole antennas, by feed lines of equal length with respect to said third and fourth dipole antennas for combining signals from said third and fourth dipole antennas; tuning control means for supplying a plurality of DC voltages which are different from each other; changeover control means coupled to said tuning control means for selectively supplying said plurality of DC voltages from a first through a fourth output terminal thereof to said first through fourth dipole antennas for control of the reactances of said two terminal variable reactance circuits of said first through fourth dipole antennas so as to control the directivity of said antenna system, said changeover control means being also coupled to said first and second signal combiners for selectively passing output signals from said first and second signal combiners to a fifth and a sixth output terminal thereof; and a third signal combiner coupled at two input terminals thereof to said fifth and sixth output terminals of said changeover control means for outputting, to a receiver, output signals of said first or second signal combiner or combined output signals of said first and second signal combiners, wherein connection of said first and second signal combiners to said third signal combiner via said changeover control means made is by feed lines of equal length with respect to said first and second signal combiners.
Claim 2
Dependent Claim
354 words
A directivity control antenna system comprising: an antenna unit having first through fourth dipole antennas in which two-terminal variable reactance circuits are respectively connected to a pair of antenna elements and an impedance adjusting capacitor is connected between feed terminals of said pair of antenna elements; a first signal combiner connected to said first and second dipole antennas of said first through fourth dipole antennas, which are disposed opposite to each other, by feed lines of equal length with respect to said first and second dipole antennas for combining signals from said first and second dipole antennas; a second signal combiner connected to said third and fourth dipole antenna of said first through fourth dipole antennas, which are disposed opposite to each other are perpendicular to said first and second dipole antennas, by feed lines of equal length with respect to said third and fourth dipole antennas for combining signals from said third and fourth dipole antennas; tuning control means for supplying a plurality of DC voltages which are different from each other; changeover control means coupled to said tuning control means for selectively supplying said plurality of DC voltages from a first through a fourth output terminal thereof to said first through fourth dipole antennas for control of the reactances of said two terminal variable reactance circuits of said first through fourth dipole antennas so as to control the directivity of said antenna system, said changeover control means being also coupled to said first and second signal combiners for selectively passing output signals from said first and second signal combiners to a fifth and a sixth output terminal thereof; and a third signal combiner coupled at two input terminals thereof to said fifth and sixth output terminals of said changeover control means for outputting, to a receiver, output signals of said first or second signal combiner or combined output signals of said first and second signal combiners, wherein connection of said first and second signal combiners to said third signal combiner via said changeover control means made is by feed lines of equal length with respect to said first and second signal combiners.
Claim 3
Dependent Claim
42 words
A directivity control antenna system according to claim 1, wherein said plural DC voltages are obtained from a tuning voltage of said receiver for variably controlling said reactances of said two terminal variable reactance circuits of said first through fourth dipole antennas.
Claim 4
Dependent Claim
60 words
A directivity control antenna system according to claim 1 or 2, wherein said plurality of DC voltages comprise three voltages, and wherein the difference between the highest one of said three voltages and the middle one of said three voltages is equal to difference between the middle one of said three voltages and the lowest one of said three voltages.
Claim 5
Dependent Claim
27 words
A directivity control antenna system according to claims 1 or 2, wherein said antenna elements comprise transmission lines of a zigzag configuration, said lines having distributed inductance.
Claim 6
Dependent Claim
25 words
A directivity control antenna system according to claim 3, wherein said antenna elements comprise transmission lines of a zigzag configuration, said lines having distributed inductance.