Electro-optically controlled wideband multi-beam phased array antenna
First Claim
1. In a radiant energy receiving system, the combination comprising;
- a plurality of N antenna elements for producing radio frequency (RF) signals of different phases as a function of an angle of inclination of the same wavefront of an electromagnetic wave;
N sets of an RF amplifier and a light modulator connected in succession from each respective one of said antenna elements, each modulator including a laser for producing a light output intensity modulated in accordance with the RF signal appearing at the output of the amplifier connected thereto;
first, second, third . . . Nth optical dividers connected from respective ones of said modulators;
a beam port corresponding to each one of a plurality of M different wavefront angles;
receiver means connected from each beam port;
a light intensity demodulator connected to each beam port;
first, second, third . . . Mth optical combiners connected to respective ones of said light intensity demodulators, each optical divider having a set of first, second, third . . . Mth optical fibers connected thereform, said first, second, third . . . Mth optical fibers of said first optical divider being connected from said first optical divider to said first, second, third . . . Mth optical combiners, respectively;
said first, second, third . . . Mth optical fibers of said second optical divider being connected from said second optical divider to said first, second, third . . . Mth optical combiners, respectively;
said first, second, third . . . Mth optical fibers connected from said third optical divider to said first, second, third . . . Mth optical combiners, respectively, . . . said Nth optical divider having first, second, third . . . Mth optical fibers connected therefrom to said first, second, third . . . Mth optical combiners, respectively;
all of said first optical fibers having lengths different from each other, all of said second optical fibers having lengths different from each other, all of said third optical fibers having lengths different from each other, . . . and all of said Mth optical fibers having lengths different from each other;
said optical fibers having lengths chosen to cause signals appearing at one of said first, second, third . . . Mth beam ports to arrive simultaneously and be in phase for received plane waves of first, second, third . . . Mth beam angles, respectively.
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Accused Products
Abstract
An optical network (46) for providing a wideband, true time delay phased antenna array (100) with simultaneous multiple beam capability is disclosed. The network (46) is provided for connection between plural beam ports (48-52M) and plural antenna elements (20-24N) for converting a received radio frequency (RF) planar wavefront (10) to plural in-phase signals at one and only one beam port (48-52M) for each respective one of a plurality of directions of wave propagation. The converse is true for a transmitted wave. The network (46) includes a laser (30-34N) for each antenna element (20-24N) or each beam port (48-52N) modulated by RF energy which is separated and delayed via optical dividers (35-39N) connected to optical combiners (40-44M) by optical fibers (46) of different lengths. Substantially all signals then arrive in-phase at one particular beam port (48-52M) for a receiver (56-60M) receiving a wave at one particular corresponding angle. In transmitted waves, appropriate radiations from the phased array ( 400) differ by an amount to effect transmission in one particular direction corresponding to the beam port (208-212M) selected for energization by the transmitter (218).
135 Citations
21 Claims
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1. In a radiant energy receiving system, the combination comprising;
- a plurality of N antenna elements for producing radio frequency (RF) signals of different phases as a function of an angle of inclination of the same wavefront of an electromagnetic wave;
N sets of an RF amplifier and a light modulator connected in succession from each respective one of said antenna elements, each modulator including a laser for producing a light output intensity modulated in accordance with the RF signal appearing at the output of the amplifier connected thereto;
first, second, third . . . Nth optical dividers connected from respective ones of said modulators;
a beam port corresponding to each one of a plurality of M different wavefront angles;
receiver means connected from each beam port;
a light intensity demodulator connected to each beam port;
first, second, third . . . Mth optical combiners connected to respective ones of said light intensity demodulators, each optical divider having a set of first, second, third . . . Mth optical fibers connected thereform, said first, second, third . . . Mth optical fibers of said first optical divider being connected from said first optical divider to said first, second, third . . . Mth optical combiners, respectively;
said first, second, third . . . Mth optical fibers of said second optical divider being connected from said second optical divider to said first, second, third . . . Mth optical combiners, respectively;
said first, second, third . . . Mth optical fibers connected from said third optical divider to said first, second, third . . . Mth optical combiners, respectively, . . . said Nth optical divider having first, second, third . . . Mth optical fibers connected therefrom to said first, second, third . . . Mth optical combiners, respectively;
all of said first optical fibers having lengths different from each other, all of said second optical fibers having lengths different from each other, all of said third optical fibers having lengths different from each other, . . . and all of said Mth optical fibers having lengths different from each other;
said optical fibers having lengths chosen to cause signals appearing at one of said first, second, third . . . Mth beam ports to arrive simultaneously and be in phase for received plane waves of first, second, third . . . Mth beam angles, respectively. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
- a plurality of N antenna elements for producing radio frequency (RF) signals of different phases as a function of an angle of inclination of the same wavefront of an electromagnetic wave;
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14. In a radiant energy transmitting system, the combination comprising:
- a plurality of N antenna elements for radiating electromagnetic waves at first, second, third . . . Mth angles of radio frequency (RF) signals;
N sets of an amplifier and a light intensity demodulator connected in succession to each respective one of said antenna elements;
first, second, third . . . Nth optical combiners connected to respective ones of said demodulators;
a beam port respectively corresponding to each one of said plurality of M different wavefront angles;
transmitter means connected to each beam port;
a light intensity modulator connected from each beam port;
first, second, third . . . Mth optical dividers connected from respective ones of said light intensity modulators, each optical divider having a set of first, second, third . . . Nth optical fibers connected therefrom;
said first, second, third . . . Nth optical fibers of said first optical divider being connected from said first optical divider to said first, second, third . . . Nth optical combiners, respectively;
said first, second, third . . . Nth optical fibers of said second optical divider being connected from said second optical divider to said first, second, third . . . Nth optical combiners, respectively;
said first, second, third . . . Nth optical fibers connected from said third optical divider to said first, second, third . . . Nth optical combiners, respectively, . . . said Mth optical divider having first, second, third . . . Nth optical fibers connected therefrom to said first, second, third . . . Nth optical combiners, respectively, all of said first optical fibers having lengths different from each other, all of said second optical fibers having lengths different from each other, all of said third optical fibers having lengths different from each other, . . . and all of said Nth optical fibers having lengths different from each other;
said optical fibers having lengths chosen to cause signals applied at one of said first, second, third . . . Mth beam ports to be translated into signals at said antenna elements to product plane waves propagated at said first, second, third . . . Mth angles, respectively. - View Dependent Claims (15, 16)
- a plurality of N antenna elements for radiating electromagnetic waves at first, second, third . . . Mth angles of radio frequency (RF) signals;
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17. In a radiant energy receiving and transmitting system, the combination comprising:
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a plurality of "N" antenna elements for providing radio frequency signals of different phases as a function of an angle of inclination of the same wavefront of an electromagnetic wave and for radiating electromagnetic waves at a first, second, third . . . Mth angles of radio frequency signals; a plurality of "N" sets of a first amplifier and a first light modulator connected in succession from each respective one of said plurality of antenna elements, each modulator including a laser for producing a light output intensity modulated in accordance with the radio frequency signal appearing at the output of the amplifier connected thereto; a plurality of "N" sets of a second amplifier and a first intensity demodulator connected in succession to each respective one of said plurality of antenna elements; a plurality of first, second, third . . . Nth optical divider-combiners connected from respective ones of said first light modulators and demodulators for dividing and combining said modulated light; a plurality of "M" beam ports for receive and "M" beam ports for transmit with each beam port corresponding to one of a plurality of "M" different radiant wavefront angles; a receiver means connected from each receive beam port for receiving said radio frequency signals and a transmitter means connected to each transmit beam port for transmitting said radio frequency signals; a plurality of second light intensity demodulators, each second demodulator connected to one of said plurality of receive beam ports for demodulating said radio frequency signals and a plurality of second light intensity modulators, each second modulator connected to one of said plurality of transmit beam ports for modulating said radio frequency signals; a plurality of first, second, third . . . Mth optical combiner-dividers connected to respective ones of said second light intensity demodulators and said second light intensity modulators for dividing and combining said modulated light;
said plurality of optical divider-combiners having a set of first, second, third . . . Mth optical fibers connected therefrom;
said first, second, third . . . Mth optical fibers of said first optical divider-combiner being connected from said first optical divider-combiner to said first, second, third . . . Mth optical combiner-dividers, respectively;
said first, second, third . . . Mth optical fibers of said second optical divider-combiner being connected from said second optical divider-combiner to said first, second, third . . . Mth optical combiner-dividers, respectively;
said first, second, third . . . Mth optical fibers connected from said third optical divider-combiner to said first, second, third . . . Mth optical combiner-dividers, respectively;
. . . said Nth optical divider-combiner having first, second, third . . . Mth optical fibers connected therefrom to said first, second, third . . . Mth optical combiner-dividers, respectively;
all of said first, second, third . . . Mth optical fibers having lengths different from each other;
said optical fibers having lengths chosen for appropriate time delays to cause signals appearing at one of said first, second, third . . . Mth beam ports to be in time and phase synchronism for received plane waves of first, second, third . . . Mth angles, respectively. - View Dependent Claims (18, 19, 20, 21)
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Specification