Adaptive array antenna system

• US 6,735,182 B1
• Filed: 06/19/2000
• Issued: 05/11/2004
• Est. Priority Date: 11/19/1998
• Status: Expired due to Term

• Current Assignee: Nippon Telegraph and Telephone Corporation
• Original Assignee: Nippon Telegraph and Telephone Corporation
• Inventors: Cho, Keizo, Takatori, Yasushi, Nishimori, Kentaro, Hori, Toshikazu
• Primary Examiner(s): HO, DUC CHI
• Application Number:
  US09/581,512
• Time in Patent Office: 1,422 Days
• Field of Search: 370/276, 370/280, 370/294, 370/328, 370/334, 455/69, 455/562.1, 342/367, 342/372
• US Class Current: 370/294
• CPC Class Codes: H01Q 3/26 varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture H01Q3/12, H01Q3/22, H01Q3/24 take precedence
• CPC Class Codes: H01Q 3/2605 Array of radiating elements provided with a feedback control over the element weights, e.g. adaptive arrays
• CPC Class Codes: H01Q 3/267 Phased-array testing or checking devices

Abstract

In an array antenna used in a transceiver in a time division communication system such as TDD (Time Division Duplex) system, amplitude and phase of each antenna element are calibrated in a transceiver itself during actual communication without using external information. A first transmitter (1-3-1) has means (1-5-1) to send a transmit signal to an antenna element (1-1-1) as well as to at least one of the receivers (1-4-1 through 1-4-N). Other transmitter (1-3-2 through 1-3-k) except the first transmitter has means (1-5-k) which sends a transmit signal to a related antenna element (1-1-2 through 1-1-k) as well as to a first receiver (1-4-1) which relates to the first transmitter. Amplitude/phase value obtained in the first receiver (1-4-1) and amplitude/phase values obtained in other receivers (1-4-2 through 1-4-k) except the first receiver provide weighted amplitude/phase values of each antenna elements according to desired desired radiation pattern.

Claims

1. An adaptive array antenna system comprising;

N (N=>

2, N is an integer) number of antenna elements (1-1-1 through 1-1-N),

N number of transmitters (1-3-1 through 1-3-N),

N number of receivers (1-4-1 through 1-4-N),

a directivity calculation circuit (1-7) for controlling radiation pattern of said adaptive antenna system by weighting amplitude and phase of signals applied to a respective receiver related to each antenna element, and combining weighted signals,

said adaptive array antenna being used in Time Division Duplex communication system,

each transmitter being coupled with a related antenna element during transmit time slot in communication, and having means (1-5-1 through 1-5-N) for sending a part of transmit signal to at least one receiver,

amplitude/phase calibration calculation circuit (1-6) receiving outputs of at least two receivers which receive a signal from a transmitter during transmit time slot, and providing amplitude/phase calibration value of a branch related to said transmitter and said receivers by ratio of outputs of said at least two receivers.

2. An adaptive array antenna system according to claim 1 comprising;

N (N=>

2, N is an integer) number of antenna elements (2-1-1 through 2-1-N),

N number of transmitters (2-3-1 through 2-3-N),

N number of receivers (2-4-1 through 2-4-N),

N number of first switches (2-2-1 through 2-2-N) provided for each antenna element for selectively coupling a respective antenna element either to a respective transmitter or to a respective receiver,

a radiation pattern control calculation circuit (2-10) for controlling radiation pattern of said array antenna by weighting signals applied to each receivers with amplitude and phase, and combining weighted signals,

a weight multiplier circuit (2-11) for multiplying transmit signal and amplitude and phase obtained in said radiation pattern control calculation circuit,

N number of separators (2-5-1 through 2-5-N) provided for each transmitters for coupling an output of a respective transmitter to a respective antenna element and separating a part of transmit signal,

a second switch (2-6) for coupling a signal separated by the first separator (2-5-1) with one of second through N'"'"'th receivers (2-4-2 through 2-4-N),

a third switch (2-7) for coupling signals separated by second through N'"'"'th separators (2-5-2 through 2-5-N) with the first receiver (2-4-1),

fourth switches (2-8-1 through 2-8-N) for coupling an input of each receiver (2-4-i) with either a signal of a respective antenna element (2-1-i) through a respective first switch (2-2-i), or a signal from said second switch (2-6) or said third switch (2-7),

an amplitude/phase calibration value calculation circuit (2-9) for providing amplitude/phase calibration value of each antenna element by using an amplitude value and a phase value obtained in each receivers.

3. An adaptive array antenna system according to claim 2, wherein;

said amplitude/phase calibration value calculation circuit (2-9) provides calibration value of i'"'"'th antenna element by;

separating a signal from first transmitter (2-3-1),

coupling the separated signal with i'"'"'th (2=<

i=<

N, i is an integer) fourth switch (2-8-i) through said second switch (2-6),

obtaining a value (1) at an output of said i'"'"'th receiver (2-4-i) which receives said separated signal through i'"'"'th fourth switch (2-8-i),

separating a signal from i'"'"'th transmitter (2-3-i),

coupling the separated signal with first fourth switch (2-8-1) through said third switch (2-7),

obtaining a value (2) at an output of first receiver (2-4-1) which receives said separated signal from i'"'"'th transmitter (2-4-i), and

providing ratio of (said value (1))/(said value (2)) as calibration value of i'"'"'th branch.

4. An adaptive array antenna system according to claim 1 comprising;

N (N=>

2, N is an integer) number of antenna elements (4-1-1 through 4-1-N),

N number of transmitters (4-3-1 through 4-3-N),

N number of receivers (4-4-1 through 4-4-N),

first switches (4-2-1 through 4-2-N) provided for each antenna element for switching an antenna element (4-1-i) either to a respective transmitter (4-3-i) or to a respective receiver (4-4-i),

a radiation pattern control calculation circuit (4-10) for controlling radiation pattern of said adaptive array antenna system by weighting amplitude and phase of a signal applied to each receivers and combining weighted values,

a weight multiplier circuit (4-11) for multiplying transmit signal, and amplitude and phase obtained in said radiation pattern control calculation circuit,

N number of separators (4-5-1 through 4-5-N) for separating an output of each transmitter into two signals,

(N−

2) number of second switches (4-6-2 through 4-6-(N−

1)) for connecting an input of k'"'"'th receiver (4-4-k) either to (k−

1)'"'"'th separator (4-5-k) (2<

=k<

=N−

1, k is an integer) or to (k+1)'"'"'th separator (4-5-(k+1)),

(N−

2) number of third switches (4-7-2 through 4-7-(N−

1)) for connecting k'"'"'th separator (4-5-k) either to an input of (k−

1)'"'"'th receiver (4-4-(k−

1)) or an input of (k+1)'"'"'th receiver (4-4-(k+1)),

fourth switches (4-8-1 through 4-8-N) for connecting an input of a respective receiver (4-4-i) either to a respective antenna element (4-1-i) through one (4-2-i) of said first switches, or to a signal from said second switch (4-6-i) or said third switch (4-7-i),

an amplitude/phase calibration value calculation circuit (4-9) for providing amplitude/phase calibration value of each antenna element by using an amplitude value and a phase value obtained in each of said receivers.

5. An adaptive array antenna system according to claim 4, wherein;

said amplitude/phase calibration value calculation circuit (4-9) calculates;

6. An adaptive array antenna system according to claim 1 comprising;

N (N=>

2, N is an integer) number of antenna elements (6-1-1 through 6-6-N),

N number of transmitters (6-3-1 through 6-3-N),

N number of receivers (6-4-1 through 6-4-N),

first switches (6-2-1 through 6-2-N) for switching each antenna element (6-1-i) either to a respective transmitter (6-3-i) or to a respective receiver (6-4-i),

a radiation pattern control calculation circuit (6-10) for controlling radiation pattern of said adaptive array antenna system by weighting amplitude and phase of a signal applied to each receivers and combining weighted values,

a weight multiplier circuit (6-11) for multiplying transmit signal, and amplitude and phase obtained in said radiation pattern control calculation circuit,

N number of separators (6-5-1 through 6-5-N) provided for each transmitters for separating an output signal of each transmitter,

a second switch (6-6) for connecting a signal from a first separator (6-5-1) to one of first through N'"'"'th receivers (6-4-1 through 6-4-N),

a third switch (6-7) for connecting an input of a first receiver (6-4-1) to one of first through N'"'"'th separators (6-5-1 through 6-5-N),

N number of fourth switches (6-8-1 through 6-8-N) for connecting an input of a respective receiver (6-8-i) either to a first antenna element (6-1-1) through a first switch (6-2-1), or to a signal from a second switch (6-6) or a third switch (6-7),

an amplitude/phase calibration value calculation circuit (6-9) for providing amplitude/phase calibration value of each antenna element by using an amplitude value and a phase value obtained in each receivers.

7. An adaptive array antenna system according to claim 6, wherein;

said amplitude/phase calibration value calculation circuit (6-9) provides calibration value of i'"'"'th antenna element by;

separating a signal from a first transmitter (6-3-1) by using a first separator (6-5-1),

coupling the separated signal with i'"'"'th (1<

=i<

=N, i is an integer) fourth switch (6-8-i) through said second switch (6-6),

obtaining a value (1) at an output of i'"'"'th receiver (6-4-i) which receives said separated signal through i'"'"'th fourth switch (6-8-i),

separating a signal from i'"'"'th transmitter (6-3-i) by using an i'"'"'th separator (6-5-i),

coupling the separated signal with first fourth switch (6-8-1) through said third switch (6-7),

obtaining a value (2) at an output of a first receiver (6-4-1) which receives said separated signal from i'"'"'th transmitter (6-3-1) through said first fourth switch (6-8-1), and

providing ratio of (said value (1))/(said value (2)) as calibration value of i'"'"'th antenna element.

8. An adaptive array antenna system according to claim 1, comprising;

N (N>

=2, N is an integer) number of antenna elements (9-1-1 through 9-1-N),

N number of transmitters (9-3-1 through 9-3-N),

N number of receivers (9-4-1 through 9-4-N),

a first switch (9-2-1 through 9-2-N) provided for each antenna elements for switching an antenna element either to a respective transmitter or to a respective receiver,

a radiation pattern control calculation circuit (9-10) for controlling radiation pattern of said adaptive array antenna system by weighting amplitude and phase of a signal applied to each receivers and combining weighted values,

a weight multiplier circuit (9-11) for multiplying transmit signal, and amplitude and phase obtained in said radiation pattern control calculation circuit,

N number of separators (9-5-1 through 9-5-N) provided for each transmitters for separating a signal from a respective transmitter,

a second switch (9-6) for connecting a signal of a first separator (9-5-1) to one of first through N'"'"'th receivers (9-4-1 through 9-4-N),

a third switch (9-7-2 through 9-7-N) for connecting an input of k'"'"'th receiver either from a first separator (9-5-1) or from k'"'"'th (2<

=k<

=N, k is an integer) separator,

N number of fourth switches (9-8-1 through 9-8-N) for connecting an input of a respective receiver to a signal either from a respective antenna element through a respective first switch, or from said second switch or said third switch,

an amplitude/phase calibration value calculation circuit (9-9) for providing amplitude/phase calibration value of each antenna element by using an amplitude value and a phase value obtained in each receivers.

9. An adaptive array antenna system according to claim 8, wherein;

said amplitude/phase calibration value calculation circuit calculates;