Antenna device and antenna adjustment method

1. An antenna device comprising:

a main reflector;

a sub-reflector including sub-reflector panels and having a reflecting surface facing a reflecting surface of the main reflector;

a primary emitter to receive a radio wave reflected by the sub-reflector;

sub-reflector panel drive mechanisms coupled to and configured to drive the corresponding sub-reflector panels; and

a phase calculator to

calculate each of relative phases of element electric-field vectors on an aperture surface corresponding to panel areas of the main reflector that are irradiated with radio waves from the corresponding sub-reflector panels based on a change in received electric-field strength of the radio wave received by the primary emitter during driving of the sub-reflector panel drive mechanisms, and

determine positions of the sub-reflector panels at which a phase distribution on an aperture surface of the main reflector is minimized.

2. The antenna device according to claim 1 , wherein

the phase calculator calculates, using a rotating element electric-field vector method and based on a change in the received electric-field strength of the radio wave received by the primary emitter when the sub-reflector panel drive mechanisms are finely driven, a relative phase of the element electric-field vector corresponding to each of the sub-reflector panels regarded as antenna elements.

3. The antenna device according to claim 1 , wherein

after movement of the main reflector in an elevation direction, the phase calculator calculates the relative phase during driving of the sub-reflector panel drive mechanisms.

4. The antenna device according to claim 3 , further comprising:

an attitude controller to

calculate an approximate curved surface from a shape of the main reflector, and

cause movement of the sub-reflector to a focal position of the curved surface,

wherein after the attitude controller moves the sub-reflector, the phase calculator calculates the relative phase during driving of the sub-reflector panel drive mechanisms.

5. The antenna device according to claim 3 , further comprising:

an attitude controller to

determine a position of the sub-reflector at which the received electric-field strength has a maximum value, and

cause movement of the sub-reflector to the determined position,

wherein after the attitude controller moves the sub-reflector, the phase calculator calculates the relative phase during driving of the sub-reflector panel drive mechanisms.

6. An antenna device comprising:

a main reflector;

a sub-reflector including sub-reflector panels and having a reflecting surface facing a reflecting surface of the main reflector;

a primary emitter to receive a radio wave reflected by the sub-reflector;

sub-reflector panel drive mechanisms coupled to and configured to drive the corresponding sub-reflector panels;

a phase calculator to

calculate a relative phase of an element electric-field vector corresponding to each of the sub-reflector panels based on a change in received electric-field strength of the radio wave received by the primary emitter during driving of the sub-reflector panel drive mechanisms, and

determine positions of the sub-reflector panels at which a phase distribution on an aperture surface of the main reflector is minimized; and

a storage to store position information of positions of the sub-reflector panels that are determined by the phase calculator after moving the main reflector in elevation directions in advance,

wherein the phase calculator determines the positions of the sub-reflector panels based on the position information stored in the storage and an elevation angle of the main reflector.

7. The antenna device according to claim 6 , wherein

the phase calculator calculates, using a rotating element electric-field vector method and based on a change in the received electric-field strength of the radio wave received by the primary emitter when the sub-reflector panel drive mechanisms are finely driven, a relative phase of the element electric-field vector corresponding to each of the sub-reflector panels regarded as antenna elements.

8. The antenna device according to claim 6 , wherein

after movement of the main reflector in an elevation direction, the phase calculator calculates the relative phase during driving of the sub-reflector panel drive mechanisms.

9. The antenna device according to claim 8 , further comprising:

an attitude controller to

calculate an approximate curved surface from a shape of the main reflector, and

cause movement of the sub-reflector to a focal position of the curved surface,

wherein after the attitude controller moves the sub-reflector, the phase calculator calculates the relative phase during driving of the sub-reflector panel drive mechanisms.

10. The antenna device according to claim 8 , further comprising:

an attitude controller to

determine a position of the sub-reflector at which the received electric-field strength has a maximum value, and

cause movement of the sub-reflector to the determined position,

wherein after the attitude controller moves the sub-reflector, the phase calculator calculates the relative phase during driving of the sub-reflector panel drive mechanisms.

11. The antenna device according to claim 6 , further comprising:

one or more focusing reflectors between the sub-reflector and the primary emitter,

wherein the radio wave reflected by the sub-reflector is reflected by the one or more focusing reflectors to focus on a phase center of the primary emitter.

12. An antenna device comprising:

a main reflector;

a sub-reflector including sub-reflector panels and having a reflecting surface facing a reflecting surface of the main reflector;

a primary emitter to receive a radio wave reflected by the sub-reflector;

sub-reflector panel drive mechanisms coupled to and configured to drive the corresponding sub-reflector panels;

a phase calculator to

calculate a relative phase of an element electric-field vector corresponding to each of the sub-reflector panels based on a change in received electric-field strength of the radio wave received by the primary emitter during driving of the sub-reflector panel drive mechanisms, and

determine positions of the sub-reflector panels at which a phase distribution on an aperture surface of the main reflector is minimized; and

one or more focusing reflectors between the sub-reflector and the primary emitter,

wherein the radio wave reflected by the sub-reflector is reflected by the one or more focusing reflectors to focus on a phase center of the primary emitter.

13. The antenna device according to claim 12 , wherein

the phase calculator calculates, using a rotating element electric-field vector method and based on a change in the received electric-field strength of the radio wave received by the primary emitter when the sub-reflector panel drive mechanisms are finely driven, a relative phase of the element electric-field vector corresponding to each of the sub-reflector panels regarded as antenna elements.

14. The antenna device according to claim 12 , wherein

after movement of the main reflector in an elevation direction, the phase calculator calculates the relative phase during driving of the sub-reflector panel drive mechanisms.

15. The antenna device according to claim 14 , further comprising:

an attitude controller to

calculate an approximate curved surface from a shape of the main reflector, and

cause movement of the sub-reflector to a focal position of the curved surface,

wherein after the attitude controller moves the sub-reflector, the phase calculator calculates the relative phase during driving of the sub-reflector panel drive mechanisms.

16. The antenna device according to claim 14 , further comprising:

an attitude controller to

determine a position of the sub-reflector at which the received electric-field strength has a maximum value, and

cause movement of the sub-reflector to the determined position,

wherein after the attitude controller moves the sub-reflector, the phase calculator calculates the relative phase during driving of the sub-reflector panel drive mechanisms.

17. An antenna adjustment method of an antenna device including a main reflector, a sub-reflector including sub-reflector panels, and a primary emitter to receive a radio wave reflected by the sub-reflector, the method comprising:

calculating, based on a change in received electric-field strength of the radio wave received by the primary emitter during changes of positions of the sub-reflector panels, each off relative phases of element electric-field vectors on an aperture surface corresponding to panel areas of the main reflector that are irradiated with radio waves from the corresponding sub-reflector panels; and

determining positions of the sub-reflector panels at which a phase distribution on an aperture surface of the main reflector is minimized.