Antenna apparatus and measurement method
An antenna apparatus 1 includes: an anechoic box 50 having the internal space 51 that is not influenced by the surrounding radio wave environment; a plurality of antennas 6 that use radio signals in a plurality of divided frequency bands set in advance; a reflector 7 that is housed in the internal space and has a predetermined paraboloid of revolution, radio signals transmitted or received by an antenna 110 of a DUT 100 being reflected through the paraboloid of revolution; and antenna arrangement means 60 for sequentially arranging the plurality of receiving antennas 6 at a focal position F, which is determined from the paraboloid of revolution, according to the divided frequency bands.
1. An antenna apparatus, comprising:
an anechoic box having an internal space that is not influenced by a surrounding radio wave environment;
a plurality of antennas corresponding to radio signals in a plurality of divided frequency bands set in advance;
a reflector that is housed in the internal space and has a predetermined paraboloid of revolution, radio signals transmitted or received by an antenna to be tested provided in a device under test being reflected through the paraboloid of revolution; and
antenna arrangement means for sequentially arranging the plurality of antennas at a focal position, which is determined from the paraboloid of revolution, according to the divided frequency bands.
2. The antenna apparatus according to claim 1 ,
wherein the antenna to be tested uses a radio signal in a specified frequency band,
the divided frequency bands are partial frequency bands of a predetermined spurious frequency band from a frequency band lower than the specified frequency band to a frequency band higher than the specified frequency band, and
the anechoic box further includes:
a test antenna that uses a radio signal in the specified frequency band;
a simulation measurement device that outputs a test signal to the device under test through the test antenna, receives a measurement target signal output from the device under test, to which the test signal has been input, through the test antenna, and measures a radio signal in the specified frequency band based on the received measurement target signal; and
a signal analysis device that receives a radio signal in the spurious frequency band, which is output together with the measurement target signal from the device under test to which the test signal has been input, through each of the antennas corresponding to the divided frequency bands and analyzes a frequency distribution and power of the received radio signal in the spurious frequency band.
3. The antenna apparatus according to claim 2 ,
wherein the antenna holding mechanism is provided on a bottom surface of the internal space of the anechoic box, and is formed by the rotating body rotatable along a plane in a vertical direction by the rotary shaft along a horizontal direction.
4. The antenna apparatus according to claim 2 ,
wherein the antenna arrangement means operates automatically, and includes:
an antenna holding mechanism that is provided in the internal space of the anechoic box such that each of the antennas is arranged on a circumference around a rotary shaft in a rotating body rotatable with the rotary shaft as a center, the focal position is located on the circumference, and each of the antennas passes through the focal position by rotation of the rotating body;
a power unit having a driving motor for rotationally driving the rotating body through the rotary shaft; and
an automatic antenna arrangement control unit that controls the driving motor such that each of the antennas is sequentially stopped at the focal position according to the divided frequency bands.
5. The antenna apparatus according to claim 2 ,
wherein the antenna arrangement means includes:
an antenna holding mechanism that has a first slide mechanism that holds a plurality of antenna pedestals, on which the antennas are provided, so as to be slidable in one direction while maintaining a predetermined interval and a second slide mechanism that slidably holds the first slide mechanism in the other direction perpendicular to the one direction through a pedestal portion and that is provided in the internal space of the anechoic box such that each of the antennas is able to pass through the focal position;
a power unit that includes a first driving motor for rotationally driving a first driving shaft for sliding each of the antenna pedestals in the one direction and a second driving motor for rotationally driving a second driving shaft for sliding the pedestal portion in the other direction; and
an automatic antenna arrangement control unit that controls the first and second driving motors such that each of the antennas is sequentially stopped at the focal position according to the divided frequency bands.
6. The antenna apparatus according to claim 1 ,
wherein the antenna arrangement means operates automatically, and includes:
an antenna holding mechanism that is provided in the internal space of the anechoic box such that each of the antennas is arranged on a circumference around a rotary shaft in a rotating body rotatable with the rotary shaft as a center, the focal position is located on the circumference, and each of the antennas passes through the focal position by rotation of the rotating body;
a power unit having a driving motor for rotationally driving the rotating body through the rotary shaft; and
an automatic antenna arrangement control unit that controls the driving motor such that each of the antennas is sequentially stopped at the focal position according to the divided frequency bands.
7. The antenna apparatus according to claim 6 ,
wherein the antenna holding mechanism is provided on a bottom surface of the internal space of the anechoic box, and is formed by the rotating body rotatable along a plane in a horizontal direction by the rotary shaft along a vertical direction.
8. The antenna apparatus according to claim 7 ,
wherein the antenna holding mechanism holds each of the antennas such that a receiving surface of each of the antennas is directed to the rotary shaft side.
9. The antenna apparatus according to claim 7 ,
wherein the antenna holding mechanism holds each of the antennas such that a receiving surface of each of the antennas is directed to an opposite side to the rotary shaft side.
10. The antenna apparatus according to claim 7 ,
wherein, in a case where each of the antennas is stopped at the focal position, the antenna holding mechanism holds the antenna so as to face the reflector at an angle at which a receiving surface of the antenna is perpendicular to a beam axis of the radio signal.
11. The antenna apparatus according to claim 6 ,
wherein the antenna holding mechanism holds each of the antennas such that a receiving surface of each of the antennas is directed to the rotary shaft side.
12. The antenna apparatus according to claim 11 ,
wherein, in a case where each of the antennas is stopped at the focal position, the antenna holding mechanism holds the antenna so as to face the reflector at an angle at which a receiving surface of the antenna is perpendicular to a beam axis of the radio signal.
13. The antenna apparatus according to claim 6 ,
wherein the antenna holding mechanism holds each of the antennas such that a receiving surface of each of the antennas is directed to an opposite side to the rotary shaft side.
14. The antenna apparatus according to claim 13 ,
wherein, in a case where each of the antennas is stopped at the focal position, the antenna holding mechanism holds the antenna so as to face the reflector at an angle at which a receiving surface of the antenna is perpendicular to a beam axis of the radio signal.
15. The antenna apparatus according to claim 6 ,
wherein, in a case where each of the antennas is stopped at the focal position, the antenna holding mechanism holds the antenna so as to face the reflector at an angle at which a receiving surface of the antenna is perpendicular to a beam axis of the radio signal.
16. The antenna apparatus according to claim 1 ,
wherein the antenna arrangement means includes:
an antenna holding mechanism that has a first slide mechanism that holds a plurality of antenna pedestals, on which the antennas are provided, so as to be slidable in one direction while maintaining a predetermined interval and a second slide mechanism that slidably holds the first slide mechanism in the other direction perpendicular to the one direction through a pedestal portion and that is provided in the internal space of the anechoic box such that each of the antennas is able to pass through the focal position;
a power unit that includes a first driving motor for rotationally driving a first driving shaft for sliding each of the antenna pedestals in the one direction and a second driving motor for rotationally driving a second driving shaft for sliding the pedestal portion in the other direction; and
an automatic antenna arrangement control unit that controls the first and second driving motors such that each of the antennas is sequentially stopped at the focal position according to the divided frequency bands.
17. The antenna apparatus according to claim 16 ,
wherein a plurality of the first slide mechanisms are provided so as to be parallel to the one direction and be spaced apart from each other by a predetermined distance in the other direction, and
the power unit includes the first driving motor corresponding to each of the first slide mechanisms.