JPH0262970A - Holding device for antenna to be measured - Google Patents

Abstract

PURPOSE:To measure a radiation pattern over a wide solid-angle range by providing a holder and a rotary mechanism. CONSTITUTION:When a body 1 to be measured receives an electromagnetic wave sent by an antenna 5 for measurement, the rotary mechanism 4 varies the angle of the body 1 to be measured and measures the reception intensity of the body 1 to be measured to check reception pattern characteristics of the antenna as the body 1 to be measured. Further, the holder 2 is a spherical shell which is made of a nonmetallic material and has an axis 3A as its major axis, the body 1 to be measured is held by a support part 2A nearby the center of the cavity part of the spherical shell, and the mechanism 4 blows force feed air which is inputted from a spiral air hose 4A out of the blowout hole of a holder receiving pan 4C above a perpendicular axis 4B to rotate the holder 2 around the axis 3A. Further, the mechanism 4 is mounted on the rotary disk 6A of a rotary seat 6 and rotated around the axis 3B. Then the force feed air is inputted from the hose 4A and deforms following up the rotation of the rotary disk 6A. Further, the height of the perpendicular axis 4B is increased so as to evade the influence of electromagnetism generated by the motor driving of the rotary seat 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is utilized for testing antennas for wireless communication devices. It is particularly suitable for testing small antennas such as antennas for portable wireless communication devices in an anechoic chamber.

The present invention relates to an apparatus for holding an antenna to be measured in order to measure the radiation characteristics of the antenna over a large azimuthal angle.

[Conventional technology]

The structure of the conventional device is shown in FIG. 7(a). The antenna to be measured 31A is held by a holder 32, and this holder 32 is attached to a rotation mechanism 33 in the angle of attack direction.

The rotating mechanism 33 includes a rotating shaft 33A1, a door-shaped gear 33C fixed to the rotating shaft 33A and driven by a motor 33B, and a table 33D rotatably supporting the rotating shaft 33A. Since the door-shaped gear 33C is connected to the holder 32, the angle of attack of the central axis 31B of the antenna to be measured 31A held by the holder 32 changes due to the rotation of the rotating shaft 33A.

The rotation mechanism 33 is attached to a horizontal rotation mechanism 34 via a table 33D. In the horizontal rotation mechanism 34, a vertical shaft 34B inside a housing 34A is rotated by a motor 34C via a gear, and the vertical shaft 34B is rotated by a key 3.
It is connected to the above-mentioned stand 33D by 4D.

In this way, it is capable of rotational movement around one or more rotation axes 33A, 34B, and allows the antenna to be measured 31 to receive electromagnetic waves transmitted from another measurement antenna 35 placed far away. The radiation pattern of the antenna to be measured is measured by receiving or transmitting electromagnetic waves from the antenna to be measured 31 using the measurement antenna 35 . Here, the main part that firmly holds or rotates the antenna to be measured is generally made of a highly rigid material such as metal or reinforced plastic. A center of rotation 37 is created by the two rotation axes (33A, 34B).

[Problem that the invention seeks to solve]

However, in such conventional devices, the rotation around the horizontal axis is generally limited to within ±90°, making it difficult to measure the radiation pattern over the entire solid angle.

In addition, because the main parts such as the holder and rotation mechanism are made of materials such as metal or reinforced plastic that have electromagnetic wave transmittance of 0 or less than 1,
When the object to be measured is smaller than the measuring device, there is a drawback that the error in the antenna radiation pattern increases due to the influence of reflection, shielding, scattering, etc. of electromagnetic waves by these main parts.

In particular, there is an extremely large error in measuring the radiation pattern in the area hidden by the rotating mechanism when viewed from the antenna to be measured. especially,
This becomes a serious problem for relatively small antennas under test where energy is radiated over a wide range of solid angles.

For this reason, as shown in FIG. 7(b), the antenna to be measured 31C is held apart from the main parts made of the above-mentioned metal etc. using a member 36 having high electromagnetic wave transmittance such as foamed resin. However, even with this method, it is difficult to measure over the entire solid angle. In addition, in the method shown in Figure 7, etc.
Although the effects of reflection and scattering of electromagnetic waves from the main parts are reduced, the center of rotational movement and the antenna under test are separated from each other, so the distance between the antenna under test and the measurement antenna changes depending on the rotation. However, this method still has the disadvantage of causing errors in the measured radiation pattern.

SUMMARY OF THE INVENTION An object of the present invention is to solve these drawbacks and provide a holding device for an antenna to be measured that can measure a radiation pattern over a wide solid angle range without interference such as reflection or scattering from the main part. do.

[Means for solving problems]

The present invention provides a holding device for an antenna to be measured, which includes a holder for holding an object to be measured including an antenna, and a rotation mechanism for rotating the angle at which the object to be measured is held together with the holder in a desired direction. , the holder is a rotationally symmetrical body made of a nonmetallic material with high electromagnetic wave transmittance, and has a structure that holds the object to be measured near the center of symmetry, and the rotation mechanism holds the rotationally symmetrical body near the center of symmetry. It is characterized by a structure that allows it to rotate around.

This rotationally symmetrical holder is made of foamed resin, for example.
Alternatively, it is better to use a thin cocoon-like structure made of non-metallic rods or threads, or a transparent shell-like structure.

[Effect]

The holder that holds the antenna to be measured has a line-symmetric shape, holds the antenna to be measured near the center of symmetry, and generates rotational movement around the center of symmetry by a rotation mechanism. Therefore, the antenna to be measured can be rotated over the entire solid angle, and measurements can be made at each angle.

The material of the holder has high electromagnetic wave transmittance. Therefore, it hardly affects the electromagnetic waves arriving from a distance or the electromagnetic waves projected by the antenna to be measured.

The space inside this holder is large enough to accommodate the antenna to be measured. Therefore, since any of the main parts of the rotation mechanism that rotates the holder are far away from the radiation path connecting the measurement antenna and the antenna to be measured, these main parts do not affect electromagnetic waves.

Specifically, rotationally symmetrical objects include a perfect round sphere, a spheroid,
Including things such as cylindrical bodies.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory diagram showing the configuration of a first embodiment of the present invention.

In this figure, the first embodiment of the holding device for the antenna under test includes a holder 2 that holds the object 1 to be measured including the antenna by a support section 2A, and an angle at which the object 1 is held by the holder 2. A rotation mechanism 4 is provided for rotating the shafts 3A and 3B in respective directions.

Reference numeral 5 is a measurement antenna installed at a far position on the axis 3A. When the measured object 1 receives the electromagnetic waves sent out by the measurement antenna 5, the angle of the measured object 1 is rotated and changed by the rotation mechanism 4, and the reception intensity of the measured object 1 is measured. Examine the reception pattern characteristics of the antenna. Further, similar measurements are performed by transmitting electromagnetic waves from the object to be measured 1 and receiving them by the measuring antenna 5.

Here, the feature of the present invention is that the holder 2 is an elliptical rotationally symmetrical spherical shell made of foamed resin, which is a non-metallic material, and has a long shaft 3A, and the object 1 to be measured is the spherical shell. The rotating mechanism 4 blows out the pressurized air input from the spiral air hose 4A from the outlet of the holder tray 4C on the upper part of the upright shaft 4B, and rotates the holder 2 near the center of the hollow part of the shell. is rotated around the axis 3A.

This rotating mechanism 4 is further placed on a rotating seat 60 and a rotating disk 6A, and is rotated around the shaft 3B.

This rotary seat 6 is configured to rotate a rotary disk 6A by driving a motor. The above-mentioned pressurized air is manually supplied from the spiral air hose 4A, and is deformed following the rotation of the rotary disk 6A. In order to avoid electromagnetic effects caused by the motor drive of the rotary seat 6 during testing of the object to be measured, the height of the upright shaft 4B is increased.

However, if more precise measurement is required, the drive of the rotary disk 6A of the rotary seat may be changed as shown in FIG.
This is done by blowing pressurized air from an air nozzle 6D onto the guide vane 6C provided at the lower part of the rotating shaft 6B of A. In addition, in FIG. 2, reference numeral 4D is an air outlet provided in the holder tray 4C, and from here the holder 2 is slightly floated by the air flow shown by arrow A, and the air flow from the two outlets is It can be rotated in any direction around the axis 3A by adjusting. These are made of electromagnetically unaffected materials. A rotationally symmetrical shape is made of foamed resin, and a cavity is provided in the center to accommodate the object to be measured. This cavity is provided with a lid made of the same material as the holder, or the holder 2 itself is structured so that it can be divided into multiple parts, so that the cavity can be exposed. It can be easily taken in and out from the outside.

When the object to be measured is integrated with a radio device, it is appropriate to use the radio device as a transmitter or receiver for measurement. If the object to be measured is a single antenna, a small transmitter with a built-in power supply is housed together with the antenna to be measured, and this is connected to the antenna to be measured.

In the case of such a rotation mechanism, it is more suitable for the holder 2 to have a shape such as a spheroid or a cylinder in which the axis of rotation is uniquely determined, rather than a true sphere. The rotation angle around this axis 3A can be measured by attaching a suitable mark to the surface of the holder 2 and reading it optically.

Also, the angle of rotation about axis 3B can be easily measured with an optical, magnetic or electrical encoder.

FIG. 3 is an explanatory diagram of a second embodiment of the present invention. In this embodiment, the holder 12 has a cylindrical rotationally symmetrical shape, and the holder 12 is located approximately at the center of its hollow interior, as indicated by a broken line. The object to be measured 1 is held by a support part (not shown).

This holder 12 is held by a pair of rollers 13 so as not to come into contact with the underframe 14. A belt seat 12A on which a bell 14A is hung is provided approximately at the center of the holder 12, and the belt 14A is guided by a roller 14B inside the underframe 14.

In this embodiment, the holder 2 is a molded product made of foamed resin, and has high electromagnetic wave transmittance. Similarly, the belt 14A is made of a material with high electromagnetic wave transmittance.

FIG. 4 is an explanatory view of the drive of this embodiment, in which a bell 14A hung on the holder 12 is driven by a DC motor 14C provided inside the underframe 14. Therefore, the retainer 12
is supported by rollers 13 and rotates around axis 3A.

The underframe 14 is rotated around the shaft 3B by a DC motor 15A in the lower housing 15. Any of these DC motors can also be an air motor.

FIG. 5 is an explanatory diagram of a third embodiment of the present invention. In this embodiment, the holder 22 has a rotationally symmetrical shape of a perfect circle and holds the object 1 to be measured. This holder 22 is supported by a rotating shaft 23 equipped with a motor 23A, each outer end of this rotating shaft 23 is rotatably attached to a circular ring 24, and this circular ring 24 is supported by a roller 24A. ing.

In FIG. 5, the means for applying rotational force to the roller 24A and the means for preventing the circular ring 24 from coming off the roller 24A are omitted.

That is, the holder 22 is rotated around the shaft 3B by the motor 23A, and the holder 22 is rotated around the shaft 3A by the rotation of the circular ring 24 by the roller 24A.

FIG. 6 is a diagram showing another form of the holding structure of the holder.

In this figure, a structure made of non-metallic rods, threads, plates, or a combination of these, whose outer shell is thin or transparent to electromagnetic waves, and whose interior is as close to hollow as possible, with a true spherical hollow rotational symmetry. The object to be measured 1 is held inside by a member 7A such as a thread or a rod.

A holder with this structure also has high electromagnetic wave transmittance, similar to the holder made of foamed resin.

〔Effect of the invention〕

As described above, according to the present invention, it becomes easy to measure a radiation pattern over the entire solid angle, and the influence of reflection and scattering from the rotating mechanism on antenna radiation pattern measurement can be sufficiently reduced.

Furthermore, since the distance between the object to be measured and the measurement antenna is always kept substantially constant, measurement errors due to changes in distance do not occur. In particular, it is possible to reduce errors associated with measuring the radiation pattern of small antennas used in portable radio equipment, etc., which are susceptible to reflection and scattering from rotating mechanisms, or antennas integrated with such radio equipment. . Therefore, it is possible to realize a holding device for the antenna to be measured which has a relatively simple structure and good measurement performance.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a first embodiment of the present invention. FIG. 2 is an explanatory diagram of the rotation mechanism of the above embodiment. FIG. 3 is an explanatory diagram of a second embodiment of the present invention. FIG. 4 is a drive explanatory diagram of the above embodiment. FIG. 5 is an explanatory diagram of a third embodiment of the present invention. FIG. 6 is a diagram showing another form of the holder. FIG. 7 is a diagram showing a conventional example. 1... Object to be measured, 2.12.22.32... Holder, 2A... Support part, 3A, 3B... Shaft, 4.33.
34...Rotation mechanism, 4A...Spiral air hose, 4B...Upright shaft, 4C...Holder saucer, 4D...
- Air outlet, 5.35...Measuring antenna, 6...Rotary seat, 6A...Rotary plate, 6B. 23.33A, 34B... Rotating shaft, 6C... Guide vane, 6D... Air nozzle nope 7... Outer shell of holder, 7
A... Member, 12A... Belt seat, 13.14B,
24A...roller, 14...underframe, 14A...bell +-114C, 15A...DC motor, 15...
Lower housing, 24... Circular ring, 31A... Antenna to be measured, 31B... Central axis, 33B, 34C... Motor, 33C... Door-shaped gear, 33D... Stand, 37.
...The center of rotational movement. Patent Applicant Nippon Telegraph and Telephone Corporation Agent Patent Attorney Nao Ide

Claims (1)

[Claims] 1. An antenna to be measured that includes a holder that holds an object to be measured including an antenna, and a rotation mechanism that rotates the angle at which the object to be measured is held together with the holder in a desired direction. In the holding device, the holding tool is a rotationally symmetrical body formed of a non-metallic material with high electromagnetic wave transmittance, and has a structure that holds the object to be measured near the center of symmetry, and the rotating mechanism is configured to hold the object to be measured near the center of symmetry. A holding device for an antenna to be measured, characterized in that it has a structure in which a rotationally symmetrical body is rotated around a center of symmetry.