JP3610151B2 - mobile phone - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain communication with excellent sensitivity and to ensure a long speech time by using an antenna turn device to direct the direction of a circularly polarized wave antenna providing an excellent directivity into a flying direction of a satellite. SOLUTION: A circularly polarized antenna section is turned in a direction of providing an excellent radiation characteristic to allow the user of a portable telephone set to make comfortable communication without notifying an azimuth of a flying satellite. Thus, a geared rotary connector 31 is provided between the antenna and a radio equipment circuit section and the antenna side is turned by an electric motor (e.g. a stepping motor) 32 or the like. In order to control the rotary angle of the antenna, a rotary angle control means 42 controls the number of revolutions of the electric motor 32 provided with the gear 32a so as to maximize the reception signal based on a detection signal from the reception signal intensity detector 41. The antenna is driven in this way to direct the direction offering the beast antenna directivity to an azimuth of the flying of an orbital satellite.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mobile phone provided with a satellite tracking antenna effective for satellite communication using an orbiting satellite.
[0002]
[Prior art and its problems]
In recent years, mobile phones using orbiting satellites orbiting the earth in medium or low orbit have been proposed by various companies, and those frequency bands are 1.6 GHz from the ground mobile phone to the satellite. A 2.4 GHz band is allocated from the mobile phone to the ground mobile phone, and the 1.6 GHz band is also allocated as a frequency band used for bidirectional communication from the ground to the satellite and from the satellite to the ground. As an antenna configuration, for example, as shown in FIG. 4, a folding antenna array 204 using a transmitting microstrip line planar antenna 202 and a receiving microstrip line planar antenna 203 for satellite communication (an ITU research world non-stationary satellite communication system No. 261 / 262 New Japan ITU Association August 1993 P.36) is attached to the cellular phone 201, and the antenna is directed toward the orbiting satellite by adjusting the folding angle α of the folding antenna array 204. However, it is difficult to align the orientation of the antenna array 204 in the direction in which the orbiting satellite is flying, and for the best communication, the user should match the best direction of the radiation pattern of the antenna array 204 with it. If you don't rotate with your phone No et al.
[0003]
[Means for Solving the Problems]
The cellular phone of the present invention includes a circularly polarized antenna rotating means for transmitting and receiving for satellite communication, a received signal strength detecting means, and an antenna rotation angle control means.
[0004]
DETAILED DESCRIPTION OF THE INVENTION
To solve the problems described above, and properly position the helical antenna or a microstrip line planar antenna for circularly polarized wave in mobile phones (hereinafter referred to as plane antenna) to the mobile phone, by rotating the antenna, antenna directivity The first surface (front surface) and the second surface (rear surface) facing each other are aimed at improving communication quality by directing the best direction to the direction in which the orbiting satellite flies and preventing line disconnection during a call. ) Having a radio unit, a receiver, and a transmitter, the receiver is fixed to the first surface of the housing, and a helical antenna or a planar antenna is installed near the upper end of the second surface. A connector means (for example, a rotary connector) that is rotatable between the first coaxial cable and an electric motor (for example, a stepping motor) that rotates the antenna. To follow the circumferential direction of the satellite with the.
[0005]
1 to 3 show an embodiment of the present invention. 1 (a) is a perspective view of a mobile phone mounting a helical antenna for circularly polarized wave, and FIG. 1 (b) is a perspective view of a mobile phone mounting a planar antenna for circularly polarized wave, the same site the same reference numerals 1 is a mobile phone , 2 is a display unit, 3 is a receiver, 4 is an operation unit, a is a first surface (front) of the housing, b is a second surface (back) of the housing, and c is a housing. This is the third surface (upper surface). In FIG. 1 (a), 11 is a helical antenna, and in FIG. 1 (b), 21 is a planar antenna that emits radiation in a zenith direction by circular polarization.
[0006]
2A and 2B show examples of antenna radiation patterns. FIG. 2A shows a radiation pattern of a circularly polarized helical antenna, and FIG. 2B shows a radiation pattern of a circularly polarized flat antenna.
[0007]
FIG. 3 shows an apparatus configuration example for rotating the helical antenna 11 according to the present invention, wherein 12 is a first feeding point. First, the operation and characteristics of the helical antenna 11 that generates circularly polarized waves for satellite communication will be described, and then the effect of rotating the helical antenna 11 will be described. The helical antenna 11 is composed of a coaxial line 13 and a conductive wire 14 that serve both as a radiating element and a normal conductor line. The helical conductor 11 electrically couples the central conductor of the coaxial line 13 and the conductive wire 14 at the feeding point 12, and ends the winding of the conductive wire 14. At the end 15, the outer conductor 13 a of the coaxial line 13 is electrically coupled.
[0008]
First, the operation of the helical antenna will be described based on the high-frequency current flowing through the helical antenna 11. The feeding point 12 of the helical antenna 11 is located at the tip of the antenna, and the outer conductor 13a of the first coaxial line 13 is not connected to anything that becomes an antenna element. The high-frequency current flowing out from the feeding point 12 flows from the bottom end 15 toward the top from the bottom on the outer wall side of the outer conductor 13 a of the coaxial line 13. On the other hand, a reverse current flows on the inner wall side of the outer conductor 13 a of the coaxial line 13. Therefore, apparently no high frequency current flows through the outer conductor 13a of the coaxial line 13.
[0009]
By the way, the coaxial line 13 is filled with an internal dielectric 13b (polyethylene or the like) that separates the center conductor and the external conductor 13a. Further, high frequency energy is consumed by an external dielectric (not shown) that protects the external conductor 13a, the internal dielectric 13b, and the like, and the radiation pattern shown in FIG. 2 (a) is a coaxial line among the wires constituting the helical antenna 11. The direction in which 13 is dominant indicates that the radiation gain of the antenna is deteriorated by about 3 dB as compared with the direction in which the conductor 14 is dominant. Further, depending on the direction, the degradation is as much as 6 dB. This pattern uses a coaxial wire using a relative dielectric constant of 2.3 and a dielectric loss of 3 × 10 ⁻⁴ as the inner dielectric 13b of the coaxial wire 13, and using polyvinyl chloride as a coating for the outer conductor 13a. In this example, the length of the antenna is 23 cm, the diameter of the antenna is 4 cm, and the number of turns is 2 turns. FIG. 2A shows a radiation pattern centering on the axis of the helical antenna 11 with the helical antenna configured as described above standing vertically.
[0010]
Here, in order for the user of the cellular phone to communicate comfortably without being aware of the direction in which the satellite is flying, the antenna unit is rotated in a direction in which the radiation characteristic of the circularly polarized antenna is good. For this purpose, a rotary connector 31 with a gear is provided between the antenna unit and the radio circuit unit, and the antenna side is rotated by an electric prime mover (for example, a stepping motor) 32 or the like. In order to control the rotation angle of the antenna, the rotation of the electric prime mover 32 provided with the gear 32a is controlled by the rotation angle control means 42 so that the reception signal is maximized by the detection signal from the reception signal intensity detector 41. .
[0011]
Another embodiment of the present invention will be described with reference to FIG. In FIG. 1B, the planar antenna 21 includes a patch-like conductor 22, a plate-like dielectric substrate 23, a ground conductor plate 24, and feed pins 25. Since an example of a mechanism device for rotating the planar antenna 21 can be the same as that shown in FIG. 3, illustration and description thereof are omitted.
[0012]
The planar antenna 21 is configured by printing a patch-like conductor 22 serving as a radiating element on the upper surface of a dielectric substrate 23. At this time, the patch-like conductor 22 has a rectangular shape with slightly different vertical and horizontal lengths. The long side of the rectangle operates as a linearly polarized antenna at the frequency fL, and the short side operates as a linearly polarized antenna intersected at the frequency fH. The antenna operates as a circularly polarized antenna between the frequency fL and the frequency fH.
[0013]
By the way, when the radiation pattern is measured with the planar antenna at an elevation angle of 0 degree, a difference of about 5 dB occurs between the maximum and minimum sensitivity as shown in FIG. In order to compensate for this sensitivity deterioration, a rotation mechanism is provided in the same manner as the helical antenna, and the rotation angle is controlled.
[0014]
【The invention's effect】
As described above, according to the present invention, since the antenna rotating device directs the direction in which the circularly polarized antenna has good directivity characteristics to the direction in which the satellite flies, communication can be performed with good sensitivity. In addition, the transmission power from the mobile phone can be saved, and the call can be made longer.
[Brief description of the drawings]
FIG. 1A is a perspective view of a mobile phone to which a helical antenna is attached in an embodiment of the present invention, and FIG. 1B is a perspective view of a mobile phone to which a planar antenna is attached in another embodiment.
FIGS. 2A and 2B show a radiation pattern at an elevation angle of 0 degree, where FIG. 2A is a measurement example of a helical antenna, and FIG.
FIG. 3 is a diagram illustrating a rotating mechanism of a helical antenna.
FIG. 4 is a perspective view showing a conventional example.
[Explanation of symbols]
a: First surface (front) of the housing
b: Second surface (back surface) of the housing
c: Third surface (upper surface) of the housing
1: mobile phone 2: display unit 3: receiving unit 4: operating unit 5: transmitting unit 11: helical antenna 12: feeding point 13: coaxial line 13a: outer conductor 13b of coaxial line: inner dielectric 14 of coaxial line: Conductor 15: first coaxial line and winding end 16 of conductor: Dielectric cylinder 21: microstrip line planar antenna (planar antenna)
22: Patch-like conductor 23: Ground conductor plate 24: Dielectric substrate 25: Feed pin 26: Through hole 27 for the feed pin of the ground conductor plate: Coaxial line 31: Rotary connector 32 with gears: Electric motor (stepping motor) )
32a: gear 41: received signal strength detector 42: rotation angle control means 201: mobile phone 202: transmitting microstrip line planar antenna 203: receiving microstrip line planar antenna 204: folding antenna array

Claims (2)

Circularly polarized antenna for transmitting and receiving for satellite communication, rotating means for rotating the circularly polarized antenna around the antenna axis, driving means for transmitting power to the rotating means, and received signal of the circularly polarized antenna A cellular phone comprising: a casing including detection means for detecting intensity; and a rotation angle control means for controlling the driving means so that a detection result of the detection means is maximized. 2. The mobile phone according to claim 1, wherein the rotating means is constituted by a rotary connector, and the rotary connector is provided in the middle of a coaxial line constituting the antenna shaft for connecting the circularly polarized antenna and the radio circuit unit. Phone .

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