JPS6269733A - Antenna system - Google Patents

Abstract

PURPOSE:To obtain an excellent reception state in a short time by swinging the beam direction of the synthesization orientation characteristic of the entire antenna by horizontally expanding an amplitude angle slowly when the reception state deteriorates. CONSTITUTION:When a receiver 42 selects a target program and detects an excellent reception state, monitoring continues. If said state is defective, the beam direction of the synthesized directivity is rotated to right by 45 deg. from an initial position 0 deg., and detects and decides the reception state. When the reception state is satisfactory, the pattern number is updated to keep monitoring the reception state. If the operation state again becomes defective, the beam of an active antenna is rotated to lelt by 45 deg. from 0 deg. in the reverse way of the former defective reception state. Then the reception state is detected and decided. When the reception state is excellent, the pattern number is updated to keep monitoring. If it is defective, such judgement is made that the incoming direction of a wave does not exist in a range of 45 deg. at both right and left sides, and an amplitude value is updated. The same action is repeated, and the beam direction of the synthesized directivity is horizontally amplified one by one, whereby the beam direction with the excellent reception state is detected.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to a receiving device, in particular, to controlling the combined directivity characteristics of the entire antenna obtained by combining the outputs of a plurality of antennas installed on a moving object. A good receipt! The present invention relates to a receiving device that maintains a fortune telling.

[Traditional background]

In general, an antenna for a mobile object, for example, a dual-use antenna, is constructed by providing a whip antenna l in a portion of a middle wall C, as shown in FIG. As shown in FIG. 9, the directional characteristics of such a whip antenna l are relatively fixed, so it is designed so that the receiving sensitivity does not change much no matter which direction the middle wall C faces.

However, using the whip antenna l,
When trying to receive FM broadcasts in the 90MHz frequency band while driving in a city, as shown in Figure 10,
Multipath reception may occur in which direct waves of broadcast radio waves and reflected waves reflected by buildings, etc. are received simultaneously. In such a case, the omnidirectional whip antenna 1 receives the direct wave and the indirect wave at almost the same level, and the received electric field level decreases and eventually echo distortion occurs, impeding good reception. . Furthermore, when traveling in a region with a weak electric field, the electric field changes constantly due to the movement of heavy vehicles, and signals may be received with so-called skip noise called "Zara, Zara."

An effective means for preventing such skip noise and the like is an antenna device (active antenna) that controls the directivity characteristics of the antenna by phase-combining a plurality of antennas.

[Conventional technology]

As such an active antenna, there is a conventional one such as the one shown in FIG.
No. 22).

Figure 10 shows active antennas used in televisions, 2 and 3 are antennas with approximately the same characteristics, and 4 is an antenna with approximately the same characteristics.
is the receiver that adjusts the output of antenna 2 (+71 signal A adjustment,
5 is a receiver that combines the outputs of antennas 2 and 3.
This is a synthesizer that inputs to 6. 7 received! This is a reception state detection circuit that detects the reception state of JPT, 6, and specifically, a synchronization signal detection circuit that extracts the east direct synchronization signal "-+52 and the water mo synchronization signal S" from the video signal S1 output by the reception+it6. circuit 8, and a sampling signal generating circuit 9 which outputs a sampling signal S4 for sampling the ghost component of the color signal of the video signal S1 from these two synchronizing signals S2 and S3.
a sampling circuit 10 that samples the ghost component S5 of the color burst signal from the SI that transmits the video using The ghost burst amplification and detection circuit 11 amplifies and detects this ghost component S5 and outputs a detected voltage S6. 12 is the input point for the detection voltage Sb;
This is a directional characteristic control device that changes the directional characteristic of the antenna by controlling the received signal/adjuster 4 so that the detected voltage S6 is minimized.

Specifically, this directional characteristic control device 12 operates as follows (that is, the ghost burst amplification and detection circuit 11
When the detected voltage S6 is input from
” to adjust the phase level adjustment amount of the received signal adjuster 4 from 0° to 36°.
The minimum value of the detection voltage S is memorized by changing it within a range of 0 degrees. Next, in the second period [1, the received signal 3J rectifier 4 is phase-shifted again, and the ghost burst amplification/detection circuit 11 outputs the signal. When the detected voltage S6 becomes equal to the minimum value stored on the first cycle day, the phase shift operation of the received signal adjuster 4 is stopped +h. In this way, directivity control device? By controlling the directivity characteristics of the combined antennas 112, the receiver 6 can achieve a good reception condition.

[Problem that the invention seeks to solve]

By the way, such conventional receiving devices combine the outputs of multiple antennas with uniform characteristics, and also assume that the receiving station is a fixed receiving station such as a home television. This was done as a.

However, in the case of an antenna that is installed on a heavy object such as an antenna for IJtlJ4, even if an antenna with the same characteristics can be obtained, the characteristics will be different in the mounting situation due to the influence of the heavy, fully bent body, etc. For example, even if a whip antenna that is omnidirectional in free space is installed in a city, each antenna will have directivity. Moreover, at mobile receiving stations in cities, the reception conditions change frequently as the mobile object moves, so synthetic directivity control is used to improve reception conditions in a short time using antennas with uneven characteristics. This is extremely difficult to do with conventional receivers.

Therefore, one object of the present invention is to detect a good condition between short poems when the reception condition at a mobile receiving station deteriorates.

[P step for solving problems]

In order to solve the problem and achieve the object, the first stage of control of the composite directional characteristics of the antenna device of the present invention is as follows:
A storage means that stores the combination ratio of the phase and level of each antenna output for calculating the composite directional characteristics of the plurality of selected patterns; By driving the phase level adjuster with the beam direction of the composite directional characteristic centered on the beam direction of the composite directional characteristic at the time of detection of poor reception until a good reception condition is obtained, the beam direction of the composite directional characteristic is gradually widened to the left and right, while gradually increasing the amplitude angle. A directional characteristic control f stage is provided to form a composite directional characteristic of a specific pattern.

[Effect]

In the antenna device according to the present invention, when the reception condition becomes poor due to the composite directional characteristic directed in a certain specific direction, the control u4 means is configured to control the beam direction at the time of poor reception based on pre-programmed information. The beam direction of the composite directional characteristic is swung to the left and right, with the amplitude angle gradually increasing.
When the reception condition becomes good, the change in the beam direction of the composite directional characteristic is stopped in that direction, and the reception is
Continue n.

〔Example〕

Hereinafter, the present invention will be described in detail based on the accompanying drawings.

FIG. 1 shows an antenna device according to an embodiment of the present invention. In this figure, numerals 21 to 24 are antennas provided on moving bodies such as +ij and the like, and their outputs are input to phase level adjusters 31 to 34. The phase level adjusters 31-34 adjust the phase and output level of the output of each antenna 21-24. Then, the signals outputted from the phase level adjusters 31 to 34 are combined by a combiner 41 and input to a receiver 42 . At this time, the combined directivity characteristics of the entire antenna combined by the combiner 41 are determined by the combination ratio of the phases and output levels of the received waves in the phase bell adjustment performances 31 to 34. 60 is a storage device. As shown in FIG. 2, the adjustment jt of each antenna output necessary to direct the beam direction of the composite directional characteristic in an arbitrary direction is stored.

In other words, the table shown in FIG. 2 shows the composite directional characteristics when combining the four antennas 21 to 24 in a specific direction (for example, 11j1114 with the forward direction being 00) and the i coordinate. (thinking in terms of system),
The adjustment of the phase and level of each antenna output necessary to rotate the beam direction by 3600 degrees, 't, is summarized for each beam direction (for example, every 45 degrees). Numerical values necessary for controlling such composite directional characteristics are determined in advance through actual measurements, analysis, and the like.

Reference numeral 61 inputs the output signal from the reception state detector 43, reads information necessary to control the composite directional characteristic from the storage device 2t60, and adjusts the phase level adjusters 31 to 61 based on the programmed program. This is a directional characteristic control device that drives the antenna 34 to change the beam direction of the combined directional characteristic of the entire antenna to the left and right. Note that 44 is a speaker. Next, the operation of this antenna device will be explained. Figure 4 shows
7 is a flowchart showing a method for controlling a composite directional characteristic by the directional characteristic control device 61. FIG.

First, the memory used in FIG. 4 will be explained. N is a register that stores pattern numbers 1 to 8 of the composite directional characteristics in FIG. The register N! is a register that stores the pattern number t being searched. The amplitude values of the I; memory are values from 1 to 4, and are 45°, 90", and 135, respectively.
' , 180'' (7) Corresponds to the amplitude angle. RTH
NMAX is a constant that calculates the maximum value of the pattern number J, and is 8. 5ET
(N) is a subroutine in FIG. SET
(Nl) is the subroutine SET (
N) This is a subroutine for register N1
The control data corresponding to the pattern scent written in tα is read out from the storage device 60 and applied to the phase level adjuster 1. Decide. N! ←N+NS is the subroutine shown in Figure 8,
Nl←N-N5 is a subroutine shown in FIG.

In the configuration shown in FIG. 1, first, after turning on the power switch of the receiver 42, the frequency dial of the receiver 42 is adjusted to select a desired program. Then, the directional characteristic HI n 2? 6
The program stored in 1 starts, initializes registers N and NS (N←1, NS←1), reads control data corresponding to pattern number l from the storage device 60, and controls the phase level adjusters 31 to 1. 34, the beam direction of the composite directional characteristic is set to the initial position (0°) (SET (N)).

Next, the receiving state is detected (R←receiving state) and the receiving state is monitored (R≧RTH). If the receiving state is good, monitoring is continued.

However, if it is defective, the beam direction of the composite directional characteristic is rotated 45 degrees to the right from the initial position (Oo) (N+ ←N+N
S, SET (N+)), detects the reception status (R
←Reception status), determine the reception status (R≧RTH), if the receipt IE is good, update the pattern number N (N=N+), continue monitoring the reception status (R←Reception status, R≧RTH).

However, if the reception condition is poor again, the beam of the active antenna is rotated 45 degrees to the left from the initial position (0 degrees) (N+ ←N-N5, SET (N
+)), detects the reception status (R←Receipt!L;),
Reception (, 1 state is determined (R≧RTH). If the reception state is good, update the pattern number -J-N as described above (N=N+), and continue monitoring the reception state ( R←
reception status, R≧RTH).

Receipt letter this time too! If the wave is defective, it is determined that there is no direct wave arrival direction within 45° left and right, so the amplitude value NS is updated (NS←NS+1). The subsequent operations are the same as described above. By repeating this process, the beam direction of the composite directional pattern is gradually made wider in the left and right directions, the beam direction where the reception condition is good is detected, the beam direction of the composite directional pattern is fixed in this direction, and the reception is started. Continue monitoring the condition.

Therefore, by appropriately adjusting the sound volume of the receiver 42, it is possible to listen to music and voices without reception interference.

Therefore, according to this antenna device, when a single antenna moves to an urban area or a mountainous area and the reception condition deteriorates, the directional characteristic control device 61 immediately detects this change and restores good reception again using the same method as described above. It can be in 44 states. still,
Since the specifications of the antenna and the shape of the vehicle body differ depending on the model, the phase and level adjustment amounts that should be stored in the storage device 60 are summarized in the form of a table for each vehicle model, and can be replaced depending on the model in which the receiving device is installed. Ru. Further, since the phase and level adjustment g441 of each antenna differs depending on the frequency, it goes without saying that a table for each frequency is required. Further, in the table shown in FIG. 2, if the angular steps of the beam direction of the directional characteristics are made finer, more precise control of the directional characteristics can be realized.

Furthermore, in this example, we have described a direction in which the beam direction of the composite directional characteristic is gradually widened to the left and right by canceling the previous direction where the reception condition became good, but if the reception condition becomes poor due to random numbers. Alternatively, the beam direction may be changed randomly around the direction when the beam changes.

In the above explanation, we have explained radio broadcast reception, but there are also other ways to receive TV broadcast, personal radio, MCA, automatic 1
1 (Applicable to mobile communications such as telephones.

〔Effect of the invention〕

As explained above, the antenna device of the present invention has a heel L of the composite directional characteristic of the entire antenna when the reception condition becomes poor.
・It swings from side to side while gradually widening the amplitude angle. The change in the direction of arrival of the direct wave is due to the direction change due to the turning of both +lj, but in normal cases, the direction change angle of both +lj and 11t is within 90 degrees left and right, so it is In most cases, by swinging a beam with a composite directional characteristic to the left and right, a good reception condition can be obtained in a short time.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an antenna device according to the present invention,
Fig. 2 is a table showing the relationship between the phase and output level adjusters in each phase level adjuster and the beam direction of the directional characteristic, and Fig. 3 is an explanatory diagram of the pattern of the direction of the directional characteristic of the synthesized antenna >5. 4 to 7 are flowcharts showing the operation of the antenna device according to the present invention, FIG. 8 is a perspective view showing the whip antenna, FIG. 9 is an explanatory diagram showing the directional characteristics of the whip antenna, and FIG. An explanatory diagram showing direct waves and indirect waves received by a vehicle inside the vehicle, and FIG. 11 is a diagram showing a conventional antenna device. 21.22, 23.24... antenna 31, '32,
33.34...Phase level adjuster 41...Synthesizer 42...Receiver 43...Reception state detector 60...Storage device 61...Direction state detector No. 211 FIG. 9 Tadashi 1st
Figure 0 and Figure 11

Claims (1)

[Claims] A phase level adjuster adjusts the phase and level of the received waves received by each antenna of multiple antennas installed on a mobile object, and the output of each antenna adjusted by this phase level adjuster is combined to adjust the overall antenna. In an antenna device having a combiner for forming a composite directional characteristic, the storage means stores a combination ratio of the phase and level of each antenna output to obtain a composite directional characteristic of a plurality of preselected patterns, and the storage means stores the combination ratio of the phase and level of each antenna output in order to obtain a composite directional characteristic of a plurality of patterns selected in advance, Based on the memory value stored in the means, the phase level adjuster gradually changes the beam direction of the composite directional characteristic from left to right alternately until a good reception condition is obtained, centering on the beam direction of the composite directional characteristic at the time of detection of poor reception. 1. An antenna device comprising: directivity control means for forming a specific pattern of composite directivity by driving while widening the amplitude angle.