JPH04239235A - Antenna setting state inspecting device - Google Patents

Abstract

PURPOSE:To easily check the influence to the antenna at the installed position on the spot. CONSTITUTION:Signals are generated from a transmission frequency generation circuit 1 and a reception frequency generation circuit 2, and signals with the frequency of the transmission/reception bands are inputted to an antenna 5. The level of the reflection wave due to the antenna 5 of the signal is detected by a transmission signal level detection circuit 7 and a reception signal level detection circuit 8. When the level of the reflection wave from the antenna 5 is high, it is judged that the installed place of the antenna 5 is not good and the conformity of the antenna 5 can not be taken.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna installation state inspection device for inspecting the influence on an antenna at its installation location.

0002

2. Description of the Related Art Antennas are generally designed assuming an ideal space, adjusted, etc., and then used as is. However, in actual use, there are various structures around the antenna, and the space is rarely ideal, so antenna characteristics such as impedance characteristics deviate from desired values, making it impossible to perform good transmission and reception. There was a case. For example, placing an antenna inside a dielectric structure shifts the antenna's resonant frequency. When investigating on-site whether the amount of shift in the resonant frequency has an effect on the wireless system, conventional methods require a large number of measurement devices, making the task extremely troublesome.

0003

[Problems to be Solved by the Invention] The present invention has been made in view of the above points, and its purpose is to determine whether the influence on the antenna at the location where the antenna is installed is a problem. An object of the present invention is to provide an antenna installation state inspection device that allows easy inspection on site.

0004

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a transmitting frequency signal generating circuit that generates a transmitting frequency signal, a receiving frequency signal generating circuit that generates a receiving frequency signal, and a receiving frequency signal generating circuit that generates a receiving frequency signal. a first switch that selectively outputs the signals from both signal generation circuits; and a first switch that outputs the signal from the first switch to the antenna connected to the first output terminal, and a second switch that outputs the signal from the first switch to the antenna connected to the first output terminal; a circulator that outputs from the output terminal; a second switch that is switched in conjunction with the first switch and selectively outputs the reflected wave output from the second output terminal of the circulator from the two output terminals; A transmission signal level detection circuit that detects the level of the reflected wave of the transmitted signal and determines whether the level is below a predetermined level; and a transmission signal level detection circuit that detects the level of the reflected wave of the received signal and determines whether the level is below the predetermined level. It is equipped with a received signal level detection circuit that determines the level of the received signal.

[0005] Note that a similar antenna installation state inspection device can be constructed by using a mixer in place of the first switch and a duplexer in place of the second switch. In addition, there is a reference signal generation circuit that generates a reference signal, a high frequency signal generation circuit that generates signals of all frequencies in the transmission band and reception band based on the output of this reference signal generation circuit, and a signal from the high frequency signal generation circuit. a circulator that outputs a wave reflected from the antenna to an antenna connected to a first output terminal and outputs a reflected wave from the antenna from a second output terminal, and a local oscillation signal generation circuit that generates a local oscillation signal based on a reference signal generation circuit. and a mixer that mixes the reflected wave from the antenna output from this circulator with a local oscillation signal to convert it into an intermediate frequency. To provide an antenna installation state inspection device that can easily check on site whether the influence on the antenna becomes a problem at the place where the antenna is installed even if it is configured with a level detection circuit that determines whether or not the antenna is installed. I can do it.

[0006]

[Operation] By configuring the present invention as described above,
Input the frequency signals of the transmitting band and receiving band to the antenna,
Detect the level of the reflected wave of that signal by the antenna,
enable the matching state of the antenna to be determined;
This makes it possible to easily check on-site whether the influence on the antenna will be a problem at the location where the antenna is installed.

[0007]

[Embodiment] (Embodiment 1) FIG. 1 shows an embodiment of the invention. The antenna installation state inspection device of this embodiment includes a transmission frequency signal generation circuit 1 that generates a transmission frequency signal, a reception frequency signal generation circuit 2 that generates a reception frequency signal, and both signal generation circuits 1 and 2. a first switch 3 that selectively outputs a signal; and a first switch 3 that selectively outputs a signal of
While outputting to the antenna 5 connected to the output terminal of
A circulator 4 that outputs the reflected wave from the antenna 5 from a second output terminal, and a circulator 4 that is switched in conjunction with the first switch 3 to selectively output the reflected wave from the second output terminal of the circulator 4. a second switch 6 that outputs from two output terminals; a transmission signal level detection circuit 7 that detects the level of the reflected wave of the transmitted signal and determines whether the level is below a predetermined level; It consists of a received signal level detection circuit 8 that detects the level and determines whether the level is below a predetermined level, and displays 9 and 10 that display the determination results of both level detection circuits 7 and 8, respectively. . Note that the transmission frequency generation circuit 1 and the reception frequency generation circuit 2 are capable of generating signals of all frequencies in the transmission band and the reception band, respectively.

When a signal is being generated from the transmission frequency generation circuit 1, the first and second switches 3 and 6 connect the transmission frequency generation circuit 1 to the transmission signal level detection circuit via the circulator 4 and the antenna 5. 7. At this time, the level of the reflected wave from the antenna 5 is detected by the transmitted signal level detection circuit 7, and it is determined whether the reflected wave level is below a predetermined level. In other words, the lower the level of the reflected wave returning from the antenna 5, the better the antenna 5 is matched at that frequency. Display that there is little impact at the installation location. On the other hand, if the level is above a predetermined level, the display 9 indicates that the antenna 5 is affected and the installation location is unfavorable. Alternatively, if a signal is generated from the reception frequency generation circuit 2, and the level of the reflected wave is determined by the reception signal level detection circuit 8 via the first switch 3, circulator 4, antenna 5, and second switch 6. Regarding the receiving band, it is possible to judge whether the installation location of the antenna 5 is good or bad in the same way. Therefore, according to this embodiment, it is possible to easily determine whether the installation location of the antenna 5 is good or bad at the site.

(Embodiment 2) FIG. 2 shows another embodiment of the present invention. In this embodiment, a mixer 11 is used in place of the first switch 3 of the first embodiment, and a second A duplexer 12 is used in place of the switch 6. In this embodiment, signals are simultaneously generated from the transmission frequency signal generation circuit 1 and the reception frequency signal generation circuit 2, and these signals are mixed by the mixer 11 and output to the antenna 5 via the circulator 4. Then, a branching filter 12 separates the components of the reflected wave from the antenna 5 into each transmission band and reception band, and separates the components into a transmission signal level detection circuit 7 and a reception signal level detection circuit 8.
The signal level detection circuits 7 and 8 determine whether the level of the reflected wave is below a predetermined level, as in the first embodiment.

(Embodiment 3) FIG. 3 shows still another embodiment of the present invention. In this embodiment, the high-frequency signal generating circuit 14 generates frequency signals for the transmitting band and receiving band based on the output of the reference signal generating circuit 13, whereas signals of the transmitting band and receiving band frequencies were generated separately in each of the above-mentioned embodiments. It generates signals of all frequencies. Then, a local oscillation signal generated by the local oscillation signal generation circuit 15 based on the reference signal generation circuit 13 is added to the signal that is output from the high frequency signal generation circuit 14 through the circulator 4 to the antenna 5 and reflected from the antenna 5. The signals are mixed and converted into an intermediate frequency, and from the signal reduced to this intermediate frequency, a signal level detection circuit 17 determines whether the level of the reflected wave is below a predetermined level, and displays the result on the display 8. In the case of this embodiment as well, it is possible to easily check the quality of the installation location of the antenna 5 on site in the same manner as in the above-mentioned embodiments.

[0011]

Effects of the Invention As described above, the present invention includes a transmission frequency signal generation circuit that generates a transmission frequency signal, a reception frequency signal generation circuit that generates a reception frequency signal, and a signal generation circuit that generates a signal from both of the above signal generation circuits. a first switch that selectively outputs; a circulator that outputs a signal from the first switch to an antenna connected to a first output terminal and outputs a reflected wave from the antenna from a second output terminal;
a second switch that is switched in conjunction with the first switch and selectively outputs the reflected wave output from the second output terminal of the circulator from the two output terminals; a transmission signal level detection circuit that detects and determines whether the level is below a predetermined level;
It is equipped with a received signal level detection circuit that detects the level of the reflected wave of the received signal and determines whether the level is below a predetermined level. It is possible to determine the matching state of the antenna by detecting the level of the reflected wave of the signal by the antenna. Therefore, this antenna installation state inspection device alone can detect the antenna at the location where the antenna is installed, without using many other devices. It is possible to easily check on-site whether the impact is a problem.

[0012] Furthermore, a similar antenna installation state inspection device can be constructed by using a mixer in place of the first switch and a duplexer in place of the second switch. Furthermore, a reference signal generation circuit that generates a reference signal, a high frequency signal generation circuit that generates signals of all frequencies in the transmission band and reception band based on the output of this reference signal generation circuit, and signals from the high frequency signal generation circuit. a circulator that outputs a wave reflected from the antenna to an antenna connected to a first output terminal and outputs a reflected wave from the antenna from a second output terminal, and a local oscillation signal generation circuit that generates a local oscillation signal based on a reference signal generation circuit. and a mixer that mixes the reflected wave from the antenna output from this circulator with a local oscillation signal to convert it into an intermediate frequency. To provide an antenna installation state inspection device that can easily check on site whether the influence on the antenna becomes a problem at the place where the antenna is installed even if it is configured with a level detection circuit that determines whether or not the antenna is installed. I can do it.

[Brief explanation of the drawing]

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

FIG. 2 is a configuration diagram of another embodiment.

FIG. 3 is a configuration diagram of still another embodiment.

[Explanation of symbols]

1 Transmission frequency signal generation circuit 2 Reception frequency signal generation circuit 3 First switch 4 Circulator 5 Antenna 6 Second switch 7 Transmission signal level detection circuit 8 Received signal level detection circuit 11, 16 Mixer 12 Duplexer 13 Reference signal generation circuit 14 High frequency signal generation circuit 15 Local oscillation signal generation circuit 17 Level detection circuit

Claims (3)

[Claims] 1. A transmission frequency signal generation circuit that generates a transmission frequency signal, a reception frequency signal generation circuit that generates a reception frequency signal, and a first circuit that selectively outputs signals from both of the signal generation circuits. a switch, a circulator that outputs a signal from the first switch to an antenna connected to a first output terminal and outputs a reflected wave from the antenna from a second output terminal; and a circulator that operates in conjunction with the first switch. a second switch that selectively outputs the reflected wave output from the second output terminal of the circulator from the two output terminals; and a second switch that detects the level of the reflected wave of the transmitted signal and adjusts the level to a predetermined level. and a received signal level detection circuit that detects the level of the reflected wave of the received signal and determines whether the level is below a predetermined level. Antenna installation condition inspection device. 2. An antenna installation state inspection device according to claim 1, wherein a mixer is used in place of the first switch, and a duplexer is used in place of the second switch. 3. A reference signal generation circuit that generates a reference signal, a high frequency signal generation circuit that generates signals of all frequencies in a transmission band and a reception band based on the output of the reference signal generation circuit, and a high frequency signal generation circuit. a circulator that outputs a signal from the antenna to an antenna connected to a first output terminal and outputs a reflected wave from the antenna from a second output terminal; and a local oscillator that generates a local oscillation signal based on a reference signal generation circuit. A signal generation circuit, a mixer that mixes the reflected wave from the antenna output from the circulator with a local oscillation signal and converts it to an intermediate frequency, and a signal that is reduced to the intermediate frequency by the mixer and then has a predetermined level of the reflected wave. An antenna installation state inspection device comprising: a level detection circuit for determining whether the level is below the level.