JP2002151902A - Device for uninterruptible switching of radio wave outputted from transmitter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an uninterruptible switching device in a small size, which avoids antenna power from being decreased at switching. SOLUTION: The switching device is provided with directional couplers 1 and 2 which respectively have main line input terminals 1A and 2A to which transmitters 11 and 12 are connected, main line input terminals 1B and 2B, sub line coupling terminals 1C and 2C and non-coupling terminals 1D and 2D, one of which is connected with an antenna 13 and the other a dummy load 14, with a T-branch line 5 that is provided in the middle of a main line interconnecting the main line output terminals 1B, 2B and a line 6 that is provided in the middle of a sub line interconnecting the sub-line coupling terminals 1C, 2C, with T-branch stubs 7 and 8 to change the reactance in the T-branch lines 5 and 6 and with a simultaneous drive means 9 that moves the T-branch stubs 7, 8 to change the reactance while keeping each of the reactance the same. By changing the impedance of the T-branch line 5 and 6 under the control of the simultaneous drive means 9 at switching, a state of signal passing and full reflection of the signal can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for connecting one antenna to the output of one of first and second transmitters.
The present invention relates to a transmitter output uninterruptible switching device that switches and connects to the other output without an instantaneous interruption, and more particularly to an uninterruptible transmitter output uninterruptible that can avoid a decrease in antenna power at the time of switching and can achieve downsizing of the device. The present invention relates to a switching device.

[0002]

2. Description of the Related Art In a television broadcast or the like, a spare transmitter is always provided in order to avoid a short stop of radio waves (hereinafter simply referred to as a stop). Further, in switching of high power as in a broadcasting machine, damage to the contacts occurs, so that the high power cannot be cut off at the contacts. In addition, since the load impedance of the transmitter is disturbed, a reflected signal is generated to adversely affect the transmitter, and an accident due to high-frequency discharge or the like may occur. For this reason, in the past, switching was performed after the transmitter output was stopped. Therefore, the switching operation of the transmitter cannot be performed during the broadcast. However, service interruptions are not allowed even for a short time. Therefore, there are several proposals for a transmitter output uninterrupted switching device.

[0003] For example, as this type of uninterrupted switching device for transmitter output, there is a high-frequency combining switching device disclosed in Japanese Patent Application Laid-Open No. 1-280901. This high-frequency synthesis switching device is provided with two high-frequency switch groups in order to avoid an instantaneous interruption of a signal at the time of synthesis switching and to realize miniaturization.

[0004] One high-frequency switch group 10 includes, for example,
As shown in FIG. 7, four terminals a, b, c, and d at the positions of the vertices of the square, and these terminals a, c, c, b, b, d, and d, a And four contact pieces 15 for short-circuiting. Transmitters 11 and 12 are connected to the input terminals a and b, respectively.
An antenna 13 is connected to the output terminal c, and a pseudo load 14 is connected to the output terminal d as a pseudo antenna.

Next, the power level supplied to the antenna when the high-frequency switch group 10 performs the switching operation will be described with reference to FIG. 7 and FIG.

FIG. 8 shows an example of the power level supplied to the antenna 13 over time when the high-frequency switch group 10 of FIG. 7 performs the switching operation.

First, at time t0 in the state of FIG.
The two opposing contact pieces 15 are terminals a and c and terminals b and d.
Since each is short-circuited, the output of the transmitter 11 is supplied to the antenna 13 and the output of the transmitter 12 is supplied to the dummy load 14. Therefore, 100% of the output of the first transmitter 11 is supplied to the antenna 13. At this time, the output of the second transmitter 12 is supplied to the dummy load 14.

Next, at time t1 when switching of the transmitter 11 to the transmitter 12 is started, the two contact pieces 15 start operating to short-circuit the terminals c and b and terminals d and a, respectively. The state is as shown in FIG. However, in a short time, the remaining two contact pieces 15 start operating to release the short-circuit between the terminals a and c and the terminals b and d, so that at the time t3, the opening as shown in FIG. State. As a result, the antenna 13 is supplied with 100% of the output of the second transmitter 12, and the output of the first transmitter 11 is supplied to the dummy load 14.

[0009] However, as shown in FIG. 8, in the course of the switching, although a short time of 100 msec, a simultaneous connection state such as the time t 2 occurs, and a reflected signal of about −6 dB is transmitted to the transmitters 11 and 12. Returning, a transmission loss of about −6 dB occurs in each of the antenna 13 and the pseudo load 14. In this case, the antenna 13 is supplied with power from the transmitters 11 and 12 at a level of 25%, that is, 50% in total.

For example, there is a transmitter output coaxial switching device disclosed in Japanese Utility Model Laid-Open No. 57-104668.

In this coaxial switching device, for example, as shown in FIG. 9, directional couplers 1 and 2 having a coupling degree of 3 dB are used. Each of the directional couplers 1 and 2 has a main line input terminal 1
A, 2A, main line output terminals 1B, 2B, sub line coupling terminals 1C, 2C, and sub line non-coupling terminals 1D, 2D.

The transmitters 11 and 12 are connected to the main line input terminals 1A and 2A of the directional couplers 1 and 2, respectively. The antenna 13 and the dummy load 14 are connected to the sub-line uncoupled terminals 1D and 2D, respectively. The main line output terminals 1B and 2B and the sub line coupling terminals 1C and 2C are connected by the main line 3 and the sub line 4, respectively. Capacitively-coupled coaxial switches 50 and 60 are provided between the main line 3 and the sub-line 4, respectively. Some of the capacitively coupled coaxial switches 50 and 60 are disclosed, for example, in Japanese Utility Model Laid-Open No. 52-50034.

That is, the capacitively coupled coaxial switches 50 and 6
When the capacitances of the zero capacitors 70 and 80 are simultaneously changed, the outputs of the transmitters 11 and 12 are continuously switched to the antenna output with the function of signal passing and reflection accompanying the phase change of the reflected wave. Can be.

[0014]

The above-described conventional transmitter output uninterruptible switching device has the following problems.

The first problem is disclosed in Japanese Patent Application Laid-Open No. 1-280901.
The high frequency synthesizing switching device disclosed in Japanese Patent Laid-Open Publication No. 2002-157,026 is unsuitable for the future digital broadcasting era.

The reason is that when switching the transmitter,
Although it is a short time of 0 msec, a transmission loss of about -6 dB is generated due to the reflected wave, and the supplied power is reduced to 50%. This is because terrestrial digital broadcast waves are not allowed. That is, if the output level of the antenna cannot be kept constant in the digital terrestrial broadcast wave, the broadcast reception range is extremely reduced.

The first problem is that of Japanese Utility Model Laid-Open No. 57-1046.
The problem can be solved by the coaxial switching device of the transmitter output disclosed in Japanese Patent No. 68.

However, in this coaxial switching device, as a second problem, it has occurred that an increase in the scale is inevitable.

The reason is that the capacitively-coupled coaxial switch provided between the main line and the sub-line of the coaxial switching device requires a large area and thickness for the capacitor for switching large-capacity power. Because it becomes.

SUMMARY OF THE INVENTION An object of the present invention is to solve such a problem and, when switching the transmitter output, avoid an instantaneous interruption of the output as well as a reduction in the antenna power and achieve an uninterrupted transmitter output that can be downsized. A wave switching device is provided.

[0021]

SUMMARY OF THE INVENTION According to the present invention, there is provided an uninterruptible switching device for a transmitter output, wherein one antenna is connected to the output of one of a first and a second transmitter while the other is continuously connected to the other. The main line input terminal for connecting one transmitter, the main line output terminal for connecting the main line, the sub line coupling terminal for connecting the sub line, and the antenna on one side and the other on the other side Two directional couplers each having a non-coupled terminal for connecting a pseudo load, a main line connecting the main line output terminals of the two directional couplers, and the sub-line connecting the sub-line coupled terminals The two T-type branch lines provided at each of the intermediate positions of the two, the two variable reactance elements that change the reactance in each of the two T-type branch lines, and the two variable reactance elements are held at the same value. And a single simultaneous driving means for changing the Riakutansuchi.

With this configuration, the output signal from the transmitter is passed and totally reflected by changing the reactance value in each of the T-type branch lines provided on the main line or the sub line connecting the two directional couplers. And the antenna can be continuously supplied with 100% of the power at the transmitter. Further, since the T-shaped branch line is formed on the main line and the sub line connecting the two directional couplers, the size of the device can be relatively reduced with respect to the size of the output.

The variable reactance element may have at least one T-branch stub structure formed on the main line and the sub-line, or a plurality of T-branches having a quarter wavelength interval on the main line and the sub-line. It is desirable to configure with a branch stub. Further, the variable reactance element includes:
Forming at least one mechanically contacting plunger structure on the T-branch line, with a slight gap between the inner conductor and the outer conductor so as not to contact the inner conductor wall of the T-branch line; The choke may have a choke structure in which the chokes are arranged at a distance, and the choke may have at least one quarter wavelength.

Further, when the two transmitters switch outputs, the two transmitters have the same amplitude and phase, so that 100% power can be continuously supplied to the antenna.

[0025]

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

FIG. 1 is a functional block diagram showing an embodiment of the present invention. In the uninterruptible switching device of the transmitter output shown in FIG. 1, directional couplers 1 and 2 having a coupling degree of 3 dB are used. The directional couplers 1 and 2 respectively include main line input terminals 1A and 2A, main line output terminals 1B and 2B, sub line coupling terminals 1C and 2C, and sub line non-coupling terminals 1D and 2D.
Is provided similarly to the conventional device.

That is, the transmitter 11 is connected to the main line input terminal 1 A of the directional coupler 1. On the other hand, the transmitter 12 is connected to the main line input terminal 2A of the directional coupler 2. The antenna 13 is connected to the sub-line non-coupling terminal 2D of the directional coupler 2. The pseudo load 14 which is a pseudo antenna is connected to the sub-line non-coupling terminal 1 of the directional coupler 1.
D. The main line output terminals 1B and 2B and the sub line coupling terminals 1C and 2C are connected to the main line 3 respectively.
And the sub-line 4.

The present invention differs from the conventional one in that the main line 3
And T-branch lines 5 and 6 are provided at intermediate positions of the sub-lines 4 in place of the capacitive coupling switches.
In FIG. 1, T-branch stubs 7 and 8 are provided as variable reactance elements in the T-branch lines 5 and 6, respectively.
Each of the T-branch stubs 7, 8 forms a plunger structure incorporated in the T-branch lines 5, 6, and the simultaneous driving means 9
Is instructed to move the position. Therefore, the reactance value of each of the T-shaped branch lines 5 and 6 changes according to the instruction of the simultaneous driving means 9.

Each of the T-branch stubs 7 and 8 shown in FIG. 1 constitutes a set of two elements with an interval of a quarter wavelength, but each of the T-branch stubs 7 and 8 has the same number of elements. If there is, there is no limit on the number.

The simultaneous driving means 9 automatically controls the T-type branch lines 5 and 6 so as to have the same reactance value, and simultaneously changes the reactance value when switching the transmitter output.

The amplitudes and phases of the outputs of the transmitters 11 and 12 are adjusted to the same value as in the conventional case. Therefore, as will be described later with reference to FIG. 6, when the transmitter output is switched by changing the reactance value, the antenna 1
3, 100% output power appears continuously.

FIG. 2 shows an embodiment of a variable reactance element different from that of FIG.

FIG. 2A shows a T-type branch line 5A (6) provided on the main line 3 (4) as a variable reactance element.
Movable shorting piece 7A (8A) with mechanical contact at A)
It is shown. FIG. 2B shows the main line 3 (4).
In the T-shaped branch line 5B (6B) provided in the first embodiment, a movable portion forms a choke structure at a small distance without mechanically contacting a metal wall surface, and a choke 7B (8B) having a quarter wavelength is shown. Have been.

Next, a 3 dB directional coupler will be described with reference to FIG.

As described above, the directional coupler has the main line input terminal A, the main line output terminal B, the sub line coupling terminal C, and the sub line non-coupling terminal D. The high frequency input power input from the main line input terminal A is output from the main line output terminal B and the sub line coupling terminal C by 50% of the input power, respectively, and is not output to the sub line non-coupling terminal D. On the other hand,
The power input from each of the main line output terminal B and the sub line coupling terminal C is output as a sum from the sub line non-coupling terminal D and not output to the main line input terminal A.

Next, referring to FIGS. 4 to 8 together,
The switching operation according to the present invention will be described.

FIG. 4 differs from FIG. 1 in that a two-element T-branch stub 7 (8) is replaced by a one-element T-branch stub 71 (81).
And the line length from the branch point of the main line 3 (sub-line 4) to the short-circuit point by the T-branch stub 71 (81) is set to a quarter wavelength of the transmission output frequency at the output of the transmitter 11 (12). It is that.

In this state, both the main line 3 connecting the main line output terminals 1B and 2B of the directional couplers 1 and 2 and the sub line 4 connecting the sub line coupling terminals 1C and 2C are both signals. It is in a passing state. Therefore, due to the characteristics of the directional coupler described above, the output power of the first transmitter 11 changes its phase, but almost 100% of the output power is supplied to the antenna 13 via the main line 3 and the sub line 4, respectively. You. The output power of the second transmitter 12 depends on the main line 3 and the sub line 4
It is supplied to the dummy load 14 via each.

That is, the state at the time t0 shown in FIG. 6 is formed.

Next, referring to FIG. 5, the difference from FIG. 4 is that the T branch stub 7
2 (82) to the transmitter 11 (1
2) half the wavelength of the transmission output frequency at the output,
That is, the line length changes from one quarter to one half of the wavelength.

In this state, both the main line 3 connecting the main line output terminals 1B and 2B of the directional couplers 1 and 2 and the sub line 4 connecting the sub line coupling terminals 1C and 2C are both at the midpoint. A short-circuit state of the load is formed in each of the T-type branch lines 5 and 6. Therefore, almost 100% of the output power of the first transmitter 11 is the main line 3 and the sub line 4
Each is totally reflected and supplied to the dummy load 14 by the characteristics of the directional coupler described above. On the other hand, the second transmitter 1
Almost 100% of the output power of No. 2 is totally reflected by the main line 3 and the sub line 4, respectively, and supplied to the antenna 13.

That is, a state after time t3 shown in FIG. 6 is formed.

Time t1 shown in FIG. 6 is the time when the transition from the state in FIG. 4 to the state in FIG. 5 is started in the process of moving the short-circuit point by the T-branch stub. Therefore,
Until time t3, the line length from the above-described branch point to the short-circuit point gradually changes from ４ to ２.

Time t2 is the time when the line length reaches 153.4 degrees in terms of the electrical length of the transmission output frequency of the transmitters 11 and 12. At this point, the load impedance of the T-type branch lines 5 and 6 with respect to the signals received from the transmitters 11 and 12 becomes twice the route. Therefore, T
Both the passing power and the reflected power in the respective branch lines 5 and 6 are in a state of minus 3 dB, and the transmitters 11 and 1
50% of each output power is supplied to the antenna 13 and the dummy load 14, respectively.

As described above, from time t1 to time t2
Through time t3, the load impedance of the T-type branch lines 5 and 6 with respect to the signals received from the transmitters 11 and 12 gradually changes from the signal passing state to the total reflection state, and the T-type branch line 5 , 6 can be made equal by the simultaneous driving means (see FIG. 1). Therefore, the sum of the powers appearing at the sub-line uncoupled terminals 1D and 2D from both the transmitters 11 and 12 is always constant. That is, power equivalent to 100% output power of one transmitter appears in the antenna 13.

In the above description, the variable reactance element has been illustrated and described using a short-shaped stub. However, the reactance can be changed at the intermediate portion between the main line and the sub line such as another open stub or a filter circuit. The present invention is not limited to the above embodiment as long as it is one.

[0047]

As described above, according to the present invention, there is provided an uninterruptible switching device for a transmitter output in which a variable reactance element is provided at an intermediate portion between each of a main line and a sub line connecting two directional couplers. I got it.

As a result, it is possible to switch to the output signal of the transmitter during standby without stopping the output signal to the antenna of the transmitter during broadcasting and keeping the output to the antenna constant. The effect is that the transmitter can switch between the working transmitter and the backup transmitter without causing both the instantaneous interruption of the broadcast wave at the time of switching in the digital broadcast wave and the reduction of the service area due to the decrease in the received electric field strength. can get.

Further, the variable reactance element controls transmission and reflection of a signal by a T-shaped branch line provided at an intermediate portion between the main line and the sub line, so that the size can be reduced as compared with the capacitive coupling type. Is also obtained.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing one embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a structure of two variable reactance elements different from FIG.

FIG. 3 is an explanatory diagram showing characteristics of a directional coupler used in the present invention.

FIG. 4 is a circuit diagram showing an embodiment of the present invention in a passing state.

FIG. 5 is a circuit diagram showing one embodiment of the present invention in a total reflection state.

FIG. 6 is an explanatory diagram showing an embodiment of an output power switching operation state in the present invention.

FIG. 7 is an explanatory diagram showing an example of a conventional switching procedure.

FIG. 8 is an explanatory diagram showing an example of a conventional output power switching operation state.

FIG. 9 is a circuit diagram showing another conventional example different from FIGS. 7 and 8;

[Explanation of symbols]

 1, 2 directional coupler 1A, 2A main line input terminal 1B, 2B main line output terminal 1C, 2C sub line coupling terminal 1D, 2D sub line non-coupling terminal 3 main line 4 sub line 5, 5A, 5B, 6, 6A, 6B T-type branch line 7, 8, 71, 81, 72, 82 T-branch stub 7A, 8A short-circuiting piece 7B, 8B choke 9 Simultaneous driving means 11, 12 Transmitter 13 Antenna 14 Pseudo load

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shinohara Kikuchi 1119 Nakayama-cho, Midori-ku, Yokohama-shi, Kanagawa Prefecture Inside Japan High-frequency Corporation (72) Inventor Takenori Mizuno 1119 Nakayama-cho, Midori-ku, Yokohama-shi, Kanagawa Japan Highway around Japan Nami Co., Ltd. F term (reference) 5K021 AA02 BB02 CC01 DD02 FF03 FF16

Claims (6)

[Claims] 1. An uninterruptible switching device for a transmitter output, wherein one antenna is connected to the output of one of a first and a second transmitter while being continuously connected to the other output.
A main line input terminal connecting one transmitter, a main line output terminal connecting a main line, a sub line coupling terminal connecting a sub line, and a non-coupling terminal connecting the antenna to one side and a pseudo load to the other side. Two directional couplers respectively, the main line connecting the main line output terminals of the two directional couplers, and the intermediate position of the sub-line connecting the sub-line coupling terminals, respectively. Two T-type branch lines to be provided, two variable reactance elements for changing the reactance in each of the two T-type branch lines, and one for changing the reactance value while maintaining each of the two variable reactance elements at the same value. An uninterruptible switching device for a transmitter output, comprising: a simultaneous driving unit. 2. The T-branch line according to claim 1,
An uninterruptible switching device for transmitter output, comprising a plurality of main lines and sub-lines provided at quarter-wave intervals. 3. The apparatus according to claim 1, wherein the variable reactance element forms at least one T-branch stub structure on the T-branch line. 4. The uninterruptible switching of a transmitter output according to claim 1, wherein the variable reactance element forms at least one mechanically plunger structure on the T-shaped branch line. apparatus. 5. The variable reactance element according to claim 1, wherein the variable reactance element has a choke structure on the T-shaped branch line, in which a movable portion is slightly apart from a metal wall surface. An uninterruptible switching device for a transmitter output, wherein one stage has a quarter wavelength. 6. The uninterruptible switching device for transmitter outputs according to claim 1, wherein the two transmitters have the same amplitude and phase when switching outputs. .