JP2006333378A - Transmitter with thunder surge reduction function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmitter with a thunder surge reduction function capable of easing rapid voltage change by the spark, suppressing a generation of high-frequency noise, raising thunder surge proof level, and preventing a breakage of amplifer elements by solving problem that the conventional transmitter cannot remove the high-frequency noise based on a rapid falling waveform originating in the spark generated in connection with thunder surge and has an inadequate thunder surgeproof level. <P>SOLUTION: The transmitter with a thunder surge reduction function has BPF 4 inserted with connection at each output of two or more power amplifiers 3, a surge absorber 7 connected between a synthesizer 5 and a tuned matching circuit 6, a DC cut capacitor 8 inserted with connection between the tuned matching circuit 6 and antenna 9, and a coil 11 connected to the grounding side of the ball gap 10 in series in addition to the ball gap (surge arrester) 10 connected to the input of the antenna. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a short-wave transmitter (regardless of solidification or vacuum tube type), and particularly suppresses and reduces lightning surge mixed from an aerial so that even if a spark occurs inside the device, it can be sufficiently suppressed. The present invention relates to a transmitter with a lightning surge reduction function capable of improving tolerance.

In a solid-state transmitter using a semiconductor element as a power amplifier, the semiconductor may be damaged by a lightning surge (induced lightning, direct lightning, etc.) mixed from an antenna.
As a transmitter for reducing lightning surge, there has been a transmitter in which a DC cut capacitor or a lightning arrester is inserted in the transmitter output, or a BPF that suppresses a low frequency component is provided in the output of the power amplifier.

FIG. 3 is a configuration block diagram of a conventional solid-state transmitter.
As shown in FIG. 3, a conventional solid-state transmitter includes a signal control circuit 1 that modulates an input signal, a distributor 2 that distributes the modulated input signal into a plurality, and a plurality of signals that amplify the signal to a required level. Power amplifiers (PA) 3-1 to 3-n, a band-pass filter (BPF; band-limiting filter) 4-1 to 4-n that passes only a specific frequency band (emission frequency), and a plurality of BPFs 4 A synthesizer 5 that synthesizes the output signal, a tuning matching circuit 6 that matches the antenna and removes the high frequency of the synthesized output, a surge absorber 7 that is a circuit that absorbs lightning surge, and a direct current component of the surge current The DC cut capacitor 8 is used to remove the signal and the antenna 9 radiates the output signal of the transmitter into the air. Although not shown here, a lightning arrester may be provided after the DC cut capacitor 8.

  Among the above components, a semiconductor element such as an FET is used as the power amplifier 3. As the tuning matching circuit 6, a low pass filter (LPF) is generally used in order to reduce harmonics and match the antenna impedance.

  Further, the surge absorber 7 is of a semiconductor type or a bias application type, and absorbs a low frequency component of the surge current but cannot suppress a high frequency component. The BPF 4 has a function of removing a low frequency component of the surge current, and is provided for protecting each power amplifier 4.

  In the transmitter, the input signal is modulated by the signal control circuit 1, distributed to n power amplifiers 3 by the distributor 2, and amplified by each power amplifier 3. Only the output frequency band of the transmitter is extracted by the BPF 4 by the BPF 4, synthesized in the synthesizer 5, matched with the antenna via the tuning matching circuit 6, and emitted from the antenna 9 as an output signal. It has become.

Next, the influence of the lightning surge in the conventional solidified transmitter will be described with reference to FIG. FIG. 4 is a schematic explanatory view showing the influence of lightning surge in a conventional transmitter.
The transmitter shown in FIG. 4 includes a ball gap 10 as a lightning arrester after the DC cut capacitor 8 in addition to the configuration of the transmitter shown in FIG.

  When a lightning surge is mixed from the aerial line 9 and the voltage of the lightning surge is high, a spark (spark) may occur between the components of the tuning matching circuit 6 and the ball gap 10. The example of FIG. 4 shows a case where a spark occurs between the ball gaps.

  For example, when a lightning surge on the + side enters from the antenna and a spark occurs between the ball gaps, the surge waveform rises sharply to the + side and then becomes a sharp falling waveform (see FIG. 4 (e)). ). This waveform is converted into a large high frequency component by the action of the coil and the capacitor while passing through the DC cut capacitor 8 and the tuning matching circuit 6, but the noise of the high frequency component is absorbed by the surge absorber 7 as described above. This is not done (see FIG. 4 (f)).

Therefore, the high frequency noise that has not been reduced by the surge absorber 7 passes through the passband of the synthesizer 5 and the BPF 4 and is mixed into the power amplifier 3 as it is (see FIG. 4G). Caused damage. This high-frequency lightning surge becomes larger as the spark voltage becomes higher.
In addition, although demonstrated using the ball gap here, the same thing happens when other lightning arresters are used or when sparks occur in the parts of the matching tuning circuit 6.

As a conventional technology for lightning surge countermeasures of solid-state shortwave transmitters, Japanese Patent Application Laid-Open No. 10-112661 “Thinning surge reduction method for solid-state shortwave transmitters” (Applicant: Kokusai Electric) Co., inventor: Shigeru Kawamura).
In this prior art, an HPF that passes a short-wave band frequency and attenuates a low lightning surge frequency band is inserted and connected before the tuning matching circuit on the output side of the combiner of the power amplifier. The lightning surge applied to the power amplifier can be attenuated while maintaining the impedance matching.

Japanese Patent Laid-Open No. 10-112661

  However, the conventional transmitter cannot remove high-frequency noise generated from a sudden falling waveform due to sparks, may damage the semiconductor amplifying element, and has insufficient lightning surge resistance. There was a problem.

  The present invention has been made in view of the above circumstances, and mitigates rapid voltage changes derived from sparks generated by lightning surges, suppresses the generation of high-frequency noise, and improves the lightning surge resistance of the transmitter. It is an object of the present invention to provide a transmitter with a lightning surge reduction function that can prevent damage to an amplification element.

  The present invention for solving the problems of the above-described conventional example includes a distributor for distributing an input transmission signal, a plurality of power amplifiers for amplifying the distributed signals, and each of the amplified signals. A transmitter comprising a combiner for combining, a tuning and matching circuit for tuning the combined signal to an antenna, and an antenna for radiating an output signal, wherein the transmitter is inserted and connected to each output of a plurality of power amplifiers. It is connected between a bandpass filter that passes signals in the frequency band, a synthesizer, and a tuning matching circuit, and is inserted and connected between a surge absorber that absorbs surge power caused by lightning surges, and a tuning matching circuit and an antenna. And a DC cut capacitor for removing a DC component, a lightning arrester connected to the input of the antenna, and a coil connected in series to the ground side of the lightning arrester.

  According to the present invention, a distributor that distributes an input transmission signal, a plurality of power amplifiers that respectively amplify the distributed signals, a combiner that combines the amplified signals, A transmitter having a tuning and matching circuit that tunes a signal to an antenna and an antenna that radiates an output signal. The transmitter is inserted and connected to the output of each of a plurality of power amplifiers, and passes a signal in a specific frequency band. DC filter that is connected between the filter, the synthesizer, and the tuning matching circuit, and absorbs surge power caused by lightning surge, and is inserted between the tuning matching circuit and the antenna, and removes the DC component. And a lightning surge reduction transmitter with a lightning arrester connected to the antenna input and a coil connected in series to the grounding side of the lightning arrester. Even if an internal spark occurs, the coil inductance prevents the surge waveform from abruptly rising / falling to suppress high-frequency noise and suppresses surge power as low-frequency noise only. As a result, it is possible to improve the resistance and safety of the transmitter and to improve the reliability of the transmitter.

Embodiments of the present invention will be described with reference to the drawings.
A transmitter with a lightning surge reduction function according to the present invention is a transmitter in which an input signal is distributed, amplified by a plurality of power amplifiers, synthesized, tuned and matched with the antenna, and output from the antenna as a transmission signal. A BPF provided at the outputs of a plurality of power amplifiers, a surge absorber provided at the output of the combiner, a DC cut capacitor provided at the input of the antenna, and a lightning arrester connected to the input of the antenna In addition, a coil inserted and connected in series between the lightning arrester and GND is provided, and the fall of the voltage due to the spark generated by the lightning surge is moderated by the coil inductance to generate high-frequency noise. It is possible to suppress only low-frequency noise that can be sufficiently suppressed, prevent damage to the power amplifier semiconductor, and improve lightning surge resistance and safety. It is intended.

A transmitter with a lightning surge reduction function according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a configuration block diagram showing a configuration of a transmitter according to an embodiment of the present invention. The same components as those in FIGS. 3 and 4 will be described using the same reference numerals.
As shown in FIG. 1, the transmitter (this device) according to the embodiment of the present invention has almost the same basic configuration as the conventional solid-state transmitter shown in FIG. Are a signal control circuit 1, a distributor 2, a power amplifier (PA) 3, a BPF 4, a combiner 5, a tuning and matching circuit 6, a surge absorber 7, a DC cut capacitor 8, and an antenna. 9 and a ball gap 10 (not shown in FIG. 3) as a lightning arrester. Further, as a characteristic part of the present invention, a coil 11 connected in series to the ground side of the ball gap is provided. In place of the ball gap 10, a vacuum arrester or a gas arrester may be used.

  The coil 11 of the present invention is connected in series to the ball gap 10 and the other end is grounded. The coil 11 suppresses a rapid voltage change that occurs when a spark occurs in the ball gap 10 to prevent a sudden voltage drop, thereby suppressing the generation of high-frequency noise.

  Thus, in this device, even if a spark occurs in the ball gap 10 (or lightning arrester) due to a lightning surge, the generation of high frequency noise is prevented, the high frequency is prevented from entering the power amplifier 3, and the power amplifier is prevented from being damaged. It is something that can be done.

Next, the influence of lightning surge in the transmitter according to the embodiment of the present invention will be described with reference to FIG. FIG. 2 is a schematic explanatory view showing the influence of lightning surge in the present apparatus.
As shown in FIG. 2, when + lightning surge is mixed from the antenna 9, a spark may occur in the ball gap 10, but in this transmitter, the coil 11 is connected to the ball gap 10. The rapid change of the voltage is suppressed by the inductance of the coil 11 and the power supply impedance of the lightning surge from the antenna 9, and the rise and fall of the surge waveform at the time of spark become gentle (see FIG. 2A).

  Since the surge waveform shown in (a) does not fall sharply, it is not converted into high-frequency noise by a capacitor or coil while passing through the DC cut capacitor 8 and the tuning matching circuit 6. Only frequency noise is generated (see FIG. 2B).

  Then, the waveform of (b) consisting of low frequency noise is partially absorbed by the surge absorber 7 and then further suppressed by each BPF 4 provided at the output of each power amplifier 3 (FIG. 2 (c)). reference). As described above, the surge absorber 7 and the BPF 4 cannot reduce high-frequency noise but can sufficiently suppress low-frequency noise. Thereby, the noise due to the spark can be made sufficiently small before reaching the power amplifier 3.

  For this reason, even if a lightning surge enters from the aerial 9 and a spark is generated in a lightning arrester or a tuning matching circuit component in the apparatus, this transmitter generates a high-frequency noise by slowing the fall by the action of the coil 11. Thus, only low frequency noise that can be sufficiently suppressed can be obtained, the semiconductor of the power amplifier 3 can be prevented from being damaged, and the lightning surge resistance and safety of the transmitter can be improved.

  According to the transmitter with the lightning surge reduction function according to the embodiment of the present invention, the input signal is distributed by the distributor 2, each distributed signal is amplified by the power amplifier 3, and the amplified signal is amplified. Is synthesized by the synthesizer 3 and is tuned and matched with the antenna by the tuning matching circuit 6 and then transmitted as a transmission output, and the BPF 4 inserted and connected to each output of the plurality of power amplifiers 3 and the synthesizer 5 And a tuned matching circuit 6, a surge absorber 7, a DC cut capacitor 8 inserted and connected between the output tuned matching circuit 6 and the antenna 9, and a ball gap 10 connected to the antenna input. And a coil 11 connected in series on the ground side of the ball gap 10, and when a lightning surge is mixed from the antenna 9, a surge wave is generated by the inductance of the coil 11 even if a spark occurs in the device. By slowing the fall of the signal, preventing the generation of high-frequency noise and making only low-frequency noise, and suppressing the low-frequency noise by the surge absorber 7 and the BPF 4, the surge power reaching the power amplifier 3 can be made sufficiently small. Can be prevented, and the resistance and safety against the lightning surge of the transmitter can be improved.

  Here, the solid-state transmitter using a semiconductor element as the power amplifier 3 has been described. However, the transmitter using a vacuum tube also generates high-frequency noise by providing a coil in the same manner as in the above-described example. This can prevent the lightning surge and improve the lightning surge resistance and safety.

  The present invention provides a transmitter with a lightning surge reduction function capable of suppressing and reducing lightning surge mixed from an aerial so that it can be sufficiently suppressed even if a spark is generated inside the transmitter and can improve resistance to lightning surge. Is suitable.

It is a block diagram which shows the structure of the transmitter which concerns on embodiment of this invention. It is a schematic explanatory drawing which shows the influence of the lightning surge in this apparatus. It is a block diagram of a conventional transmitter. It is a schematic explanatory drawing which shows the influence of the lightning surge in the conventional transmitter.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Signal control circuit, 2 ... Divider, 3 ... Power amplifier (PA), 4 ... Band pass filter (BPF), 5 ... Synthesizer, 6 ... Tuning matching circuit, 7 ... Surge absorber, 8 ... DC cut capacitor , 9 ... Antenna, 10 ... Ball gap, 11 ... Coil

Claims (1)

A distributor for distributing an input transmission signal;
A plurality of power amplifiers each amplifying the distributed signal;
A synthesizer for combining the amplified signals;
A tuning matching circuit for tuning the synthesized signal to an antenna;
A transmitter with an antenna that emits an output signal,
A band-pass filter that is inserted and connected to the output of each of the plurality of power amplifiers and allows a signal in a specific frequency band to pass;
A surge absorber connected between the combiner and the tuned matching circuit and absorbing surge power caused by lightning surge;
A DC cut capacitor that is inserted and connected between the tuning matching circuit and the antenna and removes a DC component;
A lightning arrester connected to the input of the antenna;
A transmitter with a lightning surge reduction function, comprising: a coil connected in series to the ground side of the lightning arrester.

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