JPH11251929A - Waveguide matching device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain desired gain in the whole pass band of a waveguide and to eliminate the feedback amplification, oscillation and mix modulation of a wide band amplifier by providing a matching circuit where a high frequency in the pass band of the waveguide is caused to pass through the waveguide and the high frequency signal in a band except for the pass band of the waveguide is absorbed to a terminal unit. SOLUTION: A high frequency signal amplified by a wide band amplifier 1 is distributed into two by a 3db hybrid 4. Low pass filters 5 and 6 are constituted so that the high frequency signal out of a prescribed band is made to pass through. The high frequency signals outside the prescribed band among the inputted high frequency signals pass through the low pass filters 5 and 6 and are absorbed by terminal units 7 and 8. Since the high frequency signal of the prescribed band, namely, of not less than the cut off frequency of a waveguide antenna part 2, the high frequency signals of the band are reflected in the low pass filters 5 and 6, are inputted again to the hybrid 4 of 3dB being a distribution/synthesis circuit and are synthesized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waveguide matching device for electrically matching a waveguide with an amplifier for outputting a high-frequency signal to the waveguide.

[0002]

2. Description of the Related Art Generally, an amplifier connected to a waveguide (hereinafter referred to as a waveguide) constituting a horn antenna or the like includes:
A waveguide having a high gain (amplification factor) even in a frequency band outside the pass band of the waveguide is selected and used so that a desired gain can be obtained in the entire pass band of the waveguide. For example, FIG. 12 is a block diagram showing a conventional antenna device in which an antenna unit is configured by a horn antenna or the like. The prior art and the like of the present invention will be described using the antenna device as an example. In FIG. 12, reference numeral 1 denotes a high-gain broadband amplifier having a coaxial output terminal (not shown), and 2 denotes a predetermined passband characteristic provided with a coaxial waveguide converter (not shown). The waveguide antenna section 3 is a coaxial line such as a coaxial cable connecting the broadband amplifier 1 and the waveguide antenna section 2.

Accordingly, in the broadband amplifier 1, a signal (for example, a signal outside the pass band of the waveguide type antenna unit 2)
A noise signal which causes a spurious described later) is also amplified by the broadband amplifier 1 and output to the waveguide antenna unit 2. FIG. 13 is a characteristic explanatory diagram showing the relationship between the passband characteristic (lower stage) of the waveguide antenna unit 2 and the gain characteristic (upper stage) of the broadband amplifier 1.
As shown in FIG. 3, the broadband amplifier 1 is out of the pass band (out-of-band A or out of band) of the waveguide antenna unit 2 so that a predetermined gain (gain) can be obtained in the entire pass band of the waveguide antenna unit 2. Out of band B), those having a predetermined level of gain (amplification factor) are selected.

Further, in recent years, various communication systems using signals of various frequency bands, such as a portable radio system using a portable radio device, are in close proximity and coexist, and a conventional antenna as shown in FIG. In devices, the standard for suppressing unnecessary waves (spurious) by the Radio Law tends to be stricter.

[0005]

As described above, FIG.
In a conventional device consisting of a waveguide and a broadband amplifier as shown in FIG.
For example, it has a high level of gain even in a frequency band lower than the cut-off frequency of the waveguide (outside the band shown in FIG. 13: A). For example, a high-frequency signal in a frequency band lower than the cut-off frequency (for example, When a target signal including a spurious noise signal) is amplified by an amplifier and input to the waveguide, the waveguide is out of the predetermined band due to the deterioration of a VSWR (voltage standing wave ratio). The high-frequency signal is reflected at the input end of the waveguide, and the reflected high-frequency signal is feedback-amplified in the amplifier, oscillates, and furthermore, there is a problem that the oscillated wave and the target signal cause cross modulation. (Conversely, when an amplifier having a small gain in a region other than the above-mentioned predetermined band is selected, a desired gain can be obtained in the entire region within the predetermined band of the waveguide. There is a problem that had.).

In the case of an antenna device as shown in FIG. 12, oscillation and cross-modulation in the broadband amplifier 1 cause spurious (also called unnecessary waves), and the generated spurious is arranged around the antenna device. This causes a great obstacle to the operation of the communication device. Therefore, under the severe spurious conditions according to the Radio Law as described above, such a conventional antenna device is limited in its installation location in relation to other peripheral devices, or even if it is already installed. There are problems such as restrictions on the installation of other communication systems.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and removes a high-frequency signal outside a pass band of a waveguide amplified by a wide-band amplifier, thereby achieving a desired signal over the entire pass band of the waveguide. It is an object of the present invention to obtain a novel waveguide matching device that can obtain the gain of the above and can prevent feedback amplification and oscillation of a broadband amplifier based on a reflected signal from the waveguide, and further prevent cross-modulation and the like.

[0008]

According to a first aspect of the present invention, there is provided a waveguide matching device comprising: a waveguide; and a broadband amplifier having a predetermined level of gain in a wide frequency band including a pass band of the waveguide. Of the high-frequency signals amplified by the broadband amplifier, high-frequency signals in the pass band of the waveguide are passed through the waveguide, and high-frequency signals outside the pass band of the waveguide are passed to the terminator. And a matching circuit to be absorbed.

According to a second aspect of the present invention, there is provided a waveguide matching apparatus comprising:
A waveguide, a broadband amplifier having a predetermined level of gain in a wide frequency band including the passband of the waveguide, and a high-frequency signal amplified by the broadband amplifier, out of a passband of the waveguide. A high-frequency signal is passed and absorbed by the terminator, and a high-frequency signal in the predetermined pass band is blocked and the filter circuit blocks the passage, and the wide-band high-frequency signal is distributed and output to the filter circuit, And a distribution / synthesis circuit for synthesizing and outputting a high-frequency signal in the pass band cut off by the filter circuit to the waveguide.

According to a third aspect of the present invention, there is provided a waveguide matching device comprising:
An antenna section composed of a waveguide, a wideband amplifier having a predetermined level of gain in a wide frequency band including the passband of the antenna section, and a high-frequency signal amplified by the wideband amplifier outside a passband of the antenna section. And a filter circuit for passing the high-frequency signal in the terminal section and absorbing the high-frequency signal in the passband of the antenna section, and blocking the passage of the high-frequency signal in the pass band of the antenna section. And
And a distributing / synthesizing circuit for synthesizing and outputting a high-frequency signal in a pass band of the antenna section cut off by the filter circuit to the antenna section.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, an embodiment of the present invention will be described with reference to FIG. FIG. 1 is an embodiment of the present invention and is a block diagram showing a waveguide matching device of the present invention applied to an antenna device. The present invention relates to a waveguide matching device for electrically matching a waveguide with an amplifier, and is not limited to a device implemented in an antenna device.

In FIG. 1, reference numeral 4 denotes a waveguide type antenna unit 2 which divides the output power from the broadband amplifier 1 into two outputs and combines the signals reflected by a filter circuit described later.
3dB hybrid, which is a distribution / combination circuit that outputs
Bands 5 and 6 are set in accordance with the cut-off frequency of the waveguide type antenna unit 2 to be used, and frequency bands equal to or lower than the cut-off frequency which cause spurious generation (out-of-band shown in FIG. Low-pass filters, which are filter circuits configured to pass a high-frequency signal in the frequency band), are connected to the low-pass filters 5 and 6, respectively. It is a terminator that absorbs high frequency signals in the band. In the present embodiment, the filter circuit is configured by a low-pass filter because:
This is based on an experimental result that the cause of spurious generation is remarkable in a frequency band equal to or lower than the cutoff frequency of the waveguide type antenna unit 2, and is shown in FIG.
In order to remove signals in the frequency band shown in FIG.
It is called a predetermined band. ) Is constituted by a high-pass filter that passes only a high-frequency signal in a higher frequency band.

The low-pass filters 5 and 6 allow the terminators 7 and 8 to absorb the high-frequency signals in the frequency band equal to or lower than the cutoff frequency of the waveguide antenna unit 2 from the high-frequency signals distributed by the 3 dB hybrid 4. They have substantially the same characteristics, and have an electrical length 9 from the input terminal 4i of the 3dB hybrid 4 to the output terminal 40 of the 3dB hybrid 4 via the input terminal of the low-pass filter 5.
(Shown by a dashed line) and an electrical length 10 (shown by a dashed line) from the input end 4i of the 3dB hybrid 4 to the output end 40 of the 3dB hybrid 4 via the input end of the low-pass filter 6 are high-frequency signals at the time of power synthesis. In order to reduce the signal loss due to the phase shift, the electrical lengths are configured to be substantially equal. The same reference numerals in the drawings denote the same or corresponding parts, and a detailed description thereof will be omitted.

Next, the operation will be described. First, the high-frequency signal amplified by the broadband amplifier 1 is divided into two by the 3 dB hybrid 4 and input to the low-pass filters 5 and 6, respectively. As described above, the wideband amplifier 1 has a high gain even below the cutoff frequency of the waveguide antenna section 2, for example, a TWT (Travelling Wa).
Microphones such as ve tube) use an amplifier. Therefore, even if a target high-frequency signal is amplified in the wideband amplifier 1, the high-frequency signal output from the wideband amplifier 1 is out of a predetermined band (this embodiment). In the description of the form,
The pass band of the waveguide is called a predetermined band. ) Is amplified and output, for example, also for a noise signal.
Here, the low-pass filters 5 and 6 are configured to pass a high-frequency signal outside a predetermined band (in this embodiment, a frequency band equal to or lower than a cutoff frequency) that causes spurious noise. Among the high-frequency signals input to, the high-frequency signals outside the predetermined band pass through the low-pass filters 5 and 6 and are absorbed by the terminators 7 and 8, respectively.

A predetermined band of the high-frequency signals input to the low-pass filters 5 and 6, ie, the waveguide antenna unit 2,
, Cannot pass through the low-pass filters 5 and 6, and the high-frequency signals in the predetermined band are reflected at the input terminals of the low-pass filters 5 and 6, respectively, and are reflected by the 3 dB hybrid which is a distribution / synthesis circuit. 4 is input again and synthesized. The high-frequency signals reflected at the input ends of the low-pass filters 5 and 6 are combined by the 3 dB hybrid 4 and output to the air from the waveguide antenna unit 2 via the coaxial line 3.

As described above, according to the antenna apparatus as shown in FIG. 1, of the high-frequency signals output from the broadband amplifier 1, the high-frequency signals reflected by the waveguide antenna unit 2 and fed back and amplified by the wideband amplifier 1 are used. Since high-frequency signals below the cut-off frequency of the waveguide antenna unit 2 are absorbed by the terminators 7 and 8 via the low-pass filters 5 and 6, only high-frequency signals in a predetermined band that do not include noise signals and the like are waveguided. VSWR outside the predetermined band when the load side is viewed from the broadband amplifier 1 can be greatly improved. As a result, it is possible to prevent the oscillation that causes spurious and the cross modulation of the oscillating wave in the broadband amplifier 1 and the high-frequency signal in the predetermined band, and to output the high-frequency signal in the predetermined band with less influence of spurious to the air. Can be.

According to the present embodiment, the filter circuit is formed of a low-pass filter, and the target signal is output to the waveguide antenna unit 2 without passing through the filter circuit. Higher power (high power) as a whole with a strong configuration against power
It also has the advantage that it can be made into a product.

Embodiment 2 FIG. Next, another embodiment will be described with reference to FIG. FIG. 2 is a block diagram showing another embodiment of the present invention, showing a waveguide matching device applied to an antenna device. In the waveguide matching device of this embodiment, a high-pass filter whose band is set to pass a high-frequency signal in a predetermined band is used as a filter circuit. In FIG. 2, reference numeral 11 denotes a 3 dB hybrid, which is a first distribution / synthesis circuit that divides output power from the broadband amplifier 1 into two and outputs the divided power to a filter circuit described later.
Bands 2 and 13 are set in accordance with the cut-off frequency of the waveguide type antenna unit 2 to be used. High-frequency signals below this cut-off frequency which cause spurious generation are blocked from passing, and a predetermined band is set. A high-pass filter 14, which is a filter circuit configured to pass only a high-frequency signal of a predetermined band or more, combines high-frequency signals of a predetermined band passed through the high-pass filters 12 and 13 and is connected via the coaxial line 3. 3 dB hybrids, 15 and 16, which are second distribution / combination circuits that output to the waveguide type antenna unit 2, are terminators for isolation of the 3 dB hybrids 11, 14. The high-frequency signals outside the predetermined band reflected by the high-pass filters 12 and 13 are combined by the 3 dB hybrid 11 and then absorbed by the terminator 15.

In the antenna device of the present embodiment as well, of the high-frequency signals output from the broadband amplifier 1, the high-frequency signals lower than the cut-off frequency of the waveguide antenna section 2 are absorbed by the terminator 15, and the high-frequency signals of the predetermined band are absorbed. Since only the high-frequency signal can be output to the waveguide antenna section 2, the VSWR outside the predetermined band when the load side is viewed from the wideband amplifier 1 can be greatly improved, and the influence of spurious components can be further improved. High frequency signal of a predetermined band with a small value can be output in the air. Note that, in the antenna device of the present embodiment, in order to reduce signal loss due to a phase shift of a high-frequency signal at the time of power combining, a signal from the input terminal 11i of the 3dB hybrid 11 to the output terminal 140 of the 3dB hybrid 14 via the high-pass filter 12 is provided. Electric length 17 (shown by a dashed line) and input terminal 4 of 3 dB hybrid 11
The electrical length from i to the output end 140 of the 3 dB hybrid 14 via the high-pass filter 13 is set to be substantially equal to the electrical length (shown by a dashed line).

Embodiments (3) In the waveguide matching device of the above-described embodiment, the terminator absorbs a high-frequency signal outside a predetermined band (in the above-described embodiment, a frequency band equal to or lower than the cut-off frequency of the waveguide) by the distribution / synthesis circuit filter circuit. With this configuration, the VSWR outside the predetermined band when the load side is viewed from the wideband amplifier 1 can be significantly improved only by the filter circuit. In the following description of an embodiment, an antenna device having a circuit (hereinafter, referred to as a matching circuit) that can absorb a high-frequency signal other than a predetermined band output from a broadband amplifier 1 by a filter circuit in a terminator will be described. I do.

FIG. 3 is a block diagram showing a waveguide matching device applied to an antenna device according to another embodiment of the present invention. In FIG. 3, reference numeral 19 denotes a broadband amplifier 1 and a waveguide type antenna. A high-pass filter that is connected between the antenna unit 2 and a first filter circuit that outputs a high-frequency signal having a cut-off frequency or higher including a predetermined band of the waveguide antenna unit 2 to the waveguide antenna unit 2. , 20 are connected in parallel with the high-pass filter 19 to the coaxial line 3 between the wide-band amplifier 1 and the high-pass filter 19, and have a cut-off frequency equal to or lower than the cut-off frequency of the waveguide antenna unit 2 reflected at the input end of the high-pass filter 19. A low-pass filter 21, which is a second filter circuit for passing a high-frequency signal, is connected to an output terminal of the low-pass filter 20, and the low-pass filter 2
This is a terminator that absorbs a high-frequency signal that is equal to or lower than the cut-off frequency of the waveguide antenna unit 2 that has passed through zero. According to the antenna device of the present embodiment, since the high-frequency signal outside the required band is reflected by the input end of the high-pass filter 19 and absorbed by the terminator 21 through the low-pass filter 20, the high-frequency signal outside the predetermined band causes It is possible to prevent a situation in which the amplifier 1 oscillates, and furthermore, this oscillation wave and a high-frequency signal in a target predetermined band are cross-modulated, so that the occurrence of spurious can be greatly reduced.

Embodiment. 4. In the antenna device according to the above embodiment, the broadband amplifier 1
High-pass filter 19 between the
However, the high-pass filter 19 may be replaced with a band-pass filter having a pass band similar to the pass band of the waveguide antenna unit 2. According to this embodiment, even when a noise signal occurs in a frequency band (out-of-band: B) that is equal to or higher than the predetermined band shown in FIG. 13, the occurrence of spurious noise can be significantly reduced. FIG. 4 is a block diagram showing a waveguide matching device applied to an antenna device according to another embodiment of the present invention. In FIG. 4, reference numeral 22 denotes a band-pass filter which is a first filter circuit in which a pass band similar to the frequency band used by the waveguide antenna unit 2 is set, and reference numeral 23 denotes a frequency higher than the pass band of the band-pass filter 22. This is a high-pass filter that is a second filter circuit that passes a signal in the band and absorbs the signal in the terminator 24. In the drawings, the same reference numerals indicate the same or corresponding parts.

In this embodiment, not only signals in the frequency band equal to or lower than the cutoff frequency but also high-frequency signals other than the required band (out-of-band: A and out-of-band: B in FIG. 13) are band-pass filters. The terminal 2 is reflected by the input terminal of the second terminal 22 through a low-pass filter 20 or a high-pass filter 23 as a second filter circuit.
Since the high frequency signal outside the predetermined band of the waveguide type antenna unit 2 oscillates, the oscillated wave and the high frequency signal within the target predetermined band are separated. The situation of cross modulation can be prevented, and the occurrence of spurious can be greatly reduced. When spurious can be significantly reduced only by removing a signal in a frequency band equal to or lower than the cutoff frequency, the second filter circuit may be configured with the low-pass filter 20 alone.

Embodiments 5. In the waveguide matching device according to the above embodiment, the band-pass filter 22 is provided instead of the high-pass filter 19, but the stop band oscillates in a band equal to or lower than the cut-off frequency of the waveguide antenna unit 2. The band may be replaced with a band rejection filter whose frequency satisfies the pass band of the waveguide antenna unit 2. FIG. 5 is a block diagram showing a waveguide matching device applied to an antenna device according to another embodiment of the present invention. In FIG. This is a band rejection filter which is a first filter circuit in which a satisfactory pass band is set.

Also in this embodiment, a high-frequency signal other than a required band is reflected by an input terminal of a band rejection filter 25 serving as a first filter circuit, and is passed through a low-pass filter 20 or a high-pass filter 23 serving as a second filter circuit. The broadband amplifier 1 oscillates with a high-frequency signal outside the predetermined band of the waveguide type antenna unit 2 and can be absorbed by the terminators 21 and 24 via the terminators 21 and 24. It is possible to prevent the situation that the high frequency signal is intermodulated,
Spurious generation can be significantly reduced.

Embodiment. 6. In the waveguide matching device according to the third embodiment, the low-pass filter 20 is used as a second filter circuit that causes the terminator 21 to absorb a high-frequency signal in a frequency band equal to or lower than the cutoff frequency reflected at the input end of the high-pass filter 19. Although provided, it is limited to a certain frequency band below the cutoff frequency of the waveguide type antenna unit 2 (frequency band where a signal causing oscillation in the wideband amplifier 1 exists), and the VSWR in a band near the frequency band is improved. A filter circuit may be configured by a band-pass filter to be used. FIG. 6 is a block diagram showing a waveguide matching device applied to an antenna device according to another embodiment of the present invention. In FIG. The VSW is limited to a frequency oscillating in a band equal to or lower than the cutoff frequency of the antenna unit 2 and only in a band near the frequency band.
This is a bandpass filter that improves R.

In the present embodiment, of the high-frequency signals other than the required band reflected by the input terminal of the high-pass filter 19 as the first filter circuit, the high-frequency signal in the band equal to or lower than the cut-off frequency of the waveguide antenna unit 2. Since the high-frequency signal in the band near the oscillating frequency band is absorbed by the terminator 21 through the band-pass filter 26 serving as the second filter circuit, the high-frequency signal out of the required band other than the required band reflected by the input terminal is output. A high-frequency signal in a band near a frequency band oscillating in a band equal to or lower than the cut-off frequency of the waveguide antenna unit 2 is absorbed by the terminator 21 via a band-pass filter 26 serving as a second filter circuit. Therefore, the broadband amplifier 1 oscillates by a high-frequency signal in a band near the frequency band oscillating in a band equal to or lower than the cutoff frequency of the waveguide antenna unit 2, and This oscillation wave and the signal of interest can be prevented from being intermodulation, the spurious can be reduced significantly.

Embodiment. 7. In the antenna device according to the above embodiment, the antenna device according to the above embodiment. As in 4 or 5, instead of the high-pass filter 19, a band-pass filter whose pass band is set to be substantially the same as the pass band of the waveguide antenna unit 2 may be used. FIG. 7 is a block diagram showing a waveguide matching device applied to an antenna device according to another embodiment of the present invention.

In the present embodiment, not only signals in a frequency band below the cutoff frequency but also high-frequency signals outside the required band are reflected by the input terminal of the band-pass filter 22, which is the first filter circuit. Of the high-frequency signals other than the required band reflected by the filter, a high-frequency signal in a band near a frequency band oscillating in a band equal to or lower than the cut-off frequency of the waveguide antenna unit 2 is a band-pass filter serving as a second filter circuit. Since the signal is absorbed by the terminator 21 via the filter 26, the broadband amplifier 1 oscillates by a high-frequency signal in a band near a frequency band oscillating in a band equal to or lower than the cutoff frequency of the waveguide antenna unit 2, and It is possible to prevent the oscillating wave and the target signal from being cross-modulated, and it is possible to greatly reduce the occurrence of spurious.

Embodiment. 8 In the antenna device according to the above embodiment, the band-pass filter 22 is provided instead of the high-pass filter 19. However, as shown in FIG. Among them, the band may be replaced by a band rejection filter whose pass band satisfies the frequency band used by the waveguide antenna unit 2. FIG. 8 shows another embodiment of the present invention, and is a block diagram showing a waveguide matching device applied to an antenna device.

In the present embodiment, of the high-frequency signals other than the required band reflected by the input terminal of the band rejection filter 25 as the first filter circuit, the high-frequency signal having the cut-off frequency equal to or lower than the cut-off frequency of the waveguide antenna unit 2 is used. Since the high-frequency signal in the band near the frequency band oscillating in the band is absorbed by the terminator 21 via the band-pass filter 26 as the second filter circuit, the cut-off frequency is equal to or lower than the cut-off frequency of the waveguide antenna unit 2. High frequency signal is oscillated, and the high frequency signal in the predetermined band which is feedback-amplified by the wideband amplifier 1 and the reflected signal can be prevented from being intermodulated, and the occurrence of spurious can be greatly reduced. it can.

Embodiment 9. The above embodiment. 6, the band-pass filter 26 connected in parallel with the high-pass filter 19 is provided on the coaxial line 3 between the wide-band amplifier 1 and the high-pass filter 19, but instead of this band-pass filter 24. The frequency band used by the waveguide antenna unit 2 may be a stop band, and a frequency band other than the frequency band used by the waveguide antenna unit 2 may be replaced with a band rejection filter set as a pass band. . FIG. 9 is a block diagram showing a waveguide matching device applied to an antenna device according to another embodiment of the present invention. Reference numeral 27 denotes a band rejection filter.

Also in the present embodiment, of the high-frequency signals other than the required band reflected by the input terminal of the high-pass filter 19 as the first filter circuit, the high-frequency signals in the band equal to or lower than the cut-off frequency of the waveguide antenna unit 2. A high-frequency signal in a band near the oscillating frequency band is passed through a band rejection filter 27 as a second filter circuit to the terminator 2.
1, the broadband amplifier 1 oscillates with a high-frequency signal in a band near the frequency band oscillating in a band equal to or lower than the cut-off frequency of the waveguide antenna unit 2, and the oscillated wave and the intended wave It is possible to prevent cross-modulation with a high-frequency signal, and it is possible to significantly reduce spurious generation.

Embodiment 10. The antenna device according to the present embodiment is the same as the embodiment shown in FIG. 7, the band pass filter 26 of the antenna device using the waveguide antenna unit 2 is set as a stop band, and a band other than the used frequency band of the waveguide antenna unit 2 is set as a pass band. Function filter. FIG. 10 shows another embodiment of the present invention, and is a block diagram showing a waveguide matching device applied to an antenna device. Also in the present embodiment, the high-frequency signal outside the predetermined band reflected at the input end of the band-pass filter 22 as the first filter circuit is sent to the terminator 21 via the band rejection filter 27 as the second filter circuit. Since it can be absorbed, the generation of spurious can be greatly reduced.

Embodiments 11 The antenna device according to the present embodiment is similar to the antenna device shown in FIG. 8, the band pass filter 26 of the antenna device is used as a stop band in a frequency band used by the waveguide type antenna unit 2, and a band rejection frequency band other than the frequency band used in the waveguide type antenna unit 2 is set as a pass band. It is replaced with an action filter 27. FIG. 11 is a block diagram showing a waveguide matching device applied to an antenna device according to another embodiment of the present invention. Also in the present embodiment, the high-frequency signal outside the predetermined band reflected at the input terminal of the band rejection filter 25 serving as the first filter circuit is passed through the terminator 21 via the band rejection filter 27 serving as the second filter circuit. Therefore, the occurrence of spurious can be greatly reduced. .

[0036]

According to the first aspect of the present invention, a waveguide, a wideband amplifier having a predetermined level of gain in a wide frequency band including a passband of the waveguide, and a signal amplified by the wideband amplifier. Since a high-frequency signal within the pass band of the waveguide among the high-frequency signals is passed through the waveguide, and a high-frequency signal outside the pass band of the waveguide is provided with a matching circuit that is absorbed by a terminator. The high-frequency signal other than the required band is absorbed by the terminator, a desired gain is obtained in the entire pass band of the waveguide, and the wide-band amplifier oscillates. This can be prevented relatively easily.

According to the second aspect of the present invention, a waveguide, a wide-band amplifier having a predetermined level of gain in a wide frequency band including a pass band of the waveguide, and a high-frequency signal amplified by the wide-band amplifier A filter circuit that passes a high-frequency signal outside the pass band of the waveguide and absorbs the high-frequency signal within the predetermined pass band, and blocks the passage of a high-frequency signal within the predetermined pass band; A distribution / combination circuit that distributes and outputs signals to the filter circuit, and combines and outputs a high-frequency signal in the pass band cut off by the filter circuit to the waveguide. The high-frequency signal is absorbed by the terminator, and the desired gain is obtained in the entire pass band of the waveguide, and the wide-band amplifier oscillates. It can be relatively easily prevented a situation that causes signals and cross-modulation of the excitation wave and the target.

According to the third aspect of the present invention, an antenna section comprising a waveguide, a wide band amplifier having a predetermined level of gain in a wide frequency band including a pass band of the antenna section, and an amplifier amplified by the wide band amplifier. A filter circuit that passes a high-frequency signal outside the pass band of the antenna unit and absorbs the high-frequency signal within a pass band of the antenna unit, and blocks the passage of a high-frequency signal within the pass band of the antenna unit; And a distributing / synthesizing circuit for distributing and outputting the high frequency signal to the filter circuit, and for synthesizing and outputting the high frequency signal in the pass band of the antenna section cut off by the filter circuit to the antenna section. Therefore, high-frequency signals outside the required band, which cause spurious, are absorbed by the terminator and pass through the waveguide. A desired gain can be obtained in the entire range, and a wideband amplifier can oscillate, and furthermore, it is possible to relatively easily prevent a situation in which this oscillation wave and a target signal are cross-modulated. The spurious of the high-frequency signal output from the unit into the air can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a waveguide matching device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a waveguide matching device according to another embodiment of the present invention.

FIG. 3 is a configuration diagram of a waveguide matching device according to another embodiment of the present invention.

FIG. 4 is a configuration diagram of a waveguide matching device according to another embodiment of the present invention.

FIG. 5 is a configuration diagram of a waveguide matching device according to another embodiment of the present invention.

FIG. 6 is a configuration diagram of a waveguide matching device according to another embodiment of the present invention.

FIG. 7 is a configuration diagram of a waveguide matching device according to another embodiment of the present invention.

FIG. 8 is a configuration diagram of a waveguide matching device according to another embodiment of the present invention.

FIG. 9 is a configuration diagram of a waveguide matching device according to another embodiment of the present invention.

FIG. 10 is a configuration diagram of a waveguide matching device according to another embodiment of the present invention.

FIG. 11 is a configuration diagram of a waveguide matching device according to another embodiment of the present invention.

FIG. 12 is a configuration diagram of a conventional device.

FIG. 13 is a diagram illustrating characteristics of a conventional device.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 broadband amplifier 2 waveguide antenna unit 3 coaxial line 4 3 dB hybrid 5, 6 low-pass filter 7, 8, 15, 16, 21, 24 terminator 12, 13 high-pass filter 19 high-pass filter (first filter circuit) 20 Low-pass filter (second filter circuit) 22 band-pass filter (first filter circuit) 23 high-pass filter (second filter circuit) 25 band rejection filter (first filter circuit) 26 band-pass filter (second filter circuit) Filter circuit) 27 Band rejection filter (second filter circuit)

Claims (3)

[Claims] 1. A waveguide, a wide-band amplifier having a predetermined level of gain in a wide frequency band including a pass band of the waveguide, and a high-frequency signal amplified by the wide-band amplifier, A matching circuit for passing a high-frequency signal in a pass band through the waveguide and absorbing a high-frequency signal outside the pass band of the waveguide in a terminator. . 2. A waveguide, a wide-band amplifier having a predetermined level of gain in a wide frequency band including a pass band of the waveguide, and the waveguide of the high-frequency signal amplified by the wide-band amplifier. A high-frequency signal outside the pass band is passed through and absorbed by the terminator, and a high-frequency signal within the predetermined pass band is cut off by the filter circuit. And a distribution / synthesis circuit for synthesizing and outputting, to the waveguide, a high-frequency signal in the pass band cut off by the filter circuit. 3. An antenna section comprising a waveguide, a wide-band amplifier having a predetermined level of gain in a wide frequency band including a pass band of the antenna section, and the antenna among high-frequency signals amplified by the wide-band amplifier. A filter circuit that allows high-frequency signals outside the pass band of the unit to pass through and is absorbed by the terminator, and blocks high-frequency signals within the pass band of the antenna unit from passing therethrough;
A distributing / combining circuit that distributes and outputs the wideband high-frequency signal to the filter circuit, and that combines and outputs a high-frequency signal in a pass band of the antenna unit cut off by the filter circuit to the antenna unit; A waveguide matching device comprising: