JPH0151081B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a wideband antenna device that obtains wideband transmission and reception characteristics by using three or more antennas that are mounted on the same rotary table and have continuous operating bands.

[Technical background of the invention and its problems] FIG. 1 shows a wideband antenna device using, for example, three antennas. antenna 1
1, 12, 13 are antennas whose frequency bands are continuous, and these antennas 11, 12, 13
The frequency bands used are F ₁ ~ F ₂ , F ₂ ~ _{F 3} , respectively.
It is set as F ₃ to F ₄ . These antennas 1
1, 12, and 13 are rotary joints 1 that are provided on the same rotary table (not shown) and have the same number of branch terminals (hereinafter referred to as channels) as antennas.
4 to a transmission/reception system (not shown).
In this way, there is no problem when the number of antennas is small, but when the number of antennas increases, the characteristics such as insertion loss and VSWR of each channel will deteriorate with the rotary joint as described above, and the size will also increase. I have a problem.

Therefore, in order to reduce the number of channels of the rotary joint, conventionally the antennas 11, 12, 13 are connected to a triplexer 21 as shown in FIG. A configuration connecting the antennas 12 and 13 to a transmitting/receiving system, or as shown in FIG.
1 through 2 channel rotary joint 3
Connect to one channel on the rotating side of antenna 1.
1 is directly connected to the other rotary side channel of the rotary joint 32, and a diplexer 3 is connected to the fixed side channel of the rotary joint 32 corresponding to the diplexer 31.
3, and the other channel on the fixed side of the rotary joint 32 corresponding to the antenna 11 is directly connected to the transmitting and receiving system. Note that the crossover frequency of the triplexer 21 is the same as that of the antennas 11, 12, 13.
The crossover frequencies of the diplexers 31 and 33 are set at the boundaries of the frequency bands used by the antennas 12 and 13.

By the way, triplexer 21 and diplexer 3
The loss at the crossover frequency of 1 and 33 is 4 to 5 dB, and in the configuration shown in Figure 3, the loss at the frequency F ₃
Due to the provision of two diplexers, an insertion loss of 8 to 10 dB in the vicinity of the antenna feeding system was unavoidable as shown in FIG. This is the crossover frequency F ₂ of the configuration shown in FIG.
The same was true for _F3 , which was a problem in obtaining broadband characteristics.

[Purpose of the invention]

This invention has been made based on the above circumstances, and it is possible to connect a plurality of antennas whose frequency bands are continuous to a transmitting/receiving system without increasing loss at the crossover frequency, and to obtain excellent common band characteristics. The aim is to provide a wideband antenna device that is capable of

[Summary of the invention]

For example, the present invention divides a plurality of antennas with continuous frequency bands into N groups (N≧2) of antennas with non-adjacent frequency bands, and connects the rotating side of a rotary joint having the same number of channels as the number of groups. A first multiplexer is provided on the fixed side to which the grouped antennas are connected, and a second multiplexer is provided on the fixed side to which the transmitting/receiving system is connected. By setting it outside the band, it is intended to obtain excellent broadband characteristics.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to side views. Note that the same parts as in FIGS. 1 to 3 are denoted by the same reference numerals.

In FIG. 5, antennas 11, 12, and 13 are arranged on the same rotary table, and each has a continuous operating frequency band _F1 to _F2 , _F2 to _F3 , and _F3 to _F4. . Among these antennas 11, 12, and 13, antenna 1 whose operating frequency bands are not adjacent to each other
1, 13 and antennas 12 are divided into two groups, and antennas 11, 13 are connected to a first multiplexer, for example a diplexer 51. The crossover frequency of this diplexer 51 is set within the frequency band used by the antennas 12 of another group, that is, within F ₂ to F ₃ . This diplexer 5
The common terminals of the antennas 12 and 1 are respectively connected to the rotation side channels of the rotary joint 52. Further, between the fixed side channel of this rotary joint 52 and the transmission/reception system, a second multiplexer, for example, a diplexer 53 whose crossover frequency is set to be the same as that of the diplexer, is connected to the channel corresponding to the diplexer 51. Ru.

According to the above configuration, the antennas 11 and 13 whose frequency bands are not adjacent to each other are the diplexers 51 and 53.
The other antennas 12 are connected to the transmitting/receiving system via the rotary joint 52. Furthermore, the crossover frequencies of the diplexers 51 and 53 are set within the band of the antenna 12. Therefore, each frequency band used is the 6th frequency band.
As shown in the figure, there is no effect of loss due to the crossover frequency.

Next, other embodiments of the invention will be described. In Fig. 7, the frequency bands used are F ₁ to F ₂ , F ₂ to _{F 3} ,
Five antennas 7: F ₃ ~ F ₄ , F ₄ ~ F ₅ , F ₅ ~ _{F 6}
1,72-75 are used. These antennas 71, 72 to 75 are provided on the same rotary table, and similar to the above, antennas whose operating frequency bands are not adjacent to each other are grouped. That is, antenna 7
1, 73, and 75 are considered as one group, and these antennas 71, 73, and 75 are connected to a triplexer 76.
connected to. Further, the antennas 72 and 74 are made into one group, and these antennas 72 and 74
is connected to diplexer 77. The common terminals of the diplexer 77 and the triplexer 76 are respectively connected to the rotation side channels of a rotary joint 78 having the same number of channels as the number of groups. A common terminal of a triplexer 79 and a diplexer 80 corresponding to the triplexer 76 and diplexer 77 is connected to the fixed side channel of the rotary joint 78, and a transmitting/receiving system is connected via the triplexer 79 and diplexer 80. In addition, these triplexers 7
The crossover frequencies 6 and 79 are set within the frequency bands used by the antennas of other groups, that is, within the ranges of _F2 to _F3 and _F4 to _F5 . Further, the crossover frequencies of the diplexers 77 and 80 are similarly set within the range of F ₃ to F ₄ . With such a configuration, each antenna 7 as shown in FIG.
Cross-over loss in the 1,72 to 75 band is eliminated, and excellent broadband characteristics can be obtained.

In both of the above embodiments, the case where the frequency bands used by the antenna are continuous has been explained, but the interval between adjacent frequency bands used is within the crossover area of the multiplexer (usually 5% of the crossover frequency).
It is possible to apply the present invention as long as it is within the above range.

Further, the number of antennas is not limited to those in the above embodiments, and furthermore, the number of groupings is not limited.

Furthermore, the functions and effects of this invention are exactly the same for transmission and reception.

It goes without saying that various other modifications can be made without departing from the gist of the invention.

〔Effect of the invention〕

As detailed above, according to the present invention, it is possible to connect multiple antennas with consecutive frequency bands to the transmitter/receiver system without increasing loss at the crossover frequency, and it is possible to obtain excellent broadband characteristics. It is possible to provide a wideband antenna device.

[Brief explanation of drawings]

1 to 3 are block diagrams showing conventional wideband antenna devices, FIG. 4 is a diagram showing the frequency characteristics of FIG. 3, and FIG. 5 is a diagram showing an embodiment of the wideband antenna device according to the present invention. 6 is a diagram showing the frequency characteristics of FIG. 5, FIG. 7 is a diagram showing the configuration of another embodiment of the present invention, and FIG. 8 is a diagram showing the frequency characteristics of FIG. 7. 11, 12, 13, 71, 72-75... Antenna, 51, 53, 77, 80... Diplexer, 52, 78... Rotary joint, 7
6,79...Triplexer.

Claims (1)

[Claims] 1 At least 3 antennas installed on the same rotary table, where the interval between adjacent frequency bands is 5% or less of the center frequency of the interval, and N antennas whose frequency bands are not adjacent to each other. (N≧2) groups, a plurality of antennas among the grouped antennas are connected to each group, and the crossover frequency is set outside the frequency band used by each antenna in the group; a rotary joint having the same number of channels as the number of groups, and to which the common terminal of the first multiplexer or a single antenna among the grouped antennas is respectively connected to the channels on the rotating side; A wideband antenna device comprising a second multiplexer having a common terminal connected to a channel corresponding to the first multiplexer between a fixed side channel and a transmission/reception system.