JPH0265420A - diversity receiver - Google Patents

Abstract

PURPOSE:To reduce the number of coaxial cables and to prevent the occurrence of heat crosstalk by providing plural antennas and a switching means in diversity operation in one case and using a local oscillation frequency signal to the antennas in common. CONSTITUTION:The antennas 4, 5 and a diversity switching means in diversity operation are provided in one case 22. Since a conversion signal with stronger signal intensity of antenna input terminals 6, 7 is outputted to a receiver output terminal 21, the diversity effect is obtained by the connection of one coaxial cable 3 only. A local oscillation frequency signal outputted from a local oscillation section 12 by the control of a local oscillation crystal 13 is distributed to mixers 10, 11 by a distribution section 14 and used in common. Thus, the number of coaxial cables connecting the receiver main body is reduced and no beat crosstalk takes place.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention is suitable for receiving radio waves from a transmitter, and is particularly suitable for receiving radio waves from a wireless microphone device used in broadcasting stations, halls, theaters, schools, etc. Regarding diversity receivers.

Prior Art FIG. 5 shows a conventional diversity receiver. In FIG. 5, 51/I'i receiver body, 52.53 are diversity antenna devices, and 54.55 are receiver body 51 and diversity antenna device 5, respectively.
This is a coaxial cable that connects 2.53.

FIGS. 6(a) and 6(b) respectively show the configuration of the diversity antenna devices 52 and 53 using converters. FIG. 6 (in 31, 56 is an antenna,
57 is an antenna input terminal, 58 is an antenna input terminal 57
59 is a mixer part for converting the high frequency signal amplified by the RF amplification part 58 to an intermediate frequency; 60 is a mixer part 59 that applies a local oscillation frequency signal to the mixer part 59; A local oscillation unit, 61 is a local oscillation crystal that controls the local oscillation unit 60, 62 is a mixer part 5
The IFF width section 63 amplifies the intermediate frequency received signal converted in step 9, and the receiver output terminal 63 sends the IF multiplied signal to the receiver main body 5E via the coaxial cable 54. Each of these members is provided in a case 64. As shown in FIG. 6 (bl), the other diversity antenna device 53 also has an antenna 65, an antenna input terminal 66, a part of the RF amplification unit 7 mixer 68,
Local oscillation section 69, local oscillation crystal 70, IF amplification section 71
, a receiver output terminal 72, and a case 73 including these parts.

Next, the operation of the above conventional example will be explained.

Radio waves from a transmitter (not shown) are received by antennas 56, 65 of diversity antenna devices 52, 53, and the high frequency signals are sent to antenna input terminals 57, 66 and I.
I) The signal is sent to the RF amplification section 58, 67 and amplified.

This amplified high frequency signal is converted into an intermediate frequency with less cable loss by the mixer section 59.68 and the local oscillation frequency signal applied from the local oscillation section 60.69.
This intermediate frequency signal is amplified by an IF amplifier 6271 and sent to receiver output terminals 63 and 72, and then sent to the receiver main body 51 via coaxial cables 54 and 55, respectively. In the receiver body 51, reception is performed by switching to one of the antenna systems with a stronger signal.

In this way, even in the conventional diversity receiver described above, diversity reception without dead points can be achieved by using the same number of coaxial cables 54.55 as the antennas 56.65 and by making the local oscillation frequencies of the multiple antenna converters the same. It can be performed.

Problems to be Solved by the Invention However, in the above-mentioned conventional diversity receiver,
Since as many coaxial cables as there are antennas are required, not only does construction take a lot of time, but the overall cost including construction cannot be reduced. In addition, even the smallest system using two antennas requires two coaxial cables, and in antenna devices that use converters, in order to avoid beat interference between the two antenna converters, the local oscillation frequency must be the same, or each There were issues such as the need to select a local oscillation frequency and intermediate frequency that would not cause beat interference in the antenna section.

The present invention solves these conventional problems, and makes it possible to reduce the number of coaxial cables, shorten working time, and reduce the overall cost including construction. The object of the present invention is to provide a diversity receiver that uses a common local oscillation frequency to make the intermediate frequencies the same and to reduce the occurrence of beat interference. It is something.

Means for Solving the Problems In order to achieve the above object, the present invention provides a diversity antenna device including a plurality of antennas that perform diversity operation and a diversity switching means for the plurality of antennas in one case, and the diversity antenna. It has a receiver main body to which the switching means of the device is connected via one coaxial cable.

Further, the diversity antenna device is provided with local oscillation means for outputting a common local oscillation frequency signal for converting high frequency signals received by each antenna of the diversity antenna device into an intermediate frequency. Alternatively, the receiver main body side is provided with local oscillation means for outputting a common local oscillation frequency signal for converting high frequency signals received by each antenna of the diversity antenna device into an intermediate frequency.

The local oscillation frequency output from the local oscillation means is preferably set low, and the diversity antenna device preferably includes a multiplier for multiplying the local oscillation frequency, and the diversity antenna device can use a plurality of multipliers.

Effects The present invention has the following effects due to the above structure.

The number of coaxial cables connected to the receiver body can be reduced by configuring an integrated diper/tee antenna device by providing a plurality of antennas that perform diversity operation and their switching means in one case.

Furthermore, by using a common local oscillation frequency for each antenna, it is possible to make the intermediate frequency of each antenna the same.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to the drawings.

First, a first embodiment of the present invention will be described.

1 and 2 show a diversity receiver according to a first embodiment of the present invention, FIG. 1 is a schematic diagram of the overall configuration, and FIG. 2 is a schematic block diagram of a diversity antenna device.

In FIG. 1, 1 is a receiver main body, 2 is a diversity antenna device, and 3 is a coaxial cable connecting the receiver main body 1 and the diper/tee antenna device 2.

In Fig. 2, 4 and 5 are antennas that perform diversity operation, 6 and 7 are antenna input terminals, 8 and 9 are RF amplifiers that are connected to the antenna input terminals 6 and 7 and amplify high frequency signals, and 10 and 11 are RF Part 12 of a mixer for converting the high frequency signal amplified by the amplifiers 8 and 9 to an intermediate frequency
13 is a local oscillation crystal that controls the local oscillation unit 12; 14 is a local oscillation distribution unit that distributes the output of the local oscillation unit 12 to the mixer parts 10 and 11; 15; and 16 are mixer parts 10 and 11 that amplify the intermediate frequency received signal converted by the IF amplification section; 17;
and 18 are DC converters that convert the IF multiplied signals amplified by the IF amplifiers 15 and 16 into a DC voltage proportional to the voltage;
19 is a voltage comparator that converts the DC voltage converted by the DC converters 17 and 18; 20 is an output switching unit that outputs either one of the IF multiplied signals amplified by the IF amplifiers 15 and 16 under the control of the voltage comparator 19; , 21 are receiver output terminals for sending the IF multiplied signal outputted from the output switching section 20 to the receiver main body 1 via the coaxial cable 3. Each of the above-mentioned members Fi is provided in one case 22 (see FIG. 1).

The operation of the above configuration will be explained below.

Radio waves from a transmitter (not shown) are received by each antenna 4 and 5, and the high frequency signal is sent to each antenna input terminal 6.
and 7, the signal is sent to each RF amplifying section 8 and 9 and amplified. This amplified high frequency signal is outputted from the local oscillation section 12 by each mixer section 10 and 11, and is converted into an intermediate frequency with less coaxial cable loss by the local oscillation frequency signal distributed by the local oscillation distribution section 14. , this intermediate frequency signal is amplified by each 1F amplifier section I5 and 16. Each DC
The conversion parts I7 and 18 convert the voltage into a DC voltage proportional to the IF voltage, each voltage is compared by the voltage comparison part I9, and the comparison output controls the output switching part 20, and the signals of each system are sent to the receiver output terminal 21. Outputs a signal IF times the stronger one. Therefore, the IF multiplied signal can be sent to the receiver body 1 via the coaxial cable 3. In this embodiment, for example, the signals received by antennas 4 and 5 are 800MHz.
If the local oscillation frequency is approximately 550MHz
and set the IF multiplied signal to approximately 250 MHz.

As described above, according to the above embodiment, by providing the antennas 4 and 5 that operate in diversity and the diversity switching means in one case 22, the converted signal of the stronger signal strength of each antenna input terminal 6 and 7 is received. Since it can be output to the machine output terminal 21, it has the advantage that a diversity effect can be obtained by connecting only one coaxial cable 3. Further, according to the above embodiment, the local oscillation frequency signal output from the local oscillation section 12 is distributed to the remixers 10 and 11 by the distribution section 14 under the control of the local oscillation crystal 13, so that they are commonly used. , the intermediate frequencies of the antennas 4.5 can be made the same, and there is an advantage that beat interference does not occur.

Next, a second embodiment of the present invention will be described.

3 and 4 show a diversity receiver according to a second embodiment of the present invention, FIG. 3 is a schematic diagram of the overall configuration, and FIG. 4 is a schematic block diagram of a diversity antenna device.

As is clear from FIGS. 3 and 4, this embodiment has a plurality of diversity antenna devices 2 each connected to the receiver main body 1 with one coaxial cable 3, and is different from the first embodiment described above. Identical parts will be designated by the same reference numerals and their explanations will be omitted, and different configurations will be explained.

In this embodiment, the local oscillation frequency is output on the receiver main body 1 side. That is, on the receiver main body 1 side, the local oscillation section 24 outputs a low local oscillation frequency signal under the control of the local oscillation crystal 23, and this local oscillation frequency signal is distributed by the local oscillation distribution section 25 to the diversity antenna device 20. It passes through the corresponding number of low-pass filters 26, and is sent to each diversity antenna device 2 via each coaxial cable 3. On each diversity antenna device 2 side, the local oscillation frequency signal is passed through a low-pass filter 27, converted to a higher frequency by a multiplier 28, and then converted to a common local oscillation frequency by a local oscillation distribution unit 14 and sent to each mixer part 10 and 11. distribute. on the other hand,
The IF multiplied signal output from the output switching section 20 of the diversity antenna device 2 is passed through the no-bus filter 29, passed through the bypass filter 30 of the receiver main body 1 via the coaxial cable 3, and sent to the high frequency amplification section 31. .

As in this embodiment, a local oscillation section 24, a local oscillation crystal 23
, by providing the local oscillation distribution section 25 and the like on the receiver main body 1 side, and distributing the local oscillation frequency signal on the receiver main body 1 side so that it is commonly used for the antennas 4 and 5 of each diversity antenna device 2. , the occurrence of beat interference can be prevented by simply making the intermediate frequencies of each antenna the same. Note that even when one diversity antenna device 2 is used as in the first embodiment, the same configuration as this embodiment is possible.

In addition, as in this embodiment, by transmitting at a local oscillation frequency lower than that on the receiver main body 1 side and converting it to a higher local oscillating frequency by the multiplier 28 on the diversity antenna device 2 side, the filter on the receiver main body 1 side It can be separated easily and coaxial cable loss can be reduced.

For example, the signals received by antennas 4 and 5 are 800
If it is the MHz band, the local oscillation frequency sent from the receiver main body 1 side is converted to 40 to 5QMHz by the multiplier 28 on the diversity antenna device 2 side, and the mixer part t
The local oscillation frequency applied to o and ii is approximately 550 MHz.
and set the IF multiplied signal to approximately 250 MHz.

In particular, when a plurality of diversity antenna devices 2 are used as in this embodiment, a multi-antenna diversity receiver can be configured with half the number of coaxial cables 3 as antennas, and therefore the time required for construction can be shortened. It is clear that the cost of the entire system including installation work cost can be reduced.

Effects of the Invention As described above, according to the present invention, a plurality of antennas that perform diversity operation and their switching means are provided in one case to constitute an integrated diversity antenna device, so that it can be easily connected to the receiver body. The number of coaxial cables to be installed can be reduced, and therefore the time required for construction can be shortened, and installation construction costs and overall costs can be lowered.

Furthermore, since the local oscillation frequency signal is commonly used for the antennas, it is possible to make the intermediate frequency of each antenna the same, and it is possible to prevent beat interference from occurring.

Then, by distributing and transmitting the local oscillation frequency signal from the receiver itself, the intermediate frequency of each antenna can be easily made the same, thereby preventing beat interference, especially when multiple diversity antenna devices are used. In addition, by transmitting at a local oscillation frequency lower than that on the receiver side and converting it to a higher local oscillation frequency on the diversity antenna device side, it is easier to separate with a filter and reduce coaxial cable loss. .

[Brief explanation of the drawing]

1 and 2 show a diversity receiver according to a first embodiment of the present invention, FIG. 1 is a schematic diagram of the overall configuration, FIG. 2 is a schematic block diagram of a diversity antenna device, and FIG. 4 shows a diversity receiver according to a second embodiment of the present invention, FIG. 3 is an overall schematic block diagram, FIG. 4 is a schematic block diagram of a diversity antenna device, and FIGS. 5 and 6 are A conventional divertee receiver is shown, FIG. 5 is a schematic diagram of the overall configuration, and FIG. 6 (al.
(bl is a schematic block diagram of the diversity antenna device, respectively. 1... Receiver body, 2... Diversity antenna device, 3... Coaxial cable, 4, 5... Antenna,
6゜7...Antenna input terminal, 8.9...RF amplification section, 10゜11...Part of mixer, 12...Local oscillation section, 13...Crystal for local oscillation, 14... -Local oscillation distribution section, 15. 1.6...IF amplification section, 17.18.
...DC conversion unit, 19...Voltage comparison unit, 20...Output switching unit, 21...Receiver output terminal, 22...Case, 23...Crystal for local oscillation, 24... Local oscillation section, 25...Local oscillation distribution section, 26.27.Low pass filter, 28..FA section, 29.30.Bypass filter.

Claims (5)

[Claims] (1) A diversity antenna device that includes multiple antennas that perform diversity operation and diversity switching means for these multiple antennas in one case, and a receiver body that connects the switching means of this diversity antenna device with a single coaxial cable. Diversity receiver with. (2) The diversity receiver according to claim 1, wherein the diversity antenna device includes local oscillation means for outputting a common local oscillation frequency signal for converting high frequency signals received by each antenna of the diversity antenna device into an intermediate frequency. . (3) The diversity receiver according to claim 1, further comprising local oscillation means for outputting a common local oscillation frequency signal for converting high frequency signals received by each antenna of the diversity antenna device into an intermediate frequency, on the receiver main body side. . (4) The diversity receiver according to claim 3, further comprising a multiplication means for setting a low local oscillation frequency output from the local oscillation means and multiplying this local oscillation frequency on the diversity antenna device side. (5) The diversity receiver according to claim 3 or 4, which uses a plurality of diversity antenna devices.