JPH04334131A - Three-face antenna space diversity receiver - Google Patents

Abstract

PURPOSE:To reduce number of endless phase shifters and phase shifter control circuits and to decrease power consumption inexpensively. CONSTITUTION:Level detectors 11a, 11b detect a reception level of reception signals S12, S13. Changeover device control circuit 12 compares results of detection of level detectors 11a, 11b and outputs a selection control signal. A changeover device 13 selects any of reception signals S12, S13 which has a higher reception level based on the selection control signal and outputs the selected output. A reception signal S11 and an output signal of the changeover device 13 are synthesized in phase by a phase shifter control circuit 14, an endless phase shifter 15, power distributers 16a, 16b and a power synthesizer 17 to output a transmission signal 18.

Description

[Detailed description of the invention]

0001

FIELD OF INDUSTRIAL APPLICATION The present invention is applied to a three-sided antenna space diversity receiving device for a microwave receiving device using a satellite communication system.

0002

2. Description of the Related Art FIG. 4 is a block diagram of a conventional three-sided antenna space diversity receiving apparatus.

Conventionally, as shown in FIG. 4, a three-sided antenna space diversity receiving apparatus includes a power divider 46a that branches a received signal S11, an infinite phase shifter 45 that varies the phase of a received signal S12, and an infinite phase shifter 46a that branches a received signal S11. A power divider 46b that branches the output signal of the phase box 45, and power dividers 46a and 46b.
A phase shifter control circuit 44 that compares the phases of one of the output signals of the two output signals and controls an infinite phase shifter 45 so that the received signal S11 and the received signal S12 are in phase, and power dividers 46a and 46b.
a power combiner 47 that combines the other output of the power combiner 47, an infinite phase shifter 15 that similarly in-phase combines the output signal of the power combiner 47 and the received signal S13, a phase shifter control circuit 14, and a divider 1.
6a, 16b, and a power combiner 17.

0004

[Problem to be Solved by the Invention] However, such a conventional three-sided antenna space diversity receiver has two infinite phase shifters in order to combine all three received signals in phase. Another drawback is that the circuit configuration is more complex than the space diversity method using a normal two-sided antenna. Also, if the control speeds of these two phase shifters are the same, in-phase synthesis may not be possible, so the control speeds of the two phase shifters must be different, and this control speed must be modulated. The drawback was that it was difficult to determine because it depended on the method. Furthermore, in terms of noise figure, the three-sided antenna had the disadvantage that it was worse than normal space diversity.

The present invention solves the above-mentioned drawbacks, and provides a three-plane antenna space diversity receiver that can reduce the number of infinite phase shifters and phase shifter control circuits, is inexpensive, and has low power consumption. The purpose is to provide.

[0006]

[Means for Solving the Problems] The present invention provides a three-sided antenna space diversity receiver equipped with a combining means for in-phase combining one of three input received signals and an input signal. A level detector that detects the reception levels of the remaining two of the three reception signals, a switch control circuit that compares the detection results of the level detector and generates a selection control signal, and The present invention is characterized by comprising a switch that selects the higher received level of the remaining two received signals based on the control signal and supplies it as the input signal.

Further, in the present invention, the combining means includes a first power divider that branches one of the received signal and the output signal of the switch into two, and an infinite phase shifter that controls the phase of the other of the one received signal and the output signal of the switching device to be in phase with the one signal based on a control signal; a second power divider that branches an output signal into two; a power combiner that combines one output signal of the first power divider and one output signal of the second power divider; The phase shifter control circuit may include a phase shifter control circuit that compares the phases of the other output signal of the first power divider and the other output signal of the second power divider to generate and provide the phase control signal. can.

[0008]

[Operation] The combining means performs in-phase combining of one of the three received signals and the input signal. The level detector detects the reception levels of the remaining two of the three reception signals. The switch control circuit compares the detection results of the level detectors and generates a selection control signal. Based on this selection control signal, the switch selects the one with a higher reception level of the remaining two received signals and supplies it to the combining means as the input signal.

As described above, the number of infinite phase shifters and phase shifter control circuits can be reduced, and the cost and power consumption can also be reduced.

0010

Embodiments Examples of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a three-sided antenna space diversity receiver according to an embodiment of the present invention. FIG. 2 is a block diagram of the level detector, level detector control circuit, and switch of the three-sided antenna space diversity receiving apparatus of the present invention.

In FIGS. 1 and 2, the three-sided antenna space diversity receiving device performs in-phase synthesis of the received signal S11 and the input signal as one of the three input received signals S11 to S13. Have the means.

Here, the present invention is characterized by level detectors 11a and 11b which respectively detect the reception levels of the reception signals S12 and S13 as the remaining two reception signals of the three reception signals S11 to S13. , a switch control circuit 12 that compares the detection results of the level detectors 11a and 11b and generates a selection control signal, and selects the higher reception level of the reception signals S12 and S13 based on this selection control signal, and The present invention also includes a switch 13 which supplies the input signal to the synthesizing means.

The combining means also includes a power divider 16 as a first power divider that branches the received signal S11 into two.
a, an infinite phase shifter 15 that controls the phase of the output signal of the switch 13 to be in phase with the received signal S11 based on the input phase control signal, and the output signal of this infinite phase shifter 15 is divided into two. Power divider 16 as a second power divider to branch
b, a power combiner 17 that combines one output signal of the power divider 16a and one output signal of the power divider 16b and outputs the transmission signal 18, and a power combiner 17 that combines one output signal of the power divider 16a and one output signal of the power divider 16b and outputs the transmission signal 18, and the other output signal of the power divider 16a and the power It includes a phase shifter control circuit 14 that compares the phase with the other output signal of the distributor 16b, generates the phase control signal, and supplies it to the infinite phase shifter 15.

Further, the level detectors 11a and 11b include automatic gain amplifiers 21a and 21b and automatic gain amplifiers 21a and 21b, respectively, which input received signals S12 and S13.
The switch control circuit 12 compares the output automatic gain control voltages of the automatic gain amplifier control circuits 22a and 22b and determines the reception level of the reception signals S12 and S13. Delay circuits 24a, 24b that delay the output signals of the discriminators 23a, 23b; and reception signals S12, 24b based on the output signals of the delay circuits 24a, 24b;
Turn on the higher reception level of S13, and turn on the lower one.
The switch 13 includes a diode switch 26a that outputs the higher reception level of the received signals S12 and S13 and turns off the lower received signal based on the output signals of the switch circuits 25a and 25b; 26b
and a power combiner 27 that combines the output signals of the diode switches 26a and 26b and outputs the result to the infinite phase shifter 15.

The operation of the three-sided antenna space diversity receiving apparatus having such a configuration will be explained. FIG. 3 is a diagram showing the switching operation of the switching device of the three-sided antenna space diversity receiving device of the present invention. Level detector 11
a and 11b detect the reception levels of the reception signals S12 and S13. The automatic gain amplifiers 21a and 21b are for stably detecting the received signal level, and their gains are varied by automatic gain control voltages output from the automatic gain amplifier control circuits 22a and 22b.

The switch control circuit 12 includes a level detector 11
By comparing the automatic gain control voltages outputted from a and 11b, the discriminators 23a and 23b identify which of the received signals S12 and S13 has a higher level. For example, when the level of the received signal S12 is high, the discriminator 23a operates to turn on the switch circuit 25a composed of a transistor or the like. On the contrary, discriminator 2
3b operates to turn off the switch circuit 25b.

The switch 13 cuts off the received signal when the output signal of the switch control circuit 12 is "off". That is, the lower level side of the received signals S12 and S13 is cut off, and only the higher level side is output.

"ON" of the switch circuits 25a and 25b;
"Off" operation is when one side changes from "on" to "off",
Delay circuits 24a and 24b are provided so that the other switch changes from "off" to "on" after the received signal is sufficiently attenuated by the diode switches 26a, 26b. FIG. 3 shows the output level of the power combiner 27 at the time of switching. At time t1, the diode switch 26a turns off, and the received signal S
At time t2 when 12 has sufficiently attenuated, the diode switch 26
b is turned on.

The received signal S11 and the received signal S12 or S13 selected by the switch 13 are phase-compared by a phase comparator in the phase shifter control circuit 14, and the infinite phase shifter 15 compares the phases of the received signal S12 or S13 selected by the switch 13. The received signal S12 or the received signal S13 is controlled so that they are in phase, and the power combiner 17 combines the two signals.

[0020]

As described above, the present invention has the excellent effect of being able to reduce the number of infinite phase shifters and phase shifter control circuits, being inexpensive, and reducing power consumption.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a three-sided antenna space diversity receiving apparatus according to an embodiment of the present invention.

FIG. 2 is a block configuration diagram of a level detector, a switching control circuit, and a switching device according to the present invention.

FIG. 3 is a diagram showing the switching operation of the switch of the three-sided antenna space diversity receiving device of the present invention.

FIG. 4 is a block diagram of a conventional three-sided antenna space diversity receiving device.

[Explanation of symbols]

11a, 11b Level detector 12 Switch control circuit 13 Switch 14, 44 Phase shifter control circuit 15, 45 Infinite phase shifter 16a, 16b, 46a-46b Power divider 17,
27, 47 Power combiner 18, 48 Transmission signal 21a, 21b Automatic gain amplifier 22a, 22b Automatic gain amplifier control circuit (AGC amplifier control circuit) 23a, 23b Discriminator 24a, 24b Delay circuit 25a, 25b Switch circuit 26a, 26b Diode Switches S11 to S13
Received signal t1, t2 time

Claims (2)

[Claims] Claim 1. A three-sided antenna space diversity receiving device comprising a combining means for in-phase combining one received signal among the three input received signals and an input signal input, wherein one of the three received signals a level detector that detects the reception levels of the remaining two reception signals, respectively;
A switch control circuit that compares the detection results of the level detector and generates a selection control signal, and a switch control circuit that selects the higher received level of the remaining two received signals based on this selection control signal and selects the input signal. A three-sided antenna space diversity receiving device, characterized in that it is equipped with a switch that provides a three-sided antenna space diversity receiving device. 2. The combining means includes a first power divider that branches one of the one received signal and the output signal of the switching device into two, and a first power divider that splits one of the received signals and the output signal of the switching device into two, and an infinite phase shifter that controls the phase of the other of the one received signal and the output signal of the switch so that it is in phase with the one signal; a second power divider that branches into two power dividers; a power combiner that combines one output signal of the first power divider and one output signal of the second power divider; 3. A phase shifter control circuit according to claim 1, further comprising a phase shifter control circuit that compares the phases of the other output signal of the power divider and the other output signal of the second power divider to generate and provide the phase control signal. Surface antenna space diversity receiver.