JPH04159824A - Antenna switching device for satellite - Google Patents

Abstract

PURPOSE:To eliminate the need for an exclusive switching signal, wiring, etc., so as to improve profitability by using a DC source for a converter as the switching signal of an RF switch also. CONSTITUTION:This device is provided with satellite antennas 1-3, converters 4-6, an RF switch 7, an RF switch control circuit 8, a low-pass filter 9, a power supply/signal terminal 10, and an RF switch box 11. The three antennas are used by switching them to another by means of a DC voltage supplied to the terminal 10. Therefore, the converters 4-6 can be used without problem and the profitability of the device can be improved, since the need for an exclusive switching signal, long cable wiring, etc., is eliminated and the DC voltage can be controlled within an allowable range of + or -10% against a standard voltage value.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention provides a plurality of satellite antennas that enable reception to be performed by switching to correspond to a plurality of reception conditions. The satellite antenna switching device switches the antenna by changing the voltage value of the DC voltage that is the power source of the frequency converter.

[Conventional technology]

Conventionally, when a plurality of satellite antennas are provided, the methods shown in FIGS. 2(A) and 2(B) have generally been used to switch the antennas. (^) is the case where an independent dedicated signal is used as the switching signal input to the RF switch control circuit 22 that switches the IIF switch 21, and (
B) is a method in which all the output signals of each converter are wired to the receiver body and switched within the receiver body. Furthermore, (A)
In this case, the RF switch box 25, which integrates a series of switching mechanism parts, is usually installed near the antenna installation location.

[Problem to be solved by the invention]

Therefore, in the case of (^), it is used for switching signal transmission.

In the case of (B), long cable wiring is required for each antenna between the converter and the receiver body, and dedicated switching signals are required for both.

The present invention uses DC voltage as a power source for a converter as a switching signal, eliminates the need for a dedicated switching signal, and switches antennas near the antenna installation location, thereby eliminating the need for long cable wiring as described above. The purpose of the present invention is to provide an antenna switching device for

[Means to solve the problem]

The present invention provides a plurality of satellite antennas that enable reception to be performed by switching to correspond to a plurality of reception conditions, and in which a DC power supply terminal to a frequency converter provided in the satellite antenna and a frequency A low-pass filter that allows only the DC power to pass through the power/signal terminal that also serves as the signal output terminal of the converter, and R based on the multiple voltage values from the DC power source obtained from the low-pass filter.
A satellite antenna switching device comprising an RF switch control circuit for switching the F switch, and an RF switch in which each fixed piece is coupled to the frequency converter of each satellite antenna and the movable piece is coupled to the power/signal terminal. It provides:

(Operation) The DC voltage used as a power supply for the converter provided in the satellite antenna usually has a tolerance of ±10% with respect to the standard voltage value, and as long as it is within this range, there is no problem in using the converter.

The present invention attempts to change the DC voltage value within such a range and switch the RF switch using this different voltage value.

〔Example〕

Hereinafter, a satellite antenna switching device according to the present invention will be explained based on the drawings. FIG. 1 is a block diagram of essential parts of an embodiment of a satellite antenna switching device according to the present invention.
In the figure, 1.2.3 is a satellite antenna, 4.5.6
is a converter for RWI to the satellite antenna, 7 is an RF
The RP switch switches to the antenna to be used according to the switch control circuit 8, and 8 is a low-pass filter (L
an RP switch control circuit that outputs a necessary switching signal to the RP switch 7 based on the signal from PF) 9;
9 is a low-pass filter (LPF) that allows only DC voltage to pass from the power/signal terminal IO; 10 is a power/signal terminal that serves both as a power supply to the converter and as a converter output via the RF switch 7; and 11 is the switching mechanism described above. This is an RF switch box with integrated parts.

Next, the operation of the present invention will be explained. Since the standard DC voltage value of the converter is generally 15 m, it is set to 15 (V) in this embodiment as well.

And the range is ±10% for 15(V), that is, 13.
The converter operates normally without any problems within the range of 5 (V) to 16.5 m. In this example, three antennas are switched and used as shown in Fig. 1, so the power supply/signal Three types of DC voltage are set within the above range as the DC voltage supplied to the terminal 10. For example, 14 (V), 15 (
V), 16 (V), and the power supply/signal terminal 10 receives the DC voltage as well as the converter output as described above.
F signal is superimposed. The LPF 9 cuts off the RF signal and outputs only the DC voltage to the RF switch control circuit 8. RF switch control circuit 8 is LPF9
For example, the movable piece 7 of the RF switch 7 switches the RF switch 7 to a predetermined position set at the design stage depending on whether the DC voltage is 14 m, 15 m, or 16 (V). However, when the DC voltage of the power/signal terminal IO is 14 m, the fixed piece 7□
When it is 15 (V), it is switched to the fixed piece 73, and when it is 16 m, it is switched to the fixed piece 7. Therefore, in this example, when the DC voltage is 14 (V), the antenna L is switched and the converter 4 is switched to the DC voltage 14 m.
It operates normally, converts the signal received by the antenna to a predetermined frequency, and outputs the signal to the power/signal terminal 10 via the RF switch 7.

〔Effect of the invention〕

As explained above, according to the present invention, where a dedicated switching signal and a long wiring for sending the signal to the RF switch are required when switching between multiple satellite antennas, the converter By using the DC power source as a switching signal for the RF switch, the dedicated switching signal and wiring are no longer necessary, and this has a great economical advantage.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a main part of an embodiment of a satellite antenna switching device according to the present invention, and FIG. 2 is a block diagram of a main part of a conventional satellite antenna switching device. In the figure, 1.2.3 is a satellite antenna, 4.5.6 is a converter, 7.21.26 is an RF switch, and 8.22 is R
F switch control circuit, 9 is a low pass filter (
LPF), 10.23.28 is IT source/signal terminal, 11
．． 25 is an RF switch box, 24 and 27 are switching signals, and 29 is a satellite broadcasting receiver body. Patent applicant: Fujitsu General Ltd. Figure 1 Figure 2

Claims (1)

[Claims] A DC power supply terminal to a frequency converter provided in the satellite antenna and a signal output of the frequency converter in a device that is equipped with multiple satellite antennas and can receive signals by switching to correspond to multiple reception conditions. A low-pass filter that passes only the DC power source through a current/signal terminal that also serves as a terminal, and an RF switch that switches the RF switch based on a plurality of voltage values from the DC power source obtained from the low-pass filter. a control circuit;
Each fixed piece is coupled to the frequency converter of each satellite antenna, and the movable piece is coupled to the power/signal terminal.
A satellite antenna switching device characterized by comprising an F switch.