CN2296101Y - Multichannel front signal emitter for quality TV pictures in rural areas - Google Patents

Abstract

The utility model relates to a transmitting apparatus of television signals, which is composed of an anti-interfere element attenuator 1, a driving amplifier 2, a linear power amplifier 3 and a power supply 4. The apparatus can receive the television signals sent from a far range, and the signals are sent out again for television reception in a close range. The method can save the service wire for cable televisions, can reduce construction cost and maintenance quantity, and can reach the effect of cable televisions.

Description

Farming district multichannel high quality television front end signal emitter

The utility model is a kind of electrical installation, promptly a kind of TV signal emitter that is applicable to the farming district.

TV has become the important daily necessities of vast urban and rural residents,, watch multiple programs, will see that particularly image quality than higher TV, then also will take certain measure.At present, can be cable TV for people provide the main method of multichannel high quality television.This method is also popularized in the cities and towns of relatively concentrating of living, away from the transmission of television facility, and also the farming district of living and relatively disperseing, comprising pastoral area, forest zone, mountain area, the enforcement of cable TV also exists many difficulties.Wherein mainly contain 2 points, the one, it is too high to set up the main line cost at a distance, and the 2nd, the coaxial cable expense in the village is too big.The MMDS system of Chu Xianing in recent years can solve the problem that agricultural district sets up main line at a distance with the microwave of 2.5～2.7GHZ the multi-channel TV signals long-distance transmissions.Distinguish when TV signal passes to farming, after receiving by low-converter is unified, also need with coaxial cable signal to be sent to every family, because sparsely populated in the village, the coaxial cable expense is still very high, has limited the development of agricultural district cable TV.

The purpose of this utility model is: develop and a kind ofly can cancel coaxial cable, can reach the effect of cable TV again, cheap transmission of television device.

Above-mentioned purpose is realized by following technical scheme: this device also is to be connected with the low-converter that receives the remote television signal, and different is: this emitter is connected with high-frequency linear power amplifier and power supply by the anti-interference element and forms.

Said anti-interference element can be the input port that is connected with low-converter.

Said anti-interference element can be that attenuator is connected with driving amplifier and constitutes.

Said high-frequency linear power amplifier can be the VSTSSPAOO852336 linear power amplifier.

The emitter that adopts such scheme to make, can be connected on the low-converter back, the TV signal that transmits at a distance, as signals such as MMDS, AML, reception is come, and launches again, supply closely television reception, like this, just can cancel user's coaxial cable, make the user still can watch the high-quality TV programme of many covers.In addition, this emitter, the TV signal that can also launch 1～1.2GHZ for the television reception of assembling frequency changer, can realize paid service so better, makes tv undertakings obtain certain compensation and develops.

Introduce a kind of embodiment below in conjunction with accompanying drawing:

Fig. 1 is the emitter structure chart of present embodiment.

Fig. 2 is the receiving system structure chart of present embodiment.

As shown in Figure 1, this emitter is by attenuator 1, driving amplifier 2, power amplifier 3, power supply 4 is formed, insert the input port of this device by MMDS low-converter output 1～1.2GHZ microwave signal, by the incoming level change emitter power output of 1C10 to 20db attenuator control emitter, carry out through the input of 1IC1 being input to the elementary of IT1 high frequency transformer by IC2 after the amplification of 30db gain, the high-frequency electrical of the secondary generation of IT1 flows through IC3 penetrates the space to being coupled to the transmitting antenna width of cloth by IC4 after the input of 1IC2 carries out power amplification that 36db gains.This machine adopts switch mode power+24V power supply, and the switch mode power operation principle no longer repeats.1IC1 can select CA9515 module amplifier for use, operating frequency 48-1200MHZ, Maximum Output Level 120dBuv, gain 30dB.1IC2 can select the VSTSSPA0085236 linear power amplifier for use, power output 36dBM, gain 36dB, output impedance 50.Transmitting antenna requires the above gain of 12dB, and bandwidth should reach more than the 120MHZ.

For the variation of temperature that conforms, this device can be set up temperature compensation network.In order to guarantee the matched well between driving amplifier and the power amplifier, can set up the impedance conversion net.

Because the wide-band microwave signal of 1～1.2GHZ of this emitter emission, general television set can't receive, so the user will be equipped with a frequency changer and just can receive.As shown in Figure 2, frequency changer by mixing 5, in put 6, local oscillator 7 three partial circuits form, the microwave signal of the 1～1.2GHZ that is received by antenna enters frequency mixer, local oscillation signal is also sent into frequency mixer simultaneously, and external signal frequency deducts the local oscillation signal frequency, and difference goes out a new IF-FRE, this frequency can be located in the uhf band, generally can send into the amplifier of 20dB gain at 470～566MHZ, the signal after the amplification just can be connected to the defeated wooden fork mouth of antenna of user's TV.This frequency changer adoptable integrated circuit is as UPC1687, IAM82008 etc., and local vibration source can adopt pressure oscillator, but stability is low.Because short distance reception, this frequency changer can be contained in indoor, and is more much lower than outdoor frequency converter requirement, thereby simple in structure, and cost is very low.In addition, local vibration source also can adopt crystal letter mode frequently, adopts this mode advantage a lot, good stability.Local frequency can be free according to the planning of locality.

If the signal of this emitter emission is located in the uhf band, then TV user is without frequency changer direct rating just, and this form is applicable to the user of collective of concentrated reception.

Claims (4)

1, multichannel high quality television front end signal emitter is distinguished in a kind of farming, also be to be connected with the low-converter that receives the remote television signal, it is characterized in that: this emitter is connected and forms with high-frequency linear power amplifier (3) and power supply (4) by the anti-interference element.

2, multichannel high quality television front end signal emitter is distinguished in farming according to claim 1, and it is characterized in that: said anti-interference element can be the input port that is connected with low-converter.

3, farming district according to claim 1 multichannel high quality television front end signal emitter is characterized in that: said anti-interference element can be that attenuator is connected with driving amplifier and constitutes.

4, multichannel high quality television front end signal emitter is distinguished in farming according to claim 1, and it is characterized in that: said high-frequency linear power amplifier can be the VSTSSPAOO852336 linear power amplifier.

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