Three-in-one tuner with compatibility of DVB-T/C and ATV

Abstract

The invention discloses a three-in-one tuner with the compatibility of DVB-T / C and ATV, comprising an input selection module, a selection control circuit, a radio-frequency gain adjustment module, a down-conversion module and a decoding demodulation module, wherein, the input selection module is used for selecting two groups of input signals of a ground signal and a wired signal; the selection control circuit is used for controlling the input selection module to carry out input selection on a radio-frequency signal; the radio-frequency gain adjustment module is used for controlling the gain of the radio-frequency signal; the down-conversion module is used for converting the received radio-frequency signal into an intermediate-frequency signal suitable for the decoding demodulation module;and the decoding demodulation module is used for decoding and demodulating the intermediate-frequency signal after being amplified. In the invention, two signal lines are connected to the two input ends of a high-frequency head, which one of the ground signal and the wired signal is input to a lower-level circuit by the input selection module, the invention has simple circuit formation structure,realizes the compatibility of the DVB-T / C and the ATV and has good performance and high sensitivity; and compared with the prior art, the invention has more convenient debugging and use.

Description

technical field [0001] The invention relates to a tuner, in particular to a three-in-one tuner compatible with DVB-T / C and ATV, wherein DVB-T refers to terrestrial digital television, DVB-C refers to cable digital television, and ATV refers to analog television. Background technique [0002] The basic function of the TV receiving system is to receive analog TV signals and digital TV signals (working frequency is 51MHZ-860MHZ). Separate channels, through frequency conversion and other processes, and then signal processing by the internal motherboard, and finally output analog audio / video signals for use, such as figure 1 and figure 2 As shown, in the prior art, the radio frequency part and the demodulation part of digital TV reception and analog TV reception are set separately, and in some cases, the radio frequency common decoding demodulation part of digital TV reception and analog TV reception is separated Setting, the circuit composition of existing tuner has the follo...

AI Technical Summary

Problems solved by technology

[0002] The basic function of the TV receiving system is to receive analog TV signals and digital TV signals (working frequency is 51MHZ-860MHZ). Separate channels, through frequency conversion and other processes, and then signal processing by the internal motherboard, and finally output analog audio / video signals for use, such as figure 1 and figure 2 As shown, in the prior art, the radio frequency part and the demodulation part of digital TV reception and analog TV reception are set separately, and in some cases, the radio frequency common decoding demodulation part of digital TV reception and analog TV reception is separated Setting, the circuit composition of existing tuner has the following defects: (1) because DVB-T and ATV circuit are difficult to be compatible, promptly add radio frequency low-noise amplifier module in the circuit that analog TV receives and strong signal can occur and can not satisfy the situation of customer , or remove the radio frequency low-noise amplifier module in the digital TV receiving circuit, there will be a phenomenon that the weak signal cannot reach the customer, making it difficult for the technical indicators to meet the specified requirements; (2) the circuit composition of the existing tuner is relatively complicated, so that the tuner Extremely inconvenient to debug and use

[0003] At present, there is no tuner capable of achieving DVB-T / C and ATV compatibility on the market

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