TWI395479B - Tuner - Google Patents

Description

Tuner

The present invention relates to a tuner, and more particularly to a tuner that can support the receiving operation of digital television and analog television signals.

With the advancement of communication technology and compression technology, global television broadcasting has gradually been replaced by digital television broadcasting from analog television broadcasting. The revolution in digital broadcasting will drive the rapid development of related industries. Digital TV and Set-Top-Box (STB) are one of them. In the prior art, the program supply system provider uses the head end device to transmit the digital television signal to the user end, and the user terminal can use the digital television, the set-top box, or other digital receiving system supporting the playing standard to make the received signal into various digits. After processing, a television program or video multimedia is presented. In the receiver, the tuner is mainly used for signal transmission.

Generally, a tuner is used to amplify and down-convert a received radio frequency (Radio Frequency) signal to an intermediate frequency (Intermediate Frequency) range. After that, it is converted by a digital to analog converter (Analog to Digital Converter), and then demodulated by the demodulator. However, with the rapid development of technology, how to design a tuning device that can effectively have more additional functions is one of the direction that the industry is constantly striving for.

The invention relates to a Tuner, which can support the receiving operation of a digital television signal and an analog television signal. Thus, compared with the conventional tuner, the tuner related to the present invention can effectively support the reception of digital and analog television signals, and has the advantages of wide application and high added value.

According to an aspect of the present invention, an adjustment device is provided, which can support the receiving operation of a digital television signal and an analog television signal. The tuning device includes a Low Noise Amplifier, a Quadrature Mixer, a Channel Filter, an up-conversion module, and a switching circuit. The low noise amplifier is used to receive the input RF signal and provide the processed RF signal. The quadrature mixer is configured to receive and down-convert the processed RF signal to generate a Low Intermediate Frequency (Low IF) signal. The channel filter is configured to filter the low intermediate frequency signal to generate the first signal, and the first signal corresponds to the signal frequency band of the digital television. The up-converter module is configured to up-convert the low-IF signal to generate a second signal, and the second signal corresponds to a signal band of the analog television. The switching circuit is controlled by the selection signal to selectively enable one of the channel filter and the up-conversion module to selectively provide one of the first and second signals.

In order to make the above-mentioned contents of the present invention more comprehensible, a preferred embodiment will be described below, and in conjunction with the drawings, a detailed description is as follows:

Please refer to FIG. 1 , which is a block diagram of a tuner in accordance with an embodiment of the present invention. The Tuner 1 is applied to a television signal receiver (not shown) for receiving television signals. The television signal receiver includes, for example, an antenna module 2 for receiving an RF signal SRF and correspondingly providing an input RF signal SRF_i. For example, the antenna module 2 includes an antenna Ant and a filter Flt.

The tuner 1 can support, for example, a digital television signal and an analog television signal receiving operation. The tuner 1 includes a Low Noise Amplifier 10, a Quadrature Mixer 12, a channel filter 14, an up-conversion module 16, and a switching circuit 18. The low noise amplifier 10 is configured to receive the input RF signal SRF_i provided by the antenna module 2 and provide a processed RF signal. For example, the processed RF signal is transmitted in a differential manner, including the signal portion SRF_o ⁺ and the signal portion SRF_o ^- .

The quadrature mixer 12 is configured to receive and perform a down conversion of the processed RF signals SRF_o ⁺ and SRF_o ^- to generate a Low Intermediate Frequency signal. For example, the quadrature mixer 12 includes a signal converter 120, a complex mixer 122, and an intermediate frequency poly-phase filter 126, as shown in FIG.

The signal converter 120 is configured to convert the processed RF signals SRF_o ⁺ and SRF_o ^- to generate corresponding RF complex signals, wherein the RF complex signals include signal portions SRF_I ⁺ , SRF_I ^- , SRF_Q ⁺ and SRF_Q ^- . The signal parts SRF_I ⁺ and SRF_I ^- are real component signals, and SRF_Q ⁺ and SRF_Q ^- are imaginary component signals.

The complex frequency mixer 122 is implemented, for example, by four multipliers for mixing orthogonal signals and RF complex signals (including signal portions SRF_I ⁺ , SRF_I ^- , SRF_Q ^{+ ,} and SRF_Q ^- ) to Generate low IF quadrature signals. For example, the orthogonal signal includes signal portions SOL_I ⁺ , SOL_I ^- , SOL_Q ^{+ ,} and SOL_Q ^- . The quadrature mixer 12 further includes, for example, an oscillator 128 and a frequency divider 126. The orthogonal signal is obtained by, for example, a frequency divider 126, and the oscillation signal provided by the oscillator 128 is divided by two frequencies. The oscillating signal includes, for example, the signal portions SOL ⁺ and SOL ^- .

The intermediate frequency polyphase filter 124 is configured to suppress a negative frequency in the low intermediate frequency orthogonal signal (the output of the complex frequency mixer 122) to eliminate the virtual frequency in the low intermediate frequency orthogonal signal to generate Low IF signal. For example, the low IF signal includes the signal parts SIF ⁺ and SIF ^- .

The channel filter 14 is configured to perform a filtering operation on the low intermediate frequency signal to generate the first signal S1. For example, the frequency of the first signal S1 is close to 5 megahertz (Mega Hertz, MHz), which corresponds to the signal band of the digital television. The modulator 1 further includes, for example, a gain programmable amplifier (Programmable Gain Amplifier) 20 for amplifying the first signal S1 provided by the channel filter 14 and providing the generated signal to the associated digital television signal processing unit.

The up-converting module 16 is configured to perform an up-conversion operation on the low-IF signal to generate a second signal S2. The frequency of the second signal S2 corresponds to, for example, a signal band of the analog television, for example, 36 MHz. For example, the up-conversion module 16 includes a filter 160, an up mixer 162, a frequency divider 166, and an oscillator 168, as shown in FIG.

The filter 160 includes filter units 160a and 160b for filtering the second harmonic component and the third harmonic component of the low intermediate frequency signal to generate the filtered low intermediate frequency signal. The up-converter 162 is implemented, for example, by two multipliers for mixing the reference signal and the filtered IF signal to generate the second signal S2. For example, the up-conversion module 16 further includes an oscillator 168 and a frequency divider 166. The reference signal is obtained by, for example, the frequency divider 166, and the oscillation signal provided by the oscillator 168 is divided.

For example, the up-converter module 16 further includes a driver amplifier 164 for amplifying the second signal S2 generated by the up-converter mixer 162 and outputting the amplified second signal S2.

The switching circuit 18 is coupled to the quadrature mixer 12, the channel filter 14, and the upscaling module 16. The switching circuit 18 is selectively enabled by the selection signal Ss1 to selectively enable one of the channel filter 14 and the up-conversion module 16 to selectively provide one of the first and second signals S1 and S2. For example, switching circuit 18 selectively provides low IF signals to one of channel filter 14 and upscaling module 16, for example, to selectively enable its operation. In another example, the switching circuit 18 selectively activates the channel filter 14 and the up-converting module 16 by selectively enabling the power path of the channel filter 14 and the power supply path of the up-converting module 16. One of the operations.

The tuners of the embodiments of the present invention are provided with circuits for supporting the digital television signal frequency band and the analog television frequency band signal operation, and can support the receiving operation of the digital television signal and the analog television signal. Thus, compared with the conventional tuner, the tuner related to the present invention can effectively support the reception of digital and analog television signals, and has the advantages of wide application and high added value.

In view of the above, the present invention has been disclosed in a preferred embodiment, and is not intended to limit the present invention. A person skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

1. . . Frequency modulator

12. . . Orthogonal mixer

14. . . Channel filter

16. . . Upsampling module

18. . . Switching circuit

20,164. . . Drive amplifier

2. . . Antenna module

Ant. . . antenna

Flt, 160. . . filter

120. . . Signal converter

122. . . Multi-frequency mixer

124. . . IF multiphase filter

126, 166. . . Frequency divider

128,168. . . Oscillator

162. . . Up-conversion mixer

160a, 160b. . . Filter unit

FIG. 1 is a block diagram of a tuner of an embodiment of the present invention.

Fig. 2 is a detailed block diagram of the orthogonal mixer 12 in Fig. 1.

Figure 3 is a detailed block diagram of the up-converter module in Figure 1.

1. . . Frequency modulator

12. . . Orthogonal mixer

14. . . Channel filter

16. . . Upsampling module

18. . . Switching circuit

20. . . Drive amplifier

2. . . Antenna module

Ant. . . antenna

Flt. . . filter

Claims (6)

A Tuner can be used to support the receiving operation of a Digital Television signal and an Analog Television signal. The Tuner includes: a Low Noise Amplifier for receiving An input RF signal and a processed RF signal; a Quadrature Mixer for receiving and down-converting the processed RF signal to generate a low intermediate frequency ( a low-frequency signal (Low IF) signal; a channel filter for filtering the low-IF signal to generate a first signal corresponding to the signal band of the digital television; An up-converting module for up-converting the low-IF signal to generate a second signal, the second signal corresponding to a signal band of the analog television; and a switching circuit controlled by a selective signal selective One of the channel filter and the up-conversion module is enabled to selectively provide one of the first and second signals. The tuned module of claim 1, wherein the up-conversion module comprises: a filter for filtering second-order harmonic components and third-order harmonic components of the low-IF signal to generate a filtered low-IF signal; and an Up Mixer for mixing a reference signal and the filtered low-IF signal to generate the second signal. The modulating device of claim 2, wherein the up-converting module further comprises: an oscillator for providing an oscillating signal; and a frequency divider for generating the frequency according to the oscillating signal The reference signal is provided to the up-converter. The tuned module of claim 2, wherein the up-converter module further comprises: a driver amplifier for amplifying the second signal generated by the up-converter mixer. The tuned device of claim 1, wherein the orthogonal mixer comprises: a signal converter for converting the processed RF signal to generate a corresponding one of the RF signals; A Mixer is used to mix an orthogonal signal and the RF complex signal to generate a low intermediate frequency orthogonal signal; and an IF Poly-phase Filter And filtering the low intermediate frequency orthogonal signal to generate the low intermediate frequency signal. The modulating device of claim 5, wherein the quadrature mixer further comprises: an oscillator for providing an oscillating signal; and a frequency divider for dividing the frequency by the oscillating signal The orthogonal signal.