KR20110012808A

KR20110012808A - Broadcast reciever performing loop-through without power supply

Info

Publication number: KR20110012808A
Application number: KR1020090070680A
Authority: KR
Inventors: 오호진
Original assignee: 삼성전기주식회사
Priority date: 2009-07-31
Filing date: 2009-07-31
Publication date: 2011-02-09

Abstract

PURPOSE: A broadcast receiver performing loop-through without power supply is provided to perform a loop-through function without power supply by amplifying an RF broadcasting signal after distributing an RF broadcasting signal through a Balun circuit unit. CONSTITUTION: A Balun circuit unit(21) splits an RF broadcasting signal received from an antenna into a loop-through signal and a tuning signal, and a low-noise amplifier(22) removes a noise from the RF broadcasting signal, then amplifies the noise-removed RF broadcasting signal. A tuning unit(23) tunes the amplified RF broadcasting signal and outputs the tuned RF broadcasting signal as data. The tuner unit(23a) converts the amplified RF broadcasting signal into an intermediate frequency.

Description

BROADCAST RECIEVER PERFORMING LOOP-THROUGH WITHOUT POWER SUPPLY}

The present invention relates to a broadcast receiver, and more particularly, to a broadcast receiver capable of looping through without a power supply.

DVB-C is a standard for digital cable broadcasting. DVB-C is a module that can receive the transmitted signal using Quadrature Amplitude Modulation (hereinafter referred to as 'QAM'), selects a desired channel, amplifies the signal, and then uses an intermediate frequency (Intermediate Frequency). And a demodulator for demodulating the QAM modulated IF frequency outputted from the tuner to a baseband frequency to generate broadcast data.

Conventional broadcast receivers should always be powered on for a separate loop through function.

1 is a block diagram showing a conventional broadcast receiver. Referring to FIG. 1, the conventional broadcast receiver 10 includes a low noise amplifier 11, a balun circuit 12, and a tuning unit 13, and the tuning unit 13 is a tuner unit 13a. And a demodulator 13b.

The low noise amplifier 11 amplifies an RF broadcast signal input from an input terminal ANT IN and provides the amplified RF broadcast signal to the balun circuit unit 12.

The balun circuit unit 12 is composed of two inductors and distributes signals according to the ratio of each inductor value. The balun circuit unit 12 distributes the RF broadcast signal amplified from the low noise amplifier 11 according to the ratio of two inductors. Thus, one of the divided signals is output to the loop through stage (port 2 in FIG. 1) to perform a loop through function, and the other is output to the tuning unit 13 to output broadcast data according to the received signal.

As described above, the tuning section 13 is composed of a tuner section 13a and a demodulation section 13b, and the tuner section 13a intermediates the RF broadcast signal distributed through the balun circuit section 12. The demodulator 14 demodulates the intermediate frequency IF converted from the tuner 13 to a baseband frequency to generate broadcast data.

FIG. 2 is a graph showing the transmission characteristic S21 [dB] of each S-parameter when the conventional broadcast receiver 10 is ON or OFF. Referring to FIG. 2, when the conventional broadcast receiver 10 is on (see A graph), the transmission characteristic S21 is in a range of −2 to +2 dB, and when the conventional broadcast receiver 10 is off (B graph). The transmission characteristic S21 is in the range of -30 to -20 dB.

The conventional broadcast receiver 10 has a low noise amplifier 11 as an active element and a balun circuit unit 12 as a passive element between an ANT input and an ANT output. At this time, power is applied to the conventional broadcast receiver 10. When it is in the on state, the low noise amplifier 11 operates well to perform a loop through function, while when the power is interrupted to the conventional broadcast receiver 10 and is turned off, the power is supplied to the low noise amplifier 11. Because there is no supply, approximately 25dB of loss occurs, which means that the transmission efficiency is low, which means that the loop-through function is not performed well.

In other words, although the conventional broadcast receiver 10 does not need the operation of a tuner in a set-top-box, power is applied to the tuner, which wastes unnecessary power. Therefore, there is a need for a broadcast receiver to use the loop through function even when no power is supplied.

The present invention has been made to solve the problems of the prior art as described above, by designing a balun circuit portion in front of the low noise amplification unit, by first distributing and then amplifying the RF broadcast signal through the balun circuit portion broadcast receiver capable of loop through at no power supply The purpose is to provide.

In order to achieve the above object, a broadcast receiver capable of loop through at a no power supply according to an embodiment of the present invention includes a balun circuit unit for distributing an RF broadcast signal received from an antenna into a signal for loop through and a signal for tuning; And a low noise amplifier for removing noise and amplifying the RF broadcast signal distributed from the balun circuit unit, and a tuning unit for tuning and outputting the amplified RF broadcast signal as broadcast data.

The tuning unit includes a tuner unit for converting the RF broadcast signal amplified by the low noise amplifier into an intermediate frequency, and a demodulator for demodulating the intermediate frequency converted from the tuner unit into baseband frequencies to generate broadcast data. It is characterized by including.

In addition, the balun circuit portion is characterized by consisting of two inductors, the balun circuit portion is characterized in that to distribute the signal in accordance with the ratio of the two inductor values.

As described above, according to the broadcast receiver capable of loop-through at a non-power supply according to an embodiment of the present invention, the loop-through function can be used without supplying power, thereby preventing unnecessary waste of power.

In addition, according to an embodiment of the present invention, a broadcast receiver capable of looping through a power supply according to an embodiment of the present invention has an effect of having high utilization because the design of the set-top box is convenient and can cope with various requirements of the set engineer.

The features and advantages of the present invention will become apparent from the following drawings and detailed description of the invention.

Hereinafter, a broadcast receiver capable of looping through a non-power supply according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. And duplicate description thereof will be omitted.

3 is a block diagram illustrating a structure of a broadcast receiver capable of looping through a power supply according to an embodiment of the present invention. Referring to FIG. 3, the broadcast receiver 20 includes a balun circuit unit 21, a low voltage amplifier 22, and a tuning unit 23, and the tuning unit 23 is a tuner unit 23a. And a demodulation section 23b.

The balun circuit unit 21 distributes signals according to a ratio of two inductor values. When an RF broadcast signal received from an antenna is input to port 1, the balun circuit unit 21 may have 1: 1 balun or 1: 2 balun or The RF broadcast signal is distributed in a 1: 3 balun or the like. The distributed RF broadcast signal is provided to the loop through stage (such as port 2) and the tuning unit, respectively. The description of the balun circuit unit 21 will be described later in more detail with reference to FIG. 4.

The low voltage amplifier 22 provides the tuning unit 23 with the RF broadcast signal distributed from the balun circuit unit 21 to minimize the noise component and amplify only the signal component.

Here, the tuning unit 23 is for outputting broadcast data by tuning the RF broadcast signal distributed from the low noise amplifier 22. As described above, the tuner unit 23a and the demodulator 23b. It consists of.

The tuner section 23a converts the RF broadcast signal provided from the low voltage amplifier section 22 into an intermediate frequency and provides the demodulation section 23b.

The demodulator 23b demodulates the intermediate frequency provided from the tuner unit 23a to a baseband frequency to generate broadcast data. The broadcast data includes, for example, audio data and video data.

4 shows a detailed circuit diagram of the balun circuit section 21 of FIG. Referring to FIG. 4, the balun circuit unit 21 according to an exemplary embodiment may include a first inductor 210, a second inductor 230, a first variable capacitor 240, and a second variable capacitor 250. It may include.

In order to form a balun transformer in which both ends of the second inductor 23 are used as input / output terminals of the balanced signal, the central portion 230d of the electrical length of the second inductor 230 may be connected to the ground portion. In the present embodiment, the first variable capacitor 240 may be connected between the central portion 230d of the length of the second inductor 230 and the ground portion.

The first inductor 220 and the second inductor 230 form an electromagnetic coupling with each other, the second inductor 230 with respect to an unbalanced signal input to one port 220a of the first inductor 220 The two ports 230a and 230b may output balanced signals having the same size and having a phase difference of 180 degrees. In practice, however, the strength of the coupling varies according to the energy distribution, so the two output ports may differ in phase and magnitude of the signal. In this case, the capacitance value of the first variable capacitor 240 may be adjusted to correct signal phase differences and magnitude levels of the two ports.

In the present embodiment, the second variable capacitor 250 may be connected to one end 220b of the first inductor 220. By adjusting the capacitance of the second variable capacitor 250, the phase and magnitude of the unbalanced signal input to the first inductor 220 may be adjusted.

Therefore, in the present embodiment, the first variable capacitor 240 connected to the center of the length of the second inductor 230 and the second variable capacitor 250 connected to one end of the first inductor 220 are respectively adjusted. This compensates for the characteristics of the balun transformer, which can change with ambient conditions or process changes.

5 is a graph showing a transmission characteristic (S21) [dB] when the power is turned on / off in the broadcast receiver 20 capable of looping through a power supply according to an embodiment of the present invention.

Referring to FIG. 5, it can be seen that the transmission characteristic S21 is both -4 dB to -2 dB when the power is turned on / off, and is very low. In other words, the broadcast receiver 20 according to the present invention can be seen that the transmission efficiency does not decrease when power is supplied as well as when the power is not supplied, which can function as a loop through function even when the power is not supplied. It means that there is.

Although the above has been described with reference to a preferred embodiment of the present invention, those skilled in the art to which the present invention pertains without departing from the spirit and scope of the present invention as set forth in the claims below It will be appreciated that modifications and variations can be made.

1 is a block diagram showing a conventional broadcast receiver.

FIG. 2 is a graph showing transmission characteristics (S21) when the broadcast receiver of FIG. 1 is turned on or off.

3 is a block diagram illustrating a broadcast receiver according to an embodiment of the present invention.

4 is a detailed circuit diagram of the balun circuit unit of FIG. 3.

FIG. 5 is a graph showing transmission characteristics (S21) when the broadcast receiver of FIG. 3 is turned on / off.

10, 20: broadcast receiver 11, 22: low noise amplifier

12, 21: balun circuit part 13, 23: tuning part

13a, 23a: tuner section 13b, 23b: demodulation section

Claims

A balun circuit unit configured to distribute the RF broadcast signal received from the antenna into a signal for loop through and a signal for tuning;

A low noise amplifier for removing noise and amplifying the RF broadcast signal distributed from the balun circuit unit; And

And a tuning unit for tuning the RF broadcast signal amplified by the low noise amplifier and outputting the broadcast data as broadcast data.

The method of claim 1, wherein the tuning unit,

A tuner unit for converting the RF broadcast signal amplified by the low noise amplifier into an intermediate frequency; And

And a demodulator for demodulating the intermediate frequency converted from the tuner to a baseband frequency to generate broadcast data.

The broadcast receiver of claim 1, wherein the balun circuit part comprises two inductors.

4. The broadcast receiver of claim 3, wherein the balun circuit unit distributes a signal according to a ratio of the two inductor values.