KR20060117102A - Receiver for satellite digital multimedia broadcasting including bypass circuit - Google Patents

Abstract

A satellite DMB(Digital Multimedia Broadcasting) receiving with a bypass circuit is provided to selectively filter or bypass an intermediate frequency band in response to an input signal band and improve the performance of the receiver by reducing noise and loss of load. A satellite DMB receiver with a bypass circuit includes an RF(Radio Frequency) stage(210), an IF(Intermediate Frequency) stage(220), and a frequency supply(230). The RF stage converts a DMB frequency received from an antenna into an intermediate frequency. The IF stage converts the intermediate frequency into a base-band signal. The frequency supply supplies a frequency such that the signal received by the RF stage is converted into the intermediate frequency. The IF stage includes a first receiving unit(220a) and a second receiving unit. The first receiving unit includes a first bypass filter(221a) having a first filter and a first switch connected in parallel and a first low noise amplifier(222a) and forms an I-channel. The second receiving unit includes a second bypass filter(221b) having a second filter and a second switch connected in parallel and a second low noise amplifier(222b) and forms a Q-channel. When the first and second switches are on, the intermediate frequency of the I/Q channel bypasses. When the first and second switches are off, the intermediate frequency of the I/Q channel are filtered by the first and second filters.

Description

Receiver for satellite digital multimedia broadcasting with bypass circuit. {RECEIVER FOR SATELLITE DIGITAL MULTIMEDIA BROADCASTING INCLUDING BYPASS CIRCUIT}

1 is a block diagram of a conventional satellite digital multimedia broadcasting receiver.

2 is a block diagram of a satellite digital multimedia broadcasting receiver having a bypass circuit according to an embodiment of the present invention.

3 is a block diagram of a satellite digital multimedia broadcasting receiver having a bypass circuit according to another embodiment of the present invention.

4 is a block diagram of a satellite digital multimedia broadcasting receiver having a bypass circuit according to another embodiment of the present invention.

<Explanation of symbols on main parts of the drawings>

210, 310, 410: RF stage 220, 320, 420: IF stage

220a, 320a, 420a: first receiver 220b, 320b, 420b: second receiver

203a, 303a, 403a: first filter 203b, 303b, 403b: second filter

SW21a, SW31a, SW41a: first switch SW21b, SW31b, SW41b: second switch

The present invention relates to a receiver, and more particularly to a receiver for satellite digital multimedia broadcasting.

1 is a block diagram of a conventional satellite digital multimedia broadcasting receiver.

As shown, the conventional satellite digital multimedia broadcasting receiver 100 includes a low noise amplifier (LNA) 101, a first mixer 102a, a second mixer 102b, and a first low band. Low pass filter (LPF) 103a, second LPF 103b, first LNA 104a, second LNA 104b, phase locked loop (PLL) 105, local oscillator (Local Oscillator; LO) 106 and Phase Local Oscillator (PLO) 107.

Here, only the desired frequency band is selectively filtered among the intermediate frequency bands output from the first or second mixers 102a and 102b in the first or second LPFs 103a and 103b, respectively.

Currently, the satellite DMB frequency band is used by being assigned a frequency band of 2605 MHz to 2655 MHz, and the frequency band used by being allocated to mobile carriers is divided into 2605 MHz to 2630 MHz and 2630 MHz to 2655 MHz to serve. Therefore, when frequency signals of different bands are simultaneously input and converted into intermediate frequencies, unwanted interference signals are generated and a filtering process must be performed to remove noise.

However, when only one of the above-mentioned two band signals is input, since no interference signal is generated, this filtering process is unnecessary.

Current satellite DMB receivers go through the filtering process of all signals without such filtering or bypass separation.

The filter circuit selectively removes noise in the output signal band of the receiver by selectively selecting a band of a frequency to be received, but the filter itself can be treated as a load, and the presence of a filter capable of acting as a load is a satellite digital multimedia. There is a problem that may adversely affect the overall power consumption, size and process of the portable mobile communication terminal that can receive a broadcast.

An object of the present invention for solving the above problems is to provide a satellite digital multimedia broadcasting receiver capable of selectively filtering or bypassing an intermediate frequency band according to an input signal band.

Another object of the present invention is to provide a receiver having improved performance by reducing noise and load loss caused by a device.

A satellite digital multimedia broadcasting receiver having a bypass circuit according to the present invention for solving the above problems is an RF stage for converting DMB (DIGITAL MULTIMEDIA BROADCASTING) frequency received from an antenna to an intermediate frequency; An IF stage for converting the intermediate frequency changed in the RF stage into a base-band signal; And a frequency supply unit configured to supply a frequency to convert the signal received at the RF stage into an intermediate frequency, wherein the IF stage includes a first bypass filter unit and a first low noise in which a first filter and a first switch are connected in parallel. A first receiver configured as an amplifier and forming an I-channel, a second bypass filter unit in which a second filter and a second switch are connected in parallel, and a second receiver configured as a second low noise amplifier and forming a Q-channel. And the intermediate frequency of the I / Q channel is bypassed when the first and second switches are on, and the intermediate frequency of the I / Q channel is zero when the first and second switches are off. And filtered by the first and second filters.

Here, the DMB frequency band is 2605 (MHz) to 2655 (MHz).

Here, the DMB frequency band is divided into a first DMB frequency band of 2605 (MHz) to 2630 (MHz) frequency band and a second DMB frequency band of 2630 (MHz) to 2655 (MHz) frequency band, wherein the first or When only one of the second DMB frequency band signals is an input signal, the first and second switches are turned on to implement an intermediate frequency of the I / Q channel.

Here, the first or second mixer is preferably a down-conversion mixer.

Here, the phase locked loop is preferably composed of a frequency combiner and a voltage controlled oscillator.

Here, the low noise amplifiers of the first and second receivers may be implemented as a programmable gain control or a variable gain control amplifier.

Advantages and features of the present invention, and methods for achieving them will be apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms, and only the embodiments make the disclosure of the present invention complete, and the general knowledge in the art to which the present invention belongs. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram of a satellite digital multimedia broadcasting receiver having a bypass circuit according to an embodiment of the present invention.

As shown, the satellite digital multimedia broadcasting receiver 200 includes an RF stage 210, an IF stage 220, and a frequency supply unit 230.

<Circuit configuration>

The RF stage 210 includes a low noise amplifier (LNA) 211 for RF, a first mixer 212a and a second mixer 212b.

The IF stage 220 includes a first receiver 220a and a second receiver 220b.

The first receiver 220a includes a first bypass filter 221a and a first low noise amplifier 222a.

The first bypass filter unit 221a is composed of a first filter 221a1 and a first switch SW21a, and is connected in parallel with each other.

The second receiver 220b includes a second bypass filter 221b and a second low noise amplifier 222b.

The second bypass filter unit 221b is composed of a second filter 221b1 and a second switch SW21b and is connected in parallel with each other.

The frequency supply unit 230 includes a phase locked loop (PLL) 231, a local oscillator (LO) 232, and a phase local oscillator (PLO) 233. .

<Connection relationship>

The satellite signal is input to the input terminal of the RF LNA 211 of the RF terminal 210 of the satellite digital multimedia broadcasting receiver 200, and the output of the RF LNA 211 is the first mixer 212a and the second mixer ( 212b).

Here, the output frequency of the PLL 231 of the frequency supply unit 230 is input to the LO 232, the output of the LO 232 is input to the PLO 233, and the outputs of the PLO 232 are each in phase ( In-phase and quadrature phase are divided so that the in-phase frequency is supplied to the first mixer 212a, and the quadrature frequency is supplied to the second mixer 212b.

The output of the first mixer 212a is one end of the first switch SW21a connected in parallel with the first filter 221a1 of the first bypass filter 221a of the first receiver 220a of the IF stage 220. The other end of the first filter 221a1 and the other end of the first switch SW21a are commonly connected to the input end of the first LNA 222a to form an I-channel.

The output of the second mixer 212b is one end of the second switch SW21b connected in parallel with the second filter 221b1 of the second bypass filter 221b of the second receiver 220b of the IF stage 220. The second end of the second filter 221b1 and the second end of the second switch SW21b are commonly connected to the input terminal of the second LNA 222b to form a Q-channel.

<Description of operation>

The RF LNA 211 amplifies the signal while suppressing the amplification of the weak satellite signal to the noise as much as possible, and transmits the signal to the respective means of the first mixer 212a and the second mixer 212b.

The PLL 231 allows the output frequency of the LO 232 to be fixed at a constant frequency without shaking, and precisely adjusts the voltage of the voltage control oscillator (VCO) used in the LO 232 to control the LO 232. Move the output frequency to the desired frequency and fix it.

In addition, the PLL 231 is composed of a frequency combiner and a VCO, and the VCO can handle the Digital Multimedia Broadcasting (DMB) -S frequency range.

Here, the combiner is composed of a 20-bit sigma-delta fractional-N architecture and has a good noise characteristic according to fast switching, ultra high resolution frequency, and broadband.

LO 232 oscillates a frequency for converting the satellite signal to base-band.

PLO 233 generates a frequency in phase or quadrature (90 °) and supplies it to mixers 212a and 212b, respectively.

The first mixer 212a is a mixer acting as a down-converter, and the same frequency is amplified through the LNA 211 and the same through the PLL 231, the LO 232, and the PLO 233. Mixing phase frequencies converts the received satellite frequencies into in-phase baseband frequency signals.

The first LPF 221a1 filters the desired frequency signal selectively among the frequency signals output from the first mixer 212a.

The first LNA 222a is configured as a programmable gain amplifier (PGA) or a variable gain amplifier (VGA) to form an I-channel with the frequency signal converted from the satellite frequency signal to the baseband. .

In the same structure, the first mixer 212b is a mixer which acts as a downconversion, and mixes the amplified frequency through the LNA 211 and the quadrature frequencies through the PLL 231, the LO 232, and the PLO 233. Converts the received satellite frequency into a quadrature baseband frequency signal.

Here, the first bypass filter unit 221a of the first receiver 220a and the second bypass filter unit 221b of the second receiver 220b are implemented in the chip of the receiver 200 so that the first filter ( 221a1 and the second filter 221b1 are configured to be selectively used.

The band of the satellite signal input to the RF stage 210 is 2605 (MHz) to 2655 (MHz), and the band of the satellite signal is the first satellite DMB band of 2605 (MHz) to 2630 (MHz) and 2630 (MHz) to The service is performed by being allocated to a second satellite DMB band of 2655 (MHz).

Here, when the first satellite DMB band and the second satellite DMB band signal are simultaneously input to the RF terminal 210, noise frequencies are generated due to mutual interference, and filters 221a1 and 221b1 are required to remove such noise frequencies. Done.

However, when only one signal of the first satellite DMB band signal and the second satellite DMB band signal is input to the RF terminal 210, the intermediate frequency region in the IF terminal 220 may be severely interfered with each other. Since there is no frequency in the band, the interference in the intermediate frequency region in the IF stage 220 is very weak.

Therefore, since the role of the first or second filters 221a1 and 221b1 is meaningless, the first or second filters SW21a and SW21b for bypass do not pass through the first or second filters 221a1 and 221b1. It will bypass.

This reduces the power consumption of the entire receiver and the noise components caused by the first or second filters 221a1 and 221b1.

3 to 4 are block diagrams of a satellite digital multimedia broadcasting receiver having a bypass circuit according to another embodiment of the present invention.

Since the device configuration and operation of the receiver illustrated in FIGS. 3 to 4 are the same as those described in FIG. 2, only the configuration of the bypass filter unit will be described below.

As shown in FIG. 3, the first receiver 320a is connected to the first bypass filter 321a and the first low noise amplifier 322a in parallel with the bypass filter illustrated in FIG. 2. The first switch SW31a may be implemented outside the chip of the receiver 300, and the second receiver 320b may have the same configuration as the first receiver 320a.

In addition, as illustrated in FIG. 4, the first receiver 420a is connected to the first bypass filter 421a and the first low noise amplifier 422a in parallel with the bypass filter illustrated in FIG. 2. Although the same, the first filter 421a1 is implemented outside the chip of the receiver 400, the second receiver 420b also has the same configuration as the first receiver 420a.

This structure enables selective filtering or bypass of intermediate frequency bands in receivers receiving satellite digital multimedia broadcasting frequencies, and improves receiver performance by reducing noise and load loss caused by elements that are not required by bypass. It becomes possible to make it.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the technical configuration of the present invention described above may be modified in other specific forms by those skilled in the art to which the present invention pertains without changing its technical spirit or essential features. It will be appreciated that it may be practiced. Therefore, the above-described embodiments are to be understood as illustrative and not restrictive in all respects, and the scope of the present invention is indicated by the appended claims rather than the detailed description, and the meaning and scope of the claims and All changes or modifications derived from the equivalent concept should be interpreted as being included in the scope of the present invention.

According to the above-described configuration of the present invention, it is possible to implement a satellite digital multimedia broadcasting receiver capable of selectively filtering or bypassing an intermediate frequency band in a receiver for receiving a satellite digital multimedia broadcasting frequency.

In addition, it is possible to improve the performance of the receiver by reducing noise and load loss caused by unnecessary elements by the bypass.

Claims (6)

An RF stage for converting a DMB (DIGITAL MULTIMEDIA BROADCASTING) frequency received from an antenna into an intermediate frequency; An IF stage for converting the intermediate frequency changed in the RF stage into a base-band signal; And And a frequency supply unit configured to supply a frequency to convert the signal received at the RF terminal into an intermediate frequency. The IF stage includes a first bypass filter unit in which a first filter and a first switch are connected in parallel, a first low noise amplifier, and a first receiver configured to form an I-channel, and a second filter and a second switch in parallel. A second receiver comprising a second bypass filter unit and a second low noise amplifier and forming a Q-channel, If the first and second switches are on, the intermediate frequency of the I / Q channel is bypassed. If the first and second switches are off, the intermediate frequency of the I / Q channel is first and second. Receiver for satellite digital multimedia broadcasting with a bypass circuit, filtered by two filters. The method of claim 1, The DMB frequency band is 2605 (MHz) to 2655 (MHz), the satellite digital multimedia broadcasting receiver having a bypass circuit. The method of claim 2, The DMB frequency band is divided into a first DMB frequency band of 2605 (MHz) to 2630 (MHz) frequency band and a second DMB frequency band of 2630 (MHz) to 2655 (MHz) frequency band, A satellite having a bypass circuit, in which the first and second switches are turned on and the intermediate frequency of the I / Q channel is bypassed when only one of the first or second DMB frequency band signals is an input signal. Receiver for digital multimedia broadcasting. The method of claim 1, The first or second mixer is a down-conversion mixer (Down-Conversion Mixer), a satellite digital multimedia broadcasting receiver having a bypass circuit. The method of claim 1, And said phase-locked loop is comprised of a frequency combiner and a voltage controlled oscillator. The method of claim 1, The low noise amplifiers of the first and second receivers are implemented as programmable gain control or variable gain control amplifiers.

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