CN102045080A - Radio frequency signal receiving device - Google Patents

Abstract

The invention relates to a radio frequency signal receiving device which comprises a first multiphase filter, a second multiphase filter, a first frequency mixing module, a selector switch and a low-pass filter module. The first polyphase filter receives a radio frequency input signal and generates a plurality of filtered radio frequency signals accordingly. The first frequency mixing module is used for mixing frequency according to the frequency reduction signals and the filtered radio frequency signals so as to generate a plurality of frequency reduction radio frequency signals. The switch receives the frequency-reducing radio frequency signal and transmits the frequency-reducing radio frequency signal to the first channel or the second channel according to the selection signal. The second polyphase filter receives the down-converted RF signal from the second channel for filtering. The low-pass filter module receives the filtered frequency-reduced radio-frequency signal or the frequency-reduced radio-frequency signal transmitted from the first channel to perform low-pass filtering, so as to generate a low-intermediate-frequency signal or a zero-intermediate-frequency signal. The radio frequency signal receiving device provided by the invention can simultaneously provide three different radio frequency signal receiving modes.

Description

RF signal receiving device

technical field

The invention relates to a radio frequency signal receiving device.

Background technique

In today's technology, RF signal receivers applied to System ON Chip (SOC) can generally be divided into two types. One of them is the so-called direct conversion receiver architecture, and the other is the so-called low intermediate frequency receiver architecture. These two RF signal receiver architectures each have different advantages and disadvantages. Usually, designers will choose the corresponding architecture according to different applications or different considerations.

The following uses the direct conversion radio frequency signal receiver architecture as an example to illustrate. FIG. 1 is a schematic diagram of a conventional radio frequency signal receiver 100 . Referring to FIG. 1 , the radio frequency signal receiver 100 includes a low noise amplifier 110 , low pass filters 121 , 122 , mixers 131 , 132 , a voltage controlled oscillator 133 and output buffers 141 , 142 . The RF signal receiver 100 receives the input signal IN through the low-noise amplifier 110, and after the signal processing process of the mixers 131, 132 and the voltage-controlled oscillator 133, the output buffers 141, 142 output the so-called zero-IF output signal ZIFOUT1 , ZIFOUT2.

Please note here that the RF signal receiver 100 shown in FIG. 1 can only generate direct-conversion zero-IF output signals, and cannot generate output signals of so-called low-IF RF signal receiver architectures. That is to say, when the system needs to receive RF input signals in two modes, two independent RF signal receivers must be constructed. In this way, the circuit area on the chip is wasted, and the cost of the chip is also increased.

Contents of the invention

The purpose of the present invention is to provide a radio frequency signal receiving device that can simultaneously provide three different radio frequency signal receiving modes.

An embodiment of the present invention provides a radio frequency signal receiving device, including first and second polyphase filters, a first frequency mixing module, a switch, and a low-pass filter module. The first polyphase filter receives a radio frequency input signal and generates a filtered radio frequency signal accordingly. The first frequency mixing module is connected to the first polyphase filter, and performs frequency mixing according to the down-frequency signal and the post-wave radio frequency signal to generate a down-frequency radio frequency signal. The switching switch receives the down-frequency radio frequency signal, and transmits the down-frequency radio frequency signal to the first channel or the second channel according to the selection signal. The second polyphase filter is connected to the switch and receives the down-frequency radio frequency signal transmitted by the second channel. The low-pass filter module is connected to the second polyphase filter and the switch or receives the down-frequency radio frequency signal transmitted from the first channel for low-pass filtering, thereby generating a low-IF signal or a zero-IF signal.

In an embodiment of the present invention, the above radio frequency signal receiving device further includes an output buffer module. The output buffer module is connected with the low-pass filter module to receive and amplify the low-IF signal or zero-IF signal, and generate low-IF output signal or zero-IF output signal.

In an embodiment of the present invention, the above-mentioned radio frequency signal receiving device further includes a second frequency mixing module connected between the low-pass filter module and the output buffer module. When the low-pass filter module generates a zero-IF signal, the second mixing module can mix the second local signal with the zero-IF signal to generate an IF signal.

In an embodiment of the present invention, the above radio frequency signal receiving device further includes an up-frequency voltage controlled oscillator. The up-frequency voltage controlled oscillator is connected to the second mixing module for generating up-frequency signals.

In an embodiment of the present invention, the output buffer module also receives and amplifies the intermediate frequency signal to generate the intermediate frequency output signal.

In an embodiment of the present invention, the above-mentioned output buffer module includes a plurality of amplifiers. The amplifier is connected with a low-pass filter module to receive and amplify low intermediate frequency signals or zero intermediate frequency signals and intermediate frequency signals.

In an embodiment of the present invention, each of the aforementioned amplifiers is a programmable gain amplifier.

In an embodiment of the present invention, the above-mentioned radio frequency signal receiving device further includes a down-frequency voltage-controlled oscillator connected to the first mixing module for generating down-frequency signals.

In an embodiment of the present invention, the above-mentioned low-pass filter module includes a first low-pass filter, a second low-pass filter and a switch. The first low-pass filter is connected to the switch and the second polyphase filter, and is used for receiving the output of the second polyphase filter or a part of the down-frequency radio frequency signal transmitted from the first channel for low-pass filtering. The second low-pass filter is connected to the first low-pass filter and the switching switch, and is used for receiving another part of the down-frequency radio frequency signal transmitted from the first channel or the output of the first low-pass filter for filtering. The switch is connected between the first low-pass filter and the second low-pass filter, and is used to turn on or turn off the connection between the first and second low-pass filters.

In one embodiment of the present invention, when the first low-pass filter receives the output of the second polyphase filter and the second low-pass filter receives the output of the first low-pass filter for filtering, the low-pass filter The module produces a low-IF signal.

In one embodiment of the present invention, when the first low-pass filter receives a part of the down-frequency radio frequency signal transmitted from the first channel and the second low-pass filter receives part of the down-frequency radio frequency signal transmitted from the first channel When the other part is used for filtering, the low-pass filter module produces a zero-IF signal.

In an embodiment of the present invention, the above-mentioned first polyphase filter is a radio frequency polyphase filter.

In an embodiment of the present invention, the above-mentioned second polyphase filter is an intermediate frequency polyphase filter.

In an embodiment of the present invention, the above radio frequency signal receiving device further includes a low noise amplifier. The low noise amplifier is connected to the path where the first polyphase filter receives the radio frequency input signal.

Based on the above, the present invention utilizes the same circuit architecture to implement a direct conversion receiver, a low intermediate frequency receiver, and an intermediate frequency receiver. The hardware performance in the radio frequency signal receiving device is effectively utilized to enhance the competitiveness of the product.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail with reference to the accompanying drawings.

Description of drawings

FIG. 1 is a schematic diagram of a conventional radio frequency signal receiver 100 .

FIG. 2 is a schematic diagram of a radio frequency signal receiving device 200 according to an embodiment of the present invention.

3A and 3B are schematic diagrams of the same operation mode of the radio frequency signal receiving device 200 according to the embodiment of the present invention.

FIG. 4 is a schematic diagram of a radio frequency signal receiving device 400 according to another embodiment of the present invention.

Description of main component symbols:

100: RF signal receiver; 200, 400: RF signal receiving device;

110, 270, 470: low noise amplifier; 131, 132: mixer;

133: voltage controlled oscillator; 280, 480: down-frequency voltage controlled oscillator;

454: up-frequency voltage controlled oscillator; 141, 142: output buffer;

220, 420, 453: mixing module; 230, 430: switch;

250, 450: low-pass filter module; 260, 460: output buffer module;

OSC1: down-frequency signal; OSC2: up-frequency signal;

SEL: selection signal; IN: input signal;

RFIN: RF input signal; ZIF1, ZIF2: Zero-IF signal;

IF: intermediate frequency signal; LIF: low intermediate frequency signal;

IFOUT: intermediate frequency output signal; LIFOUT: low intermediate frequency output signal;

CH1: first channel; CH2: second channel;

SW1: switch;

121, 122, 251, 252, 451, 452: low-pass filter;

210, 240, 410, 440: polyphase filter;

261, 262, 263, 462, 463, 464: Amplifiers;

ZIFOUT1, ZIFOUT2, ZIFOUT: Zero-IF output signal.

Detailed ways

FIG. 2 is a schematic diagram of a radio frequency signal receiving device 200 according to an embodiment of the present invention. Please refer to FIG. 2 below, the radio frequency signal receiving device 200 includes polyphase filters 210, 240, a mixing module 220, a switch 230, a low-pass filter module 250, an output buffer module 260, a low noise amplifier 270 and a frequency voltage controlled oscillator 280. Wherein, the low noise amplifier 270 is connected to the polyphase filter 210 and receives the radio frequency input signal RFIN for amplifying the radio frequency input signal RFIN to transmit to the polyphase filter 210 . The polyphase filter 210 receives a radio frequency input signal RFIN and generates a pair of radio frequency signals at 90 degrees to each other accordingly. These 90-degree RF signals are sent to the mixing module 220 connected to the polyphase filter 210 . The frequency mixing module 220 also receives the down-frequency signal OSC1. Moreover, the frequency mixing module 220 performs frequency mixing according to the down-frequency signal OSC1 and the filtered radio frequency signal, and then generates a pair of down-frequency radio signals with a 90-degree mutual angle.

Please note here that the down-frequency signal OSC1 is generated by the down-frequency voltage controlled oscillator 280 . When the down-frequency signal OSC1 is to be adjusted, it is only necessary to change the voltage received by the down-frequency voltage control oscillator 280 . That is to say, the down-frequency signal OSC1 can be dynamically adjusted by hardware or software.

The switching switch 230 is connected to the mixing module 220 and receives the down-converted radio frequency signal generated by the mixing module 220 . The switch 230 is controlled by the selection signal SEL. That is to say, the switch 230 selects to transmit the down-frequency radio frequency signal to the first channel CH1 or the second channel CH2 according to the selection signal SEL. The selection signal SEL is determined according to the radio frequency signal receiving and processing method to be performed by the radio frequency signal receiving device 200 . If the RF signal receiving device 200 is set to generate an output signal of zero intermediate frequency or intermediate frequency, the selection signal SEL is set to control the switch 230 to transmit the down-converted RF signal to the first channel CH1. In contrast, if the RF signal receiving device 200 is set to generate a low-IF output signal, the selection signal SEL is set to control the switch 230 to transmit the down-frequency RF signal to the second channel CH2.

The polyphase filter 240 is connected to the second channel CH2 of the switch 230 to receive the down-frequency radio frequency signal transmitted by the second channel CH2 for filtering. In other words, the polyphase filter 240 only works when the switch 230 transmits the down-converted RF signal to the second channel CH2 according to the selection signal SEL.

The low-pass filter module 250 is connected to the first channel CH1 of the switch 230 and the polyphase filter 240 . The low-pass filter module 250 receives the output of the polyphase filter 240 or receives the down-frequency RF signal transmitted from the first channel CH1 for filtering. The low-pass filter module 250 includes series-connected low-pass filters 251, 252. When the low-pass filter module 250 received the output of the polyphase filter 240, the switch SW1 was turned on, and the low-pass filters 251, 252 252 sequentially filters the output of polyphase filter 240 and outputs a low intermediate frequency signal from low pass filter 252 . If when the low-pass filter module 250 receives the down-frequency radio frequency signal transmitted by the first channel CH1, the switch SW1 is closed (disconnected), and the low-pass filter 251 receives the down-frequency radio frequency signal transmitted by the first channel CH1 A part of the signal is filtered, while the low-pass filter 252 receives the other part of the down-frequency RF signal transmitted from the first channel CH1 for filtering, and the low-pass filters 251 and 252 output zero-IF signals respectively.

The output buffer module 260 is connected to the low-pass filter module 250 . The output buffer module 260 receives the low-IF signal or zero-IF signal generated by the low-pass filter module 250 and amplifies the received low-IF signal or zero-IF signal to generate a low-IF output signal LIFOUT or a zero-IF output signal ZIFOUT.

Incidentally, the polyphase filter 210 in this embodiment is an RF poly-phase filter (RF poly-phase filter) and the polyphase filter 240 is an IF poly-phase filter (IF poly-phase filter).

The following will further introduce the action details of the radio frequency signal receiving device 200 according to the embodiment of the present invention, so that those skilled in the art can easily understand and implement the embodiment of the present invention accordingly.

3A and 3B are schematic diagrams of different operation modes of the radio frequency signal receiving device 200 according to the embodiment of the present invention. Please refer to FIGS. 3A and 3B below. In FIG. 3A , the radio frequency signal receiving device 200 is configured to receive the radio frequency input signal RFIN by outputting a low intermediate frequency output signal. The radio frequency input signal RFIN is received and amplified by the low noise amplifier 270 and transmitted to the polyphase filter 210 . The mixing module 220 receives the output of the polyphase filter 210 and generates a down-frequency radio frequency signal, and transmits the down-frequency radio frequency signal to the switch 230 . Here, the switch 230 transmits the down-frequency radio frequency signal to the polyphase filter 240 through the second channel CH2 according to the selection signal SEL.

The low-pass filter module 250 receives the output of the polyphase filter 240, and sequentially filters the output of the polyphase filter 240 through the low-pass filters 251 and 252 (at this time, the switch SW1 is turned on) to generate Low intermediate frequency signal LIF. The amplifier 261 in the output buffer module 260 receives and amplifies the low-IF signal LIF to generate a low-IF output signal LIFOUT.

In addition, in FIG. 3B , the radio frequency signal receiving device 200 is configured to receive the radio frequency input signal RFIN in a manner of outputting a zero-IF output signal. The radio frequency input signal RFIN is received and amplified by the low noise amplifier 270 and transmitted to the polyphase filter 210 . The mixing module 220 receives the output of the polyphase filter 210 and generates a down-frequency radio frequency signal, and transmits the down-frequency radio frequency signal to the switch 230 . Here, the switch 230 transmits the down-frequency radio frequency signal to the low-pass filter module 250 through the first channel CH1 according to the selection signal SEL. Here, the down-frequency radio frequency signal is divided into two parts and input to the low-pass filters 251 and 252 respectively. The low-pass filters 251 and 252 filter the part of the received down-frequency RF signal (the switch SW1 is turned off at this time), and then generate zero-IF signals ZIF1 and ZIF2.

The output buffer module 260 includes two amplifiers 262 , 263 . Amplifiers 261 and 262 respectively receive and amplify zero-IF signals ZIF1 and ZIF2 to generate zero-IF output signals ZIFOUT1 and ZIFOUT2 .

Please note that, as can be seen from FIGS. 3A and 3B and related descriptions, the RF signal receiving device 200 does not generate the low-IF signal LIF and the zero-IF signals ZIF1 and ZIF2 at the same time. Therefore, the amplifier 262 shown in FIG. 3B and the amplifier 261 shown in FIG. 3A can be implemented with the same amplifier.

In addition, in this embodiment, the amplifiers 261-263 may be implemented by a programmable gain amplifier (Programmable Gain Amplifier, PGA for short).

FIG. 4 is a schematic diagram of a radio frequency signal receiving device 400 according to another embodiment of the present invention. 4, the radio frequency signal receiving device 400 includes polyphase filters 410, 440, a mixing module 420, a switch 430, a low-pass filter module 450, an output buffer module 460, a low noise amplifier 470 and a Frequency Voltage Controlled Oscillator 480. Different from the previous embodiment, the RF signal receiving device 400 further includes a frequency mixing module 453 and an up-conversion voltage controlled oscillator 454 . The up-conversion voltage controlled oscillator 454 is connected to an amplifier 464 in the output buffer module 460 .

Here, the mixing module 453 is connected between the low-pass filter module 450 and the output buffer module 460 . The frequency mixing module 453 mixes the zero-IF signals ZIF1 and ZIF2 generated by the low-pass filter module 450 according to the received up-conversion signal OSC2 to generate an intermediate frequency signal IF. That is to say, the newly added frequency mixing module 453 in this embodiment is required when the radio frequency signal receiving device 400 is set to generate the intermediate frequency output signal IFOUT. And at this time, the switch 430 will transmit the output of the mixing module 420 to the low-pass filter module 450 through the first channel according to the selection signal SEL, and then transmit it to the low-pass filters 451 and 452 respectively (at this time, the switch SW1 status is disconnected).

The up-conversion signal OSC2 is generated by the up-conversion voltage controlled oscillator 454 . Similar to the down-frequency voltage controlled oscillator in the previous embodiment, the up-frequency signal OSC2 can also be adjusted by adjusting the voltage received by the up-frequency voltage control oscillator 454 . This adjustment action can be implemented by hardware or software.

The amplifier 464 is built in the output buffer module 460 to receive and amplify the intermediate frequency signal IF, and then generate the intermediate frequency output signal IFOUT.

In addition, when the amplifier 464 generates the intermediate frequency output signal IFOUT, the amplifiers 462 and 463 receive the zero intermediate frequency signals ZIF1 and ZIF2 at the same time. Therefore, the amplifiers 462, 463 can also simultaneously generate the zero-IF output signals ZIFOUT1, ZIFOUT2.

To sum up, the present invention proposes a radio frequency signal receiving device capable of outputting low-IF signals or zero-IF signals, or even outputting IF signals. In this way, different requirements can be achieved only by constructing a set of circuits. Effectively save the circuit area and cost on the chip.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that: it still Modifications or equivalent replacements can be made to the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims (14)

1. a radiofrequency signal receiving system is characterized in that, comprising:

One first polyphase filters receives a radio-frequency input signals, and radiofrequency signal after most filtering of generation according to this;

One first mixing module connects described first polyphase filters, carries out mixing in order to radiofrequency signal after foundation one frequency reducing signal and the described filtering, and then produces most frequency reducing radiofrequency signals;

One switches switch, receives described frequency reducing radiofrequency signal, according to a selection signal, transmits described frequency reducing radiofrequency signal to a first passage or a second channel;

One second polyphase filters connects described diverter switch, and receives the described frequency reducing radiofrequency signal that is sent to by described second channel to carry out filtering; And

One low pass filter module, connect described second polyphase filters and described diverter switch, described frequency reducing radiofrequency signal after accepting filter or the described frequency reducing radiofrequency signal that reached by described first passage to be carrying out low-pass filtering, and then produce a Low Medium Frequency signal or a zero intermediate frequency signals.

2. radiofrequency signal receiving system according to claim 1 is characterized in that, wherein also comprises:

One output buffering module connects described low pass filter module, receives and amplifies described Low Medium Frequency signal or described zero intermediate frequency signals, and produce a Low Medium Frequency output signal or a zero intermediate frequency output signal.

3. radiofrequency signal receiving system according to claim 2 is characterized in that, wherein also comprises:

One second mixing module, be connected between described low pass filter module and described output buffering module, when described low pass filter module produced described zero intermediate frequency signals, the described second mixing module carried out mixing and then produces an intermediate-freuqncy signal according to a up-conversion signal and described zero intermediate frequency signals.

4. radiofrequency signal receiving system according to claim 3 is characterized in that, wherein also comprises:

One raising frequency voltage control oscillator connects the described second mixing module, in order to produce described up-conversion signal.

5. radiofrequency signal receiving system according to claim 3 is characterized in that, wherein said output buffering module also receives and amplifies described intermediate-freuqncy signal, to produce an intermediate frequency output signal.

6. radiofrequency signal receiving system according to claim 5 is characterized in that, wherein said output buffering module comprises:

Most amplifiers connect described low pass filter module, in order to receive and to amplify described Low Medium Frequency signal or described zero intermediate frequency signals and described intermediate-freuqncy signal.

7. radiofrequency signal receiving system according to claim 6 is characterized in that, wherein each described amplifier is a programmable-gain amplifier.

8. radiofrequency signal receiving system according to claim 1 is characterized in that, wherein also comprises:

One frequency reducing voltage control oscillator connects the described first mixing module, in order to produce described frequency reducing signal.

9. radiofrequency signal receiving system according to claim 1 is characterized in that, wherein said low pass filter module comprises:

One first low pass filter connects described diverter switch and described second polyphase filters, receive the output of described second polyphase filters or the part of the described frequency reducing radiofrequency signal that reaches by described first passage to carry out low-pass filtering;

One second low pass filter connects described first low pass filter and described diverter switch, and the output that receives the another part of the described frequency reducing radiofrequency signal that is reached by described first passage or described first low pass filter is to carry out filtering; And

One switch is connected between described first low pass filter and described second low pass filter, in order to conducting or close being connected between described first low pass filter and described second low pass filter.

10. radiofrequency signal receiving system according to claim 9, it is characterized in that, wherein when described first low pass filter receive the output of described second polyphase filters and output that described second low pass filter receives described first low pass filter when carrying out filtering, described low pass filter module produces described Low Medium Frequency signal.

11. radiofrequency signal receiving system according to claim 9, it is characterized in that, wherein when described first low pass filter receive the part of the described frequency reducing radiofrequency signal that reaches by described first passage and another part that described second low pass filter receives the described frequency reducing radiofrequency signal that is reached by described first passage when carrying out filtering, described low pass filter module produces described zero intermediate frequency signals.

12. radiofrequency signal receiving system according to claim 1 is characterized in that, wherein said first polyphase filters is the radio frequency polyphase filters.

13. radiofrequency signal receiving system according to claim 1 is characterized in that, wherein said second polyphase filters is the intermediate frequency polyphase filters.

14. radiofrequency signal receiving system according to claim 1 is characterized in that, wherein also comprises:

One low noise amplifier is connected described first polyphase filters and receives on the path of described radio-frequency input signals.

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