TWI420832B - Dual-band receiver architecture and electronic device using same - Google Patents

Description

Dual band receiving system and electronic device thereof

The present invention relates to a dual band receiving system and an electronic device therefor.

At present, the public wireless communication network includes various frequency bands such as GSM, CDMA, PHS, and WCDMA. Different communication networks have different coverage and service content. In order to meet the user's service requirements for different communication networks, many mobile phones have dual-band dual-mode modules or multi-frequency multi-mode modules for switching between different communication networks. Currently, dual-band dual-mode modules generally have two implementations. One way is to use the same circuit architecture to divide the signals of two different frequency bands, that is, when the mobile phone is in the first frequency band mode, the circuit architecture processes the frequency band signals corresponding to the first frequency band mode, and when the action When the phone is in the second band mode, the circuit architecture processes the band signal corresponding to the second band mode. The disadvantage of this method is that the circuit architecture cannot simultaneously process signals of two different frequency bands, that is, the user cannot use two different communication networks at the same time. Another way is to set two separate circuit architectures for the two different frequency bands, respectively for processing the signals of the two frequency bands. The disadvantage of this method is that due to the use of two independent circuit architectures, the circuit components are more, and the power consumption and cost are higher.

In view of this, it is necessary to provide a way to simultaneously handle two different frequencies in the same circuit. A dual band receiving system with signals and an electronic device for its application.

A dual band receiving system includes a dual frequency antenna, a dual frequency filter, a dual frequency low noise amplifier and a dual frequency simultaneous direct frequency down module. The dual-frequency antenna receives radio wave signals from the first frequency band and the second frequency band of the communication base station, and converts the radio wave signals into electrical signals of respective frequency bands and outputs the electrical signals to the dual-frequency filter. The first frequency band has a first channel f _L and the second frequency band has a second channel f _H . The frequency range of the first channel f _L and the second channel f _H is 0<f ₁ ≦f _L ≦f ₂ <f ₃ ≦f _H ≦f ₄ , and f ₃ -f ₂ >f ₂ -f ₁ , f ₃ -f ₂ >f ₄ -f ₃ . The dual frequency filter filters an electrical signal output by the dual frequency antenna to filter out electrical signals outside the first frequency band and the second frequency band. The dual-frequency low-noise amplifier amplifies the electrical signal filtered by the dual-frequency filter and outputs the signal to the dual-frequency simultaneous direct-down module. The dual-frequency simultaneous direct down-conversion module includes a dual-frequency synthesizer and a first frequency-down circuit and a second frequency-down circuit coupled to the dual-frequency frequency synthesizer, respectively. The dual frequency synthesizer simultaneously generates a signal having a first local oscillator frequency f _O1 and a signal having a second local oscillator frequency f _O2 , where f ₁ ≦f _O1 ≦f ₂ <f ₃ ≦f _O2 ≦f ₄ . The dual frequency synthesizer outputs a signal having the first local oscillation frequency f _O1 and a signal having a second local oscillation frequency f _O2 to the first frequency reduction circuit and the second frequency reduction circuit, respectively. The first frequency down circuit and the second frequency down circuit receive electrical signals from the first channel f _L and the second channel f _H of the dual frequency low noise amplifier, and according to formulas (1) and (2), respectively And the equations (3), (4) down-convert the electrical signals of the first channel f _L and the second channel f _H , f _{L 1} =| f _L - f _{O 1} | (1), f _{H 1} = | f _H - f _{O 1} | (2), f _{L 2} =| f _L - f _{O 2} | (3), f _{H 2} =| f _H - f _{O 2} | (4).

Wherein, F _L1 and f _H1 represent channels corresponding to the electrical signals of the first channel f _L and the second channel f _H in the first frequency down circuit after the frequency reduction, and f _L2 and f _H2 represent the second drop. The electrical signals of the first channel f _L and the second channel f _{H in} the frequency circuit are corresponding to the channel after the frequency reduction. The first frequency reduction circuit filters out the electrical signal of the f _H1 channel obtained after the frequency reduction, and outputs the electrical signal of the f _L1 channel, and the second frequency reduction circuit reduces the frequency of the f _L2 channel. The signal is filtered out and the electrical signal of the f _H2 channel is output.

An electronic device applying a dual band receiving system includes a dual band receiving system, a digital signal processor and a human machine interface. The dual band receiving system is configured to receive radio wave signals from a first frequency band and a second frequency band of a communication base station, and convert the radio wave signals into electrical signals of respective frequency bands. The first frequency band has a first channel f _L and the second frequency band has a second channel f _H . The dual-band receiving system down- _converts the electrical signals of the first channel f _L and the second channel f _H to the f _L1 channel and the f _H2 channel, respectively, and outputs the signals to the digital signal processor. The digital signal processor is configured to process the electrical signals of the f _L1 channel and the f _H2 channel and output the signal to the human machine interface. The human machine interface is configured to convert the electrical signal processed by the digital signal processor into information that can be received by the user and output.

Compared with the prior art, the dual band receiving system and the electronic device of the same according to the two local oscillator frequencies output by the dual frequency synthesizer are respectively located on the first channel and the first frequency band and the second frequency band respectively. The electrical signal of the second channel is simultaneously down-converted, and then filtered to obtain an electrical signal corresponding to the first channel and the second channel after being down-converted and transmitted. The electronic device can simultaneously process electrical signals of two different frequency bands in the same circuit.

1‧‧‧Dual Band Receiving System

10‧‧‧Double frequency antenna

12‧‧‧Double frequency filter

14‧‧‧Double Frequency Low Noise Amplifier

16‧‧‧Double-frequency simultaneous direct down-conversion module

160‧‧‧Double Frequency Synthesizer

1600‧‧‧Double frequency voltage controlled oscillator

161‧‧‧The first frequency reduction circuit

162‧‧‧Second frequency reduction circuit

163‧‧‧First in-phase channel

1630‧‧‧First Mixer

1632‧‧‧First Variable Gain Amplifier

1634‧‧‧First low pass filter

165‧‧‧First orthogonal channel

1650‧‧‧Second mixer

2‧‧‧Electronic devices

3‧‧‧Digital Signal Processor

4‧‧‧Human Machine Interface

5‧‧‧Signal launch system

FIG. 1 is a structural diagram of a dual band receiving system according to an embodiment of the present invention.

2 is a schematic diagram showing the working principle of the first frequency down circuit of the dual band receiving system of FIG. 1.

3 is a schematic diagram showing the working principle of the second frequency down circuit of the dual band receiving system of FIG. 1.

4 is a functional block diagram of an electronic device to which the dual band receiving system of FIG. 1 is applied.

The technical solution will be further described in detail below with reference to the accompanying drawings and embodiments.

FIG. 1 shows a dual band receiving system 1 according to an embodiment of the present invention. The dual band receiving system 1 includes a dual frequency antenna 10, a dual frequency filter 12, a dual frequency low noise amplifier 14 and a dual frequency simultaneous direct frequency down module 16 in sequence.

The dual-band antenna 10 receives radio wave signals from a first frequency band and a second frequency band of a communication base station (not shown), converts the radio wave signals into electrical signals of respective frequency bands, and outputs the signals to the dual frequency. Filter 12. The first frequency band has a first channel f _L , and the frequency range of the first channel f _L is 0<f ₁ ≦f _L ≦f ₂ . The second frequency band has a second channel f _H , and the second channel f _{H has} a frequency range of f ₃ ≦f _H ≦f ₄ . Wherein f ₂ < f ₃ and f ₃ -f ₂ > f ₂ -f ₁ , f ₃ -f ₂ > f ₄ -f ₃ . Preferably, the first frequency band and the second frequency band are both radio frequencies.

The dual frequency filter 12 is configured to filter an electrical signal output by the dual frequency antenna 10 to filter out electrical signals outside the first frequency band and the second frequency band.

The dual-frequency low noise amplifier (LNA) 14 is configured to amplify the electrical signal obtained by filtering the dual-frequency filter 12 and output the signal to the dual-frequency simultaneous direct-down module 16 .

The dual-frequency simultaneous direct down-conversion module 16 includes a dual-frequency synthesizer 160 and a first frequency-down circuit 161 and a second frequency-down circuit coupled to the dual-frequency synthesizer 160, respectively. 162.

The dual frequency synthesizer 160 includes a dual voltage controlled oscillator 1600 (Voltage Controlled Oscillator, VCO). The dual-frequency voltage controlled oscillator 1600 can simultaneously generate a first local oscillator frequency f _O1 and a second local oscillator frequency f _O2 , where f ₁ ≦f _O1 ≦f ₂ <f ₃ ≦f _O2 ≦f ₄ . Preferably, f _{O 1} =( f ₁ + f ₂ )/2, f _{O 2} =( f ₃ + f ₄ )/2.

The dual frequency synthesizer 160 generates a first inphase signal I ₁ (In-Phase) having a first local oscillator frequency f _O1 and a first quadrature signal Q ₁ (Quardrature) and outputs the first down frequency to the first down frequency The circuit 161, and generates a second in-phase signal I ₂ and a second quadrature signal Q ₂ having a second local oscillation frequency f _O2 and outputs the same to the second down-conversion circuit 162.

The first frequency down circuit 161 is configured to receive an electrical signal from the dual frequency low noise amplifier 14 and to downconvert, amplify, filter and output the electrical signal. The first frequency down circuit 161 includes a first in-phase channel 163 for transmitting an in-phase signal and a first orthogonal channel 165 for transmitting a quadrature signal and in parallel with the first in-phase channel 163.

The first in-phase channel 163 includes a first mixer (Mixer) 1630, a first variable gain amplifier (VGA) 1632, and a first low-pass filter (Low-pass Filter). LPF) 1634. The first mixer 1630 is connected to the dual-frequency low noise amplifier 14 and the dual-frequency synthesizer 160, and receives the electrical signal from the dual-frequency low-noise amplifier 14 and the first from the dual-frequency synthesizer 160. In-phase signal I ₁ . Referring to FIG. 2, the first mixer 1630 down-converts the electrical signals of the first channel f _L and the second channel f _H according to formulas (1) and (2), respectively: f _{L 1} =| f _L - f _{O 1} | (1), f _{H 1} =| f _H - f _{O 1} | (2).

Wherein, f _L1 and f _H1 represent channels corresponding to the electrical signals of the first channel f _L and the second channel f _H after frequency reduction. Combining the formulas (1) and (2) and the conditions f ₁ ≦f _O1 ≦f ₂ and f ₃ -f ₂ >f ₂ -f ₁ , f _L1 <f _H1 . The electrical signal from the dual frequency low noise amplifier 14 becomes an in-phase signal after being modulated by the first in-phase signal I1 in the first mixer 1630. The first variable gain amplifier 1632 performs gain amplification on a signal output by the first mixer 1630. The first low pass filter 1634 filters the signal amplified by the first variable gain amplifier 1632 so that the signal of the f _L1 channel can pass through the first low pass filter 1634, and the signal of the f _H1 channel Then it is filtered out. Preferably, the f _L1 channel is located in the passband of the first low pass filter 1634, and the f _H1 channel is located in the stop band of the first low pass filter 1634, so the power of the f _L1 channel The signal can pass through the first low pass filter 1634, and the electrical signal of the f _H1 channel cannot pass.

The first orthogonal channel 165 is different from the first in-phase channel 163 in that the first orthogonal channel 165 includes a second mixer 1650, and the second mixer 1650 receives the The first quadrature signal Q _{1 of the} dual frequency synthesizer 160 is used to downconvert and modulate the signal from the dual frequency low noise amplifier 14 into a quadrature signal.

Referring to FIG. 3, the second frequency down circuit 162 is different from the first frequency down circuit 161 in that the second frequency down circuit 162 receives an electrical signal from the dual frequency low noise amplifier 14. And a second in-phase signal I ₂ and a second quadrature signal Q ₂ from the dual frequency synthesizer 160 having a second local oscillator frequency f _O2 and from the above according to equations (3) and (4) The electrical signals of the dual-frequency low-noise amplifier 14 are respectively down-converted, that is, f _{L 2} =| f _L - f _{O 2} | (3), f _{H 2} =| f _H - f _{O 2} | (4).

Wherein, f _L2 and f _H2 respectively represent channels corresponding to the electrical signals of the first channel f _L and the second channel f _H after frequency reduction. Combining the formulas (3) and (4) and the conditions f ₃ ≦f _O2 ≦f ₄ and f ₃ -f ₂ >f ₄ -f ₃ , f _L2 >f _H2 . The signal of the f _L2 channel is filtered by the low pass filter in the second down converter circuit 162, and the signal of the f _H2 channel is amplified and outputted in the second down frequency circuit 162.

FIG. 4 shows an electronic device 2 to which the dual band receiving system 1 is applied. In the present embodiment, the electronic device 2 is a mobile phone. The electronic device 2 includes a dual-band receiving system 1, a digital signal processor 3, a human-machine interface 4, and a signal transmitting system 5.

The dual band receiving system 1 is configured to receive radio wave signals from a first frequency band and a second frequency band of a communication base station (not shown), and convert the radio wave signals into electrical signals of respective frequency bands. The first frequency band has a first channel f _L and the second frequency band has a second channel f _H . The dual band receiving system 1 down- _converts the electrical signals of the first channel f _L and the second channel f _H to the f _L1 channel and the f _H2 channel, respectively, and outputs the signals to the digital signal processor 3 .

The digital signal processor 3 is configured to process the electrical signals of the f _L1 channel and the f _H2 channel and output the signals to the human interface 4, and process the electrical signals from the human interface 4 to output The signal transmission system 5 is described. The digital signal processor 3 can simultaneously output the electrical signals of the f _L1 channel and the f _H2 channel, and can also output an electrical signal of one of the channels according to the user's selection.

The human interface 4 is configured to convert the electrical signal processed by the digital signal processor 3 into information receivable by the user and output the information to the user, and input an electrical signal to the digital signal according to the operation of the user. Processor 3. The human interface 4 includes a display, a microphone, and an earpiece.

The signal transmitting system 5 is configured to convert the electrical signal input by the human-machine interface 4 and processed by the digital signal processor 3 into a radio wave signal, and transmit the radio wave signal to the communication base station.

Compared with the prior art, the dual band receiving system and the electronic device of the same according to the two local oscillator frequencies output by the dual frequency synthesizer are respectively located on the first channel and the first frequency band and the second frequency band respectively. The electrical signal of the second channel is simultaneously down-converted, and then filtered to obtain an electrical signal corresponding to the first channel and the second channel after being down-converted and output, so that the electronic device can simultaneously process two different frequency bands in the same circuit. Electrical signal.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and cannot be limited thereto. The scope of the patent application for this case. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

1‧‧‧Dual Band Receiving System

10‧‧‧Double frequency antenna

12‧‧‧Double frequency filter

14‧‧‧Double Frequency Low Noise Amplifier

16‧‧‧Double-frequency simultaneous direct down-conversion module

160‧‧‧Double Frequency Synthesizer

1600‧‧‧Double frequency voltage controlled oscillator

161‧‧‧The first frequency reduction circuit

162‧‧‧Second frequency reduction circuit

163‧‧‧First in-phase channel

1630‧‧‧First Mixer

1632‧‧‧First Variable Gain Amplifier

1634‧‧‧First low pass filter

165‧‧‧First orthogonal channel

1650‧‧‧Second mixer

Claims (8)

A dual-band receiving system includes a dual-frequency antenna, a dual-frequency filter, a dual-frequency low-noise amplifier, and a dual-frequency simultaneous direct-down module sequentially coupled to the communication base station. a radio wave signal of the first frequency band and the second frequency band, respectively converting the radio wave signal into an electrical signal of a corresponding frequency band and outputting to the dual frequency filter, wherein the first frequency band has a first channel f _L , The second frequency band has a second channel f _H , and the frequency range of the first channel f _L and the second channel f _H is 0<f ₁ ≦f _L ≦f ₂ <f ₃ ≦f _H ≦f ₄ And f ₃ -f ₂ > f ₂ -f ₁ , f ₃ -f ₂ > f ₄ -f ₃ , wherein f ₁ and f ₂ are lower and upper limits of the first frequency band, and f ₃ and f ₄ are second a lower limit and an upper limit of the frequency band; the dual frequency filter filters an electrical signal output by the dual frequency antenna to filter out electrical signals outside the first frequency band and the second frequency band, the dual frequency low noise An amplifier amplifies the electrical signal filtered by the dual-frequency filter and outputs the same to the dual-frequency simultaneous direct-down module, wherein the dual-frequency direct drop simultaneously The frequency module includes a dual frequency synthesizer and a first frequency down circuit and a second frequency down circuit respectively coupled to the dual frequency frequency synthesizer, the dual frequency frequency synthesizer simultaneously generating a first copy a signal of a frequency f _o1 and a signal having a second local oscillator frequency f _O2 , wherein f ₁ ≦f _O1 ≦f ₂ <f ₃ ≦f _O2 ≦f ₄ , the dual-frequency synthesizer will have the a signal of the local oscillation frequency f _O1 and a signal having the second local oscillation frequency f _O2 are respectively output to the first frequency reduction circuit and the second frequency reduction circuit, and the first frequency reduction circuit and the second frequency reduction circuit receive An electrical signal from the first channel f _L and the second channel f _H of the dual-frequency low noise amplifier, and the first according to formulas (1), (2) and formulas (3), (4), respectively The electrical signals of the channel f _L and the second channel f _H are down-converted, f _{L 1} =| f _L - f _{O 1} | (1), f _{H 1} =| f _H - f _{O 1} | (2), f _{L 2} =| f _L - f _{O 2} | (3), f _{H 2} =| f _H - f _{O 2} | (4), where f _L1 , f _H1 represent the first channel in the first down-converting circuit f _L and the electric signal of the second channel f _H corresponding to the channel after frequency reduction, f _L2 , f _H2 Representing the channel corresponding to the first channel f _L and the second channel f _H of the second down-converting circuit after the frequency reduction, the first frequency-down circuit will reduce the frequency of the f _H1 channel The signal is filtered out, and the electrical signal of the f _L1 channel is output, and the second frequency reducing circuit filters out the electrical signal of the f _L2 channel obtained by the frequency reduction, and outputs the electrical signal of the f _H2 channel; The down-converting circuit and the second down-converting circuit each include an in-phase channel and an orthogonal channel, and the dual-frequency synthesizer outputs an in- _phase signal and a quadrature signal having a first local oscillator frequency f _O1 to the first An in-phase channel and an orthogonal channel of the down-converting circuit, and an in-phase channel and an orthogonal channel respectively outputting the in-phase signal and the quadrature signal having the second local oscillation frequency f _O2 to the second frequency-down circuit, The first down-converting circuit and the in-phase channel and the quadrature channel of the second down-converting circuit respectively generate power from the dual-frequency low-noise amplifier according to the in-phase signal and the quadrature signal provided by the dual-frequency synthesizer The signal is modulated into an in-phase signal and a quadrature signal, and according to formulas (1), (2) and (3), (4) said first electrical signal and the second channel f _L fH of the down-channel. The dual band receiving system of claim 1, wherein the first frequency down circuit and the second frequency down circuit each comprise at least one mixer, the mixer and the dual frequency low noise amplifier and a dual frequency synthesizer is connected, and the mixer of the first frequency down circuit and the second frequency down circuit respectively sets the first channel f according to formulas (1), (2) and formulas (3), (4) The electrical signals of _L and the second channel f _H are down-converted. The dual band receiving system of claim 1, wherein the first frequency down circuit and the second frequency down circuit each comprise at least one low pass filter, and the f _L1 channel and the fH2 channel are located in the low pass filter Within the passband of the device, the f _H1 channel and the f _L2 channel are located within the stop band of the low pass filter. The dual band receiving system according to claim 1, wherein the first local oscillation frequency f _O1 and the second local oscillation frequency f _O2 satisfy the following condition: f _{O 1} = ( f ₁ + f ₂ )/2, f _{O 2} = ( f ₃ + f ₄ )/2. The dual band receiving system according to claim 1, wherein the first down-converting circuit and the in-phase channel and the orthogonal channel of the second down-converting circuit are connected in parallel with each other. An electronic device using the dual band receiving system of claim 1, comprising a dual band receiving system, a digital signal processor and a human machine interface; the dual band receiving system is configured to receive from a communication base station a radio wave signal of the first frequency band and the second frequency band, respectively converting the radio wave signal into an electrical signal of a corresponding frequency band, wherein the first frequency band has a first channel f _L and the second frequency band has a second Channel f _H , the dual-band receiving system down- _converts the electrical signals of the first channel f _L and the second channel f _H to the f _L1 channel and the f _H2 channel, respectively, and outputs the digital signal to the digital signal processor; The signal processor is configured to process the electrical signals of the f _L1 channel and the f _H2 channel and output the signal to the human machine interface; the human machine interface is configured to convert the electrical signal processed by the digital signal processor into a user Information that can be received and output. The electronic device of claim 6, wherein the electronic device further comprises a signal transmitting system, the human machine interface inputs an electrical signal to the digital signal processor according to a user operation, and the digital signal processing The device processes the electrical signal from the human-machine interface and outputs the signal to the signal transmitting system, and the signal transmitting system converts the electrical signal input by the human-machine interface and processed by the digital signal processor into a wireless signal. The radio wave signal is transmitted to the communication base station. The electronic device of claim 6, wherein the digital signal processor outputs an electrical signal of at least one of the f _L1 channel and the f _H2 channel obtained by the down-conversion to the human-machine according to a user's selection. interface.