A 5G dual-band up-mixer and terminal with amplification and mixing function switching

Abstract

The present invention belongs to the technical field of 5G millimeter wave communication, and discloses a 5G dual-band mixer and terminal with amplification and mixing function switching, wherein a first double-balanced active mixer and a second double-balanced active mixer are connected in series, and both ends of the first double-balanced active mixer are respectively connected to a first transformer and a second transformer, and both ends of the second double-balanced active mixer are respectively connected to a second transformer and a third transformer; the first double-balanced active mixer is provided with a first MOS tube and a fourth transformer connected to the first MOS tube; the second double-balanced active mixer is provided with a second MOS tube and a fifth transformer connected to the second MOS tube. The present invention connects two double-balanced mixers in series, and the mixer of the latter stage can switch to an amplifier function by controlling the bias voltage and the AC signal switch, so that the entire mixer can perform one mixing or two mixing, corresponding to the radio frequency signals of the two frequency bands, respectively, so that dual-band mixing can be realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of 5G millimeter wave communications, and in particular relates to a 5G dual-band mixer and terminal with switching of amplification and mixing functions. Background Art

[0002] At present, the proposal and application of 5G millimeter wave technology requires RF chips to simultaneously process RF information near the two frequencies of 27GHz and 39GHz to achieve dual-band transceiver communications. For transmitter chips, it is not only necessary to be able to amplify signals in two frequency bands at the same time, but also to adopt a suitable frequency conversion method so that the mixing result of the intermediate frequency signal and the local oscillator signal can cover two RF bands.

[0003] Taking China's 5G millimeter wave frequency bands of 24.25-27.5GHz and 37.5-42.5GHz as an example, for the frequency conversion method of a single-frequency local oscillator, if the local oscillator frequency is less than 24.25GHz, then after dual-band down-conversion, the upper limit of the intermediate frequency will exceed 42.5GHz-24.25GHz=18.25GHz. If the intermediate frequency is too high, the meaning of down-conversion will be lost and the design difficulty of the intermediate frequency link will be increased. Therefore, the common up-conversion scheme adopts the method of changing the local oscillator frequency to change the local oscillator frequency when the intermediate frequency is low to cover two different frequency bands. The intermediate frequency signal takes 4-6GHz, and the local oscillator frequency is converted to 20.25-36.5GHz. The basic structure of the circuit adopts the common Gilbert-type active mixer or passive ring mixer. Although dual-band up-conversion can be achieved, there are still many problems. The corresponding disadvantages are as follows:

[0004] (1) The local oscillator link bandwidth is under great pressure. Although the intermediate frequency of this solution is only 4-6 GHz, the local oscillator needs to be in the frequency band range of 20.25-36.5 GHz, and the relative bandwidth is about 57%. This will put a lot of pressure on the local oscillator link bandwidth design, especially the frequency multiplier module, which is very difficult to design.

[0005] (2) The sideband signal will fall within the RF band. Since the intermediate frequency bandwidth is relatively narrow, the coverage of the RF band is mainly achieved by changing the local oscillator frequency. During the local oscillator frequency change process, the sideband frequency of one local oscillator may be very close to the RF frequency of another local oscillator, or even overlap. For example, when the local oscillator frequency is 22GHz, it can be mixed up to obtain a 26-28GHz RF signal. When the local oscillator frequency is 32GHz, it can obtain both a 36-38GHz RF signal and a 26-28GHz sideband signal. This sideband signal will be transmitted with the transmitter and interfere with other devices that use the 26-28GHz RF band for communication.

[0006] Through the above analysis, the problems and defects of the existing technology are: in the application of 5G millimeter wave communication technology, the intermediate frequency information is mixed up to the frequency bands near 27GHz and 39GHz, which makes it difficult to reduce the bandwidth design pressure of the intermediate frequency and radio frequency links while suppressing the sideband frequency. Summary of the invention

[0007] In view of the problems existing in the prior art, the present invention provides a 5G dual-band up-mixer with switching of amplification and mixing functions.

[0008] The present invention is implemented as follows: a 5G dual-band up-mixer with amplification and mixing function switching includes:

[0009] a first double-balanced active mixer and a second double-balanced active mixer;

[0010] The first double-balanced active mixer and the second double-balanced active mixer are connected in series, two ends of the first double-balanced active mixer are connected to the first transformer and the second transformer respectively, and two ends of the second double-balanced active mixer are connected to the second transformer and the third transformer respectively;

[0011] The first double-balanced active mixer is provided with a first MOS transistor and a fourth transformer connected to the first MOS transistor;

[0012] The second double-balanced active mixer is provided with a second MOS transistor and a fifth transformer connected to the second MOS transistor.

[0013] Further, one end of the primary coil of the first transformer is connected to the IF signal port, and the other end is grounded; one end of the secondary coil is connected to the source of the first MOS tubes M1 and M2, and the other end is connected to the source of the first MOS tubes M3 and M4; the center tap of the secondary coil is grounded;

[0014] Furthermore, the gates of the first MOS transistors M1 and M4 are connected to the LO1+ signal terminal, and the gates of the first MOS transistors M2 and M3 are connected to the LO1- signal terminal; one end of the primary coil of the fourth transformer is connected to the LO1+ signal terminal, and the other end is connected to the LO1- signal terminal, one end of the secondary coil is connected to the LO signal port, and the other end is grounded.

[0015] Furthermore, a resistor R1 is connected between the LO1-signal terminal and the bias voltage Vb1, and a resistor R2 is connected between the LO1+signal terminal and the bias voltage Vb1.

[0016] Further, one end of the primary coil of the second transformer is connected to the drains of the first MOS transistors M1 and M3, the other end is connected to the drains of the first MOS transistors M2 and M4, and the center tap is connected to the power supply Vdd;

[0017] One end of the secondary coil of the second transformer is connected to the sources of the second MOS transistors M5 and M6, the other end is connected to the sources of the second MOS transistors M7 and M8, and the center tap is grounded.

[0018] Furthermore, the gates of the second MOS transistors M5 and M8 are connected to the LO2+ signal terminal, and the gates of the second MOS transistors M6 and M7 are connected to the LO2- signal terminal;

[0019] One end of the primary coil of the fifth transformer is connected in series with switch S1 and capacitor C1 to the LO2- signal terminal, and the other end is connected in series with switch S2 and capacitor C2 to the LO2+ signal terminal. One end of the secondary coil is connected to the LO signal terminal, and the other end is grounded.

[0020] Furthermore, a resistor R3 is connected between the LO2-signal terminal and the bias voltage Vb2, and a resistor R4 is connected between the LO2+signal terminal and the bias voltage Vb3.

[0021] Another object of the present invention is to provide a wireless communication terminal, which is equipped with the 5G dual-band mixer with amplification and mixing function switching.

[0022] Another object of the present invention is to provide a 5G millimeter wave communication terminal, which is equipped with the 5G dual-band mixer with amplification and mixing function switching.

[0023] In combination with the above technical solutions and the technical problems solved, please analyze the advantages and positive effects of the technical solutions to be protected by the present invention from the following aspects:

[0024] First, in view of the technical problems existing in the above-mentioned prior art and the difficulty of solving the problems, the technical solutions to be protected by the present invention and the results and data during the research and development process are closely combined to analyze in detail and deeply how the technical solutions of the present invention solve the technical problems, and some creative technical effects brought about after solving the problems. The specific description is as follows:

[0025] The present invention connects two modules in series, the first module is a mixer, and the second module can switch between the two functional modes of the mixer and the amplifier by controlling the bias and signal switch, thereby switching the intermediate frequency and the local oscillator frequency for one mixing and two mixing, realizing dual-band up-mixing and covering two millimeter wave frequency bands.

[0026] The present invention adopts a two-stage common-gate structure, which has a higher gain than a traditional passive mixer, helps to improve link performance, and reduces the gain pressure of the subsequent amplifier.

[0027] The sideband interference frequencies generated by the up-mixer of the present invention are all out-of-band and can be filtered out by matching filtering, so they will not interfere with the operation of other communication devices.

[0028] The present invention improves the traditional dual-band frequency conversion method by connecting two double-balanced mixers in series. The mixer at the rear stage can be switched to an amplifier function by controlling the bias voltage and the AC signal switch, so that the entire mixer can perform one or two mixing operations, corresponding to the radio frequency signals of the two frequency bands, respectively, thereby achieving dual-band up-mixing. The present invention also significantly reduces the demand for the local oscillator bandwidth of the dual-band millimeter wave system, so it will not bring greater design pressure to the intermediate frequency link and the local oscillator link. The sideband frequencies generated by the present invention are all out-of-band and can be suppressed by matched filtering, so they will not cause interference to other devices.

[0029] Second, considering the technical solution as a whole or from the perspective of the product, the technical effects and advantages of the technical solution to be protected by the present invention are described in detail as follows:

[0030] The 5G dual-band up-mixer with amplification and mixing function switching provided by the present invention can achieve up-mixing to cover two millimeter wave bands of my country's 5G communication when the intermediate frequency is 4-6GHz and the local oscillator frequency is 20-24GHz, reducing the design pressure of the local oscillator link and the intermediate frequency link. In addition, the sideband frequencies generated by this mixer are all out of band and can be suppressed by matching filtering, so it will not cause interference to other communication equipment.

[0031] Third, as auxiliary evidence of the creativity of the claims of the present invention, it is also reflected in the following important aspects: the expected benefits and commercial value of the technical solution of the present invention after transformation are: using simpler wiring and lower power consumption to achieve dual-band up-conversion of 5G millimeter waves, making full use of 5G spectrum resources while saving chip area and chip power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a structural principle diagram of a 5G dual-band up-mixer with amplification and mixing function switching provided by an embodiment of the present invention;

[0033] Figure 2 It is a principle diagram of the working states of M5 to M8 provided by an embodiment of the present invention in both mixer and amplifier functions;

[0034] In the figure: 1, first transformer; 2, second transformer; 3, third transformer; 4, fourth transformer; 5, fifth transformer. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0036] 1. Explanatory Examples In order to enable those skilled in the art to fully understand how to implement the present invention, this section provides an illustrative example that expands and describes the technical solution of the claims.

[0037] like Figure 1 As shown, the core part of the 5G dual-band mixer with amplification and mixing function switching provided by the embodiment of the present invention is two series-connected double-balanced active mixers, which transmit signals and impedance matching through transformer coupling, and introduce a signal control part at the local oscillator end. While providing a bias voltage, the function switching of the mixer and the amplifier is realized to achieve dual-band mixing.

[0038] One end of the primary coil of the first transformer 1 is connected to the IF signal port and the other end is grounded; one end of the secondary coil is connected to the source of MOS tubes M1 and M2, and one end is connected to the source of MOS tubes M3 and M4, and the center tap of the secondary coil is grounded; the gates of MOS tubes M1 and M4 are connected to the LO1+ signal, and the gates of MOS tubes M2 and M3 are connected to the LO1- signal; one end of the primary coil of the second transformer is connected to the drains of M1 and M3, and one end is connected to the drains of M2 and M4, and the center tap is connected to the power supply Vdd; one end of the secondary coil is connected to the source of MOS tubes M5 and M6, and one end is connected to the source of MOS tubes M7 and M8, and the center tap is grounded; the gates of MOS tubes M5 and M8 are connected to the LO2+ signal, and the gates of MOS tubes M6 and M7 are connected to the LO2- signal;

[0039] One end of the primary coil of the third transformer 3 is connected to the drains of M5 and M7, the other end is connected to the drains of M6 and M8, the center tap is connected to the power supply Vdd, and the two ends of the secondary coil are respectively connected to the two differential ports RF+ and RF- of the radio frequency signal;

[0040] One end of the primary coil of the fourth transformer 4 is connected to LO1+, the other end is connected to LO1-, one end of the secondary coil is connected to the LO signal port, and one end is grounded;

[0041] One end of the primary coil of the fifth transformer 5 is connected in series with switch S1, capacitor C1 to LO2-, and the other end is connected in series with switch S2, capacitor C2 to LO2+. One end of the secondary coil is connected to the LO signal end, and the other end is grounded. The two ends of the resistor R1 are respectively connected to the bias voltage Vb1 and LO1-, the two ends of the resistor R2 are respectively connected to the bias voltage Vb1 and LO1+, the two ends of the resistor R3 are respectively connected to the bias voltage Vb2 and LO2-, and the two ends of the resistor R4 are respectively connected to the bias voltage Vb3 and LO2+.

[0042] M1~M4 constitute the core switch tube of the first mixer, which is a double-balanced active mixer. The intermediate frequency signal is coupled from the first transformer into the source of M1~M4. The bias voltage Vb1 biases M1~M4 near the threshold voltage through the resistors R1 and R2 that isolate the AC. The local oscillator signal is coupled from the fourth transformer to LO1+ and LO1-, and then connected to the gate of M1~M4, controlling M1~M4 to turn on and off in turn to achieve mixing. The sum of the angular frequencies of the output signals of the first mixer is ω IF1 =ω LO +ω IF and ω IF2 =ω LO -ω IF .

[0043] M5~M8 can have two functional modes, mixer mode and amplifier mode. When M5~M8 works in mixer mode, switches S1 and S2 are closed, and M5~M8 form the core switch tube of the second mixer. The structure is a double-balanced active mixer, such as Figure 2 As shown. After a mixing, the IF1 and IF2 signals are coupled from the second transformer into the source of M5-M8. The bias voltages Vb2 and Vb3 bias M5-M8 near the threshold voltage through the isolated AC resistors R3 and R4, respectively. The local oscillator signal is coupled from the fifth transformer and capacitors C1 and C2 to the two differential terminals LO2+ and LO2-, respectively, and then connected to the gates of M5-M8, controlling M5-M8 to turn on and off in turn to achieve mixing, so that a higher frequency signal can be output. The angular frequency of the output signal of the second mixer is ω IF ,ω RF =ω LO +ω IF2 =2ω LO -ω IF and ω side =ω LO +ω IF1 =2ω LO +ω IF Among them, the intermediate frequency is generated by first adding a local oscillator frequency and then subtracting a local oscillator frequency because the local oscillator frequencies of the two mixings are the same.

[0044] When M5-M8 works in amplifier mode, switches S1 and S2 are turned off, so no high-power local oscillator signal enters the gate of M5-M8, Vb2 is biased at ground potential, so M6 and M7 are turned off, and Vb3 is biased at 50mV higher than the threshold voltage, so that M5 and M8 work in the state of common gate amplifier. [2] , the DC current becomes larger. At this time, this part can amplify the signal but will not change the frequency of the input signal. The part where the local oscillator frequency and the intermediate frequency are added is selected as the output RF frequency ω RF =ω IF1=ω LO +ω IF .

[0045] The second transformer 2 and the third transformer 3 realize signal coupling and matching filtering. The third transformer 3 filters out the frequency band information of 24.25-42.5 GHz in combination with the upper and lower impedances, and the second transformer 2 filters out the frequency band information of 16.5-27.5 GHz in combination with the upper and lower impedances.

[0046] When the intermediate frequency is 5 GHz, if M5 to M8 work in the mixer mode, the entire up-mixing is mixed twice, and the output RF frequency is 2×22 GHz-5 GHz=39 GHz. The generated sideband frequency 2×22 GHz+5 GHz=49 GHz and the intermediate frequency 5 GHz are both out of band and will be filtered out with the matched filter, so they will not interfere with the communication of other devices; if M5 to M8 work in the amplifier mode, the entire up-mixing is mixed only once, and the output RF frequency is 22 GHz+5 GHz=27 GHz. The generated sideband frequency 22 GHz-5 GHz=17 GHz is out of band and will be filtered out with the matched filter, so it will not interfere with the communication of other devices.

[0047] This method of switching between single mixing and double mixing allows the local oscillator and the intermediate frequency to correspond to the information of two different frequency bands by simply switching modes while keeping the frequencies unchanged, which greatly reduces the pressure on bandwidth design. if1 ~f if2 , the local oscillator range is f lo1 ~f lo2 When the RF end of this mixer can cover f if1 +f lo1 ~f if2 +f lo2 and 2×f lo1 -f if2 ~2×f lo2 -f if1 Two frequency bands. If the intermediate frequency signal is 4-6GHz and the local oscillator signal is 20-24GHz, the two millimeter wave frequency bands of my country's 5G communication can be covered, and the sideband frequencies generated are all out of band, which can be suppressed by matching filtering to reduce interference to other devices.

[0048] 2. Application Examples: In order to prove the creativity and technical value of the technical solution of the present invention, this section provides application examples of the technical solution of the claims on specific products or related technologies.

[0049] The present invention provides a 5G communication system equipped with a 5G dual-band up-mixer with switching of amplification and mixing functions.

[0050] 3. Evidence of the effects of the embodiments. The embodiments of the present invention have achieved some positive effects during the development or use process, and indeed have great advantages over the prior art. The following content is described in conjunction with the data, charts, etc. of the test process.

[0051] In order to cover the two frequencies of 5G millimeter waves, the traditional solution requires a local oscillator bandwidth of 20.25GHz-21.5GHz and 33.5GHz-36.5GHz, while the intermediate frequency remains unchanged at 4-6GHz. These two wide frequency bands will bring greater design pressure to the VCO and frequency multiplier components of the local oscillator link, and also introduce difficulties in matching the mixer gate. The local oscillator of the present invention only requires a signal of a frequency band of 20-24GHz to enter, thus greatly reducing the design pressure of the local oscillator link. The sideband frequencies of the traditional solution will be transmitted with the transmitter, affecting other communication equipment. The sideband frequencies of the present invention are all out of band and can be suppressed, so they will not interfere with other equipment.

[0052] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A 5G dual-band up-mixer with switching of amplification and mixing functions, characterized in that: The 5G dual-band up-mixer with switching of amplification and mixing functions comprises: a first double-balanced active mixer and a second double-balanced active mixer; The first double-balanced active mixer and the second double-balanced active mixer are connected in series, two ends of the first double-balanced active mixer are connected to the first transformer and the second transformer respectively, and two ends of the second double-balanced active mixer are connected to the second transformer and the third transformer respectively; The first double-balanced active mixer is provided with a first MOS transistor and a fourth transformer connected to the first MOS transistor; The second double-balanced active mixer is provided with a second MOS tube and a fifth transformer connected to the second MOS tube; One end of the primary coil of the first transformer is connected to the IF signal port, and the other end is grounded; one end of the secondary coil is connected to the source electrodes of the first MOS transistors M1 and M2, and the other end is connected to the source electrodes of M3 and M4 of the first MOS transistors; and the center tap of the secondary coil is grounded; The gates of the first MOS transistors M1 and M4 are connected to the LO1+ signal terminal, and the gates of the first MOS transistors M2 and M3 are connected to the LO1- signal terminal; one end of the primary coil of the fourth transformer is connected to the LO1+ signal terminal, and the other end is connected to the LO1- signal terminal, one end of the secondary coil is connected to the LO signal port, and the other end is grounded; One end of the primary coil of the second transformer is connected to the drains of the first MOS transistors M1 and M3, the other end is connected to the drains of the first MOS transistors M2 and M4, and the center tap is connected to the power supply Vdd; One end of the secondary coil of the second transformer is connected to the source electrodes of the second MOS transistors M5 and M6, and the other end is connected to the source electrodes of the second MOS transistors M7 and M8, and the center tap is grounded; The gates of the second MOS transistors M5 and M8 are connected to the LO2+ signal terminal, and the gates of the second MOS transistors M6 and M7 are connected to the LO2- signal terminal; One end of the primary coil of the fifth transformer is connected in series with switch S1 and capacitor C1 to the LO2- signal terminal, and the other end is connected in series with switch S2 and capacitor C2 to the LO2+ signal terminal. One end of the secondary coil is connected to the LO signal terminal, and the other end is grounded.

2. The 5G dual-band up-mixer with switching of amplification and mixing functions as claimed in claim 1, characterized in that: A resistor R1 is connected between the LO1-signal terminal and the bias voltage Vb1, and a resistor R2 is connected between the LO1+signal terminal and the bias voltage Vb1.

3. The 5G dual-band up-mixer with switching of amplification and mixing functions as claimed in claim 1, characterized in that: A resistor R3 is connected between the LO2-signal terminal and the bias voltage Vb2, and a resistor R4 is connected between the LO2+signal terminal and the bias voltage Vb3.

4. A wireless communication terminal, characterized in that: The wireless communication terminal is equipped with a 5G dual-band up-mixer with amplification and mixing function switching as described in any one of claims 1 to 3.

5. A 5G millimeter wave communication terminal, characterized in that: The 5G millimeter wave communication terminal is equipped with a 5G dual-band mixer with amplification and mixing function switching as described in any one of claims 1 to 3.

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