5G MILLIMETER WAVE DUAL-BAND DUAL-MODE MIXER AND WIRELESS COMMUNICATION TERMINAL

Abstract

This invention, falling into the field of radio communication technology, discloses 5G millimeter wave dual-band dual-mode mixer and wireless communication terminal. In the said 5G millimeter wave dual-band dual-mode mixer, the first MOSFET is connected to the source of the second MOSFET and the third MOSFET through its drain, with the first MOSFET connected to the drain of the fourth MOSFET through its drain. The second MOSFET is connected to one end of the first capacitor through its gate, with the other end of the first capacitor connected to the drain of the third MOSFET. The third MOSFET is connected to one end of the second capacitor through its gate and the other end of the second capacitor is connected to the drain of the second MOSFET.

Claims

1. A 5G millimeter wave dual-band dual-mode mixer characterized by the following settings: The first MOSFET; The first MOSFET is connected to the source of the second MOSFET and the third MOSFET and connected to the drain of the fourth MOSFET through its drain; The second MOSFET is connected to one end of the first capacitor through the gate, with the other end of the first capacitor connected to the drain of the third MOSFET; The third MOSFET is connected to one end of the second capacitor through the gate, with the other end of the second capacitor connected to the drain of the second MOSFET; The said second MOSFET and the third MOSFET are connected to the positive and negative ends of the local oscillator signal through their gates, and connected to the two ports of the primary coil of the transformer through their drains; The said transformer is connected to the Vdd after being cascaded with the first inductor through the center tap of the primary coil. The center tap of the secondary coil is connected to the ground, with the two ports of the secondary coil connected to the sources of the fifth MOSFET and the sixth MOSFET; The said sixth MOX tube is connected to bias voltage Vb2 through the gate, with the sixth MOSFET connected to the drain of the eighth MOSFET through its drain; The said fifth MOSFET is connected to bias voltage Vb2 through the gate and to the drain of the seventh MOSFET, the gate of the seventh MOSFET and the gate of the eighth MOSFET through its drain; The said seventh MOSFET and the eighth MOSFET are connected to the Vdd through the source; The said sixth MOSFET is connected to one end of the fourth capacitor through the drain, with the other end of the fourth capacitor connected to the first input end of the single-pole double-throw switch after being cascaded with the second inductor; The said transformer is connected to one end of the third capacitor through the center tap of the primary coil, with the other end of the third capacitor connected to the second input end of the single-pole double-throw switch. The output end of the single-pole double-throw switch is connected to the IF output port.

2. As described in claim 1, the said 5G millimeter wave dual-band dual-mode mixer is characterized by the fact that the said first MOSFET is connected to the ground through the source, and connected to the RF input signal through the gate, and the fourth MOSFET is connected to the Vdd through the source and connected to the bias voltage Vb1 through the gate.

3-8. (canceled)

9. (canceled)

10. (canceled)

11. A 5G millimeter wave communication receiver chip characterized by the following facts: the said 5G millimeter wave communication receiver chip includes the 5G millimeter wave dual-band dual-mode mixer described in any of claims 1-2, and it can operate under two millimeter wave frequency bands near 27 GHz and 39 GHz simultaneously.

12. A radio communication terminal characterized by the following fact: the said radio communication terminal is equipped with the 5G millimeter wave dual-band dual-mode mixer described in any of claims 1-2.

Description

INSTRUCTIONS ON DRAWINGS

[0027] FIG. 1 is the schematic drawing that shows the structure of the 5G millimeter wave dual-band dual-mode mixer provided by the embodiment of this invention;

[0028] FIG. 2 is the schematic drawing of the circuit of the dual-band down conversion solution with the function of suppressing image frequency provided by the embodiment of this invention.

[0029] FIG. 3 shows the principles of differential-mode and common-mode extraction performed by the transformer provided by the embodiment of this invention;

[0030] In FIG. 3: Fig. a shows the common mode, while Fig. b shows the different mode;

[0031] In the figure: 1. The first MOSFET; 2. The second MOSFET; 3. The third MOSFET; 4. The fourth MOSFET; 5. The fifth MOSFET; 6. The sixth MOSFET; 7. The seventh MOSFET; 8. The eighth MOSFET; 9. The first capacitor; 10. The second capacitor; 11. The third capacitor; 12. The fourth capacitor; 13. The first inductor; 14. The second inductor; 15. Single pole, double throw switch; 16. Transformer.

EMBODIMENT

[0032] To clarify the purpose of this invention, technical solution, and advantages, a detailed description of this invention is provided together with the following embodiment. It should be understood that the embodiment described herein can only be used to explain this invention, not limiting the invention.

[0033] I. Explanation of embodiment. To help technical personnel in this field fully understand how to realize this invention, a detailed description of the embodiment is offered in this part to explain the technical solution proposed in the claims.

[0034] As shown in FIG. 1, in the 5G millimeter wave dual-band dual-mode frequency converter provided in the embodiment of this invention, the source of the first MOSFET 1 is connected to ground, with its gate connected to the RF input signal and its drain connected to the source of the second MOSFET 2 and the third MOSFET 3. The source of the fourth MOSFET 4 is connected to Vdd, with its gate connected to the bias voltage Vb1 and its drain connected to the drain of the first MOSFET 1. The gates of the second MOSFET 2 and the third MOSFET 3 are connected to the positive and negative ends of the signal of the local oscillator, respectively, with the drains connected to the two ports of the primary coil of transformer 16. Transfer 16 is Transformer 1, and the center tap of its primary coil is connected to Vdd after being cascaded with the first inductor 13. The center tap of the secondary coil is grounded, while the ports on both sides of the secondary coil are connected to the sources of the fifth MOSFET 5 and the sixth MOSFET 6, respectively. One end of the first capacitor 9 is connected to the gate of the second MOSFET 2, with the other end connected to the drain of the third MOSFET 3. One end of the second capacitor 10 is connected to the gate of the third MOSFET 3, with the other end connected to the drain of the second MOSFET 2. The gate of the sixth MOSFET 6 is connected to the bias voltage Vb2, with its drain connected to the drain of the eighth MOSFET 8. The gate of the fifth MOSFET 5 is connected to the bias voltage Vb2, with its drain connected to the drain of the seventh MOSFET 7, the gate of the seventh MOSFET 7, and the gate of the eighth MOSFET 8. The sources of the seventh MOSFET 7 and the eighth MOSFET 8 are connected to the Vdd. One end of the fourth capacitor 12 is connected to the drain of the sixth MOSFET 6, with the other end connected to the first input end of the single pole double throw switch 15 after being cascaded with the second inductor 14. One end of the third capacitor 11 is connected to the center tap of the primary coil of transformer 16, with the other end connected to the second input end of the single-pole double-throw switch. The output end of the single-pole double-throw switch 15 is connected to the IF output port.

[0035] The operating principle of this invention: the first MOSFET 1, the second MOSFET 2, the third MOSFET 3, the fourth MOSFET 4, the first capacitor 9, and the second capacitor 10 together constitute the core of the mixer, a current injection type single balanced active mixer structure. The first MOSFET 1 provides gain for the mixer as the transconductance stage, and the fourth MOSFET 4 can increase the drain current of the first MOSFET 1 as the current injection structure, which can further increase the gain of the mixer. The second MOSFET 2 and the third MOSFET 3 is the switching tube of the mixer. The phase difference of the local oscillator signal to which the gate is connected is 180?. Since the local oscillator signal is relatively strong, the signal transmission expression under non-linear impact shall be considered:

[00001]$V_{ds}=a_1{V}_{gs}+a_2{V}_{gs}^2+a_3{V}_{gs}^3.Math.;$

[0036] Where, V.sub.ds refers to the drain-source voltage difference of the second MOSFET 2 or the third MOSFET 3; V.sub.gs is the gate-source voltage difference of the second MOSFET 2 or the third MOSFET 3. Under the effect of the local oscillator signal, a.sub.i refers to the relevant non-linear coefficient. For the second MOSFET 2, V.sub.gs=A cos(?.sub.LOt). The third MOSFET 3, V.sub.gs=?A cos(?.sub.LOt), where A refers to the voltage amplitude of the local oscillator signal, while ?.sub.LO represents the angular frequency of the local oscillator signal. The primary term is mixed with the fundamental wave of the local oscillator, with the second MOSFET 2 and the third MOSFET 3 breaking successively to perform frequency mixing with the RF signal entering from the source, outputting the signals of b.sub.1 cos(?.sub.RF??.sub.LO) and ?b.sub.1 cos(?.sub.RF??.sub.LO) respectively. Among the two signals, b.sub.1 is the voltage amplitude of the two signals and ?.sub.RF refers to the angular frequency of the RF signal. The two signals are equiamplitude phase-inverted signals and are output as differential-mode signals. The secondary term is mixed with the secondary harmonic wave of the local oscillator. V.sub.gs expression is substituted. Since the squared results of A and ?A are the same, there is no phase difference. The signal of the drain frequency mixing of the second MOSFET 2 or the third MOSFET 3 is output as the common signal b.sub.2 cos(2?.sub.LO??.sub.RF), with b.sub.2 being the voltage amplitude of the signal. To ensure the gain of secondary harmonic mixing, the gate DC voltage of the second MOSFET 2 and the third MOSFET 3 should be biased at a relatively large amplitude of the secondary harmonic near the threshold voltage. The first capacitor 9 and the second capacitor 10 are neutralizing capacitors used to ensure the operation stability of the second MOSFET 2 and the third MOSFET 3 of the mixer.

[0037] On one hand, transformer 16 (Transformer 1) is used to match with 4-6 GHz IF signal as the core load of the mixer. On the other hand, it is used to extract differential-mode signals and common-mode signals, with the extraction principle shown in FIG. 3. In FIG. 3, the primary coil is black and connected to the core of the mixer. The secondary coil is grey and connected to the source of the fifth MOSFET 5 and the sixth MOSFET 6. When the common-mode signal enters the primary coil (as shown in Fig. a of FIG. 3), the two signals go through half of the circumference of the primary coil. With the same amplitude and phase, the two signals are strengthened through superposition directly at the center tap. After being extracted from the center tap, given the symmetry and balance of transformer 16, the common-mode signal will not be coupled to the secondary coil and therefore will not be exported from the secondary coil. When the differential-mode signal enters the primary coil (as shown in Fig. b of FIG. 3) and the two signals go through the other half circumference of the primary coil and reach the center tap, they cancel each other as equiamplitude phase-inverted signals. The AC field can then be observed at the center tap of the primary coil, which means the signals would not flow out of the center tap. The differential-mode signal will travel a large circle from one port of the primary coil to the other, which will couple the electromagnetic energy to the secondary coil. Take the local oscillator 22 GHz as an example. The RF signal of 27 GHz can be mixed to produce a differential-mode signal of 27 GHz-22 GHz=5 GHz, which will then be coupled from the secondary coil of transformer 16. The RF signal of 39 GHz can be mixed to produce a common-mode signal of 2?22 GHz-39 GHz=5 GHz, which can be extracted through the center tap of the primary coil. In this way, the extraction of the differential-mode and common-mode signals generated after the frequency mixing process under two frequency bands is realized. The first inductor 13 is the load of the common-mode IF signal, and the third capacitor 11 is the capacitor that blocks the DC. The two form an LC matching network to guide the 4-6 GHz IF signal to single pole double throw switch 15. The first MOSFET 1 to the eighth MOSFET 8, the fourth capacitor 12, and the second inductor 14 form an active Balun. The differential-mode IF signal enters the source of the fifth MOSFET 5 and the sixth MOSFET 6 respectively from the two output ports of the secondary coil, with the fifth MOSFET 5 and the sixth MOSFET 6 forming a common gate structure, amplifying and outputting the signal from the drain. The signal from the drain of the fifth MOSFET 5 enters the gate of the eighth MOSFET 8 and is inverted once more to output from the drain of the eighth MOSFET 8, so the output signals from the drains of the sixth MOSFET 6 and the eighth MOSFET 8 are in the same phase and superimposed into the fourth capacitor 12. The fourth capacitor 12 is a DC-blocking capacitor, and the second inductor 14 forms a matching network with the fourth capacitor 12 to introduce the 4-6 GHz IF signal into the single-pole double-throw switch and, at the same time, to regulate the input impedance balance of the active Balun. The size of the fifth MOSFET 5 is slightly larger than the sixth MOSFET 6, and the size of the seventh MOSFET 7 is slightly larger than the eighth MOSFET 8, so the input impedance of the source of the fifth MOSFET 5 and the sixth MOSFET 6 is made similar. The single-pole double-throw switch 15 is used to select to output the extracted differential-mode or common-mode signal to the IF. When the local oscillator signal is 22 GHz, the image frequency of the 27 GHz RF signal is 17 GHz, while the image frequency of the 39 GHz RF signal being 49 GHz, both out of the RF band. In this way, the forestage matching network can be filtered. With such a method that performs fundamental wave mixing and secondary harmonic frequency mixing switching through differential-mode and common-mode extraction, it is possible to convert the information of two different frequency band RF into the same IF by switching the mode while maintaining the frequency of the local oscillator unchanged, significantly reducing the bandwidth design pressure of the IF and local oscillator.

[0038] When the IF bandwidth is f.sub.if1?f.sub.if2 and the range of the local oscillator is f.sub.lo1?f.sub.lo2, the RF end of the mixer can cover such two frequency bands as f.sub.if1+f.sub.lo1?f.sub.if2+f.sub.lo2 and 2f.sub.lo1?f.sub.if2?2f.sub.lo2?f.sub.if1. If the IF signal is 4-6 GHz while the local oscillator signal is 20-24 GHz, the two millimeter-wave bands 24.25-27.5 GHz and 37.5-42.5 GHz of the 5G communication used in China can be covered.

[0039] II. Application embodiment. To prove the inventiveness and technical value of the technical solution proposed by this invention, this part provides application embodiment of specific products or relevant technologies concerning the technical solution described in the claims. This invention can be applied to 5G millimeter wave communication receiver chips, enabling the chips to operate under the two millimeter wave frequency bands near 27 GHz and 39 GHz simultaneously.

[0040] III. Evidence of the effects achieved in the embodiment. The embodiment of this invention has achieved certain positive effects during the R&D or application. Compared with existing technologies, it has great advantages. The data and graphs of the text process are described as follows:

[0041] This invention can, by improving traditional single-balance active mixers, extract the differential-mode signal mixing by local oscillator fundamental wave and the common-mode signal mixing by local oscillator second harmonic through load transformer coupling and center tap extraction, which corresponds to the down-conversion of two frequency band signals of 5G communication. Then, different signal outputs are selected through active Balun, LC matching network, and single-pole, double-throw switch to realize a dual-mode down mixer applicable to a 5G millimeter wave dual-band receiver. This invention covers the two 5G millimeter wave bands under the RF frequency. However, the local oscillator bandwidth and IF bandwidth are relatively narrow, which means a heavy link burden would not be triggered. Compared with traditional solutions, this invention does not need the quadrature generator, t second mixer, and a 90? phase shifter, which means the local oscillator power demand is reduced with the layout simplified. Besides, the interference between the two bands can also be effectively suppressed with the image frequency being out-of-band. Therefore, the technical solution proposed is more suitable for the application of a 5G millimeter wave.

[0042] The description above is only the embodiment of this invention. However, the protection scope of this invention is not limited to this extent. All technical personnel who are familiar with this technical field are within the technical scope revealed by this invention, and any modification, alternative substitution, and improvement made in the spirit and under the principle of this invention shall be covered in its protection scope.