A radio frequency transmitting mixer and wireless communication terminal equipment
By using dual-balanced differential RF circuits and power synthesizers in RF transmit mixers, a single-ended output without the need for external barrons is achieved, which solves the problem of low output power of traditional CMOS inverter mixers, and reduces the overall machine size and cost and improve signal linearity and gain.
Patent Information
- Application Number
- CN202410744312.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-11
- Publication Date
- 2024-12-31
- Estimated Expiration
- 2044-06-11
AI Technical Summary
The output power of traditional CMOS inverter mixers is low and require external multi-stage power amplifiers, resulting in large size and high cost of the whole machine.
Design a radio frequency transmitting mixer, including a dual-balanced differential RF circuit, an intermediate frequency differential circuit, an inverter and a power synthesizer, mix and modulate the intermediate frequency differential signal through a dual-balanced differential RF circuit, and use an inverter and power The synthesizer implements single-ended output, reducing dependence on external barrons.
The single-ended output of differential signals is realized, reducing the overall machine size and cost, while improving the linearity and gain of the output signal.
Smart Images
Figure CN118713603B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of wireless communications, and in particular to a radio frequency transmitting mixer. Background Art
[0002] The CMOS process is developed on the basis of PMOS and NMOS processes. The C in CMOS stands for "complementary", that is, NMOS devices and PMOS devices are made on the same silicon substrate to make CMOS integrated circuits. CMOS integrated circuits have many advantages such as low power consumption, high speed, strong anti-interference ability, and high integration. The CMOS process has become the mainstream process technology for current large-scale integrated circuits, and most integrated circuits are manufactured using the CMOS process.
[0003] Traditionally, upconversion mixers also use silicon-based CMOS technology, with low output power. Usually, an additional PA (Power Amplifier) is required in the system link to amplify the power and drive the antenna to transmit the signal. Traditional CMOS upconversion mixers have differential outputs. In the system transmission link, an external balun is required to convert the differential signal into a single-ended signal to drive the PA. Since the silicon-based chip has low output power and poor linearity, a multi-stage PA needs to be connected externally according to the transmission power requirements, which results in large size and high cost of the whole machine.
[0004] In view of this, how to design a single-ended output RF transmission mixer and a wireless communication terminal device with small overall size and low cost has become a problem that needs to be solved by those skilled in the art. Summary of the invention
[0005] The purpose of the embodiments of the present invention is to provide a radio frequency transmission mixer and a wireless communication terminal device, which can realize the single-ended output of a differential signal, thereby reducing the size of the whole device and lowering the product cost.
[0006] To solve the above technical problems, the embodiments of the present invention provide the following technical solutions:
[0007] In one aspect, the present invention provides a radio frequency transmission mixer, comprising a double-balanced differential radio frequency circuit, an intermediate frequency differential circuit, an inverter and a power synthesizer, wherein:
[0008] The first input terminal and the second input terminal of the double-balanced differential RF circuit are both used to receive a first local oscillator signal, the third input terminal of the double-balanced differential RF circuit is used to receive a second local oscillator signal, the first local oscillator signal and the second local oscillator signal constitute a local oscillator differential signal, the fourth input terminal of the double-balanced differential RF circuit is connected to the first output terminal of the intermediate frequency differential circuit, the fifth input terminal of the double-balanced differential RF circuit is connected to the second output terminal of the intermediate frequency differential circuit, the first output terminal or the second output terminal of the double-balanced differential RF circuit is connected to the input terminal of the inverter, the output terminal of the inverter and the second output terminal and one end of the first output terminal of the double-balanced differential RF circuit not connected to the inverter are connected to the input terminal of the power synthesizer, and the output terminal of the power synthesizer serves as the output terminal of the RF transmitting mixer; the first input terminal of the intermediate frequency differential circuit is used to receive a first intermediate frequency signal, the second input terminal of the intermediate frequency differential circuit is used to receive a second intermediate frequency signal, the first intermediate frequency signal and the second intermediate frequency signal constitute an intermediate frequency differential signal;
[0009] The intermediate frequency differential circuit is used to amplify the intermediate frequency differential signal and then output it;
[0010] The double-balanced differential radio frequency circuit is used to mix the amplified intermediate frequency differential signal and modulate the intermediate frequency differential signal onto the local oscillator signal to obtain a radio frequency differential output signal.
[0011] In an exemplary embodiment, the present invention further comprises a radio frequency operational amplifier, wherein a first input terminal of the radio frequency operational amplifier is connected to a first output terminal of the double-balanced differential radio frequency circuit, a second input terminal of the radio frequency operational amplifier is connected to a second output terminal of the double-balanced differential radio frequency circuit, a first output terminal or a second output terminal of the radio frequency operational amplifier is connected to an input terminal of the inverter, and an output terminal of the inverter and one end of the second output terminal and the first output terminal of the radio frequency operational amplifier that is not connected to the inverter are connected to an input terminal of the power combiner;
[0012] The radio frequency operational amplifier is used to adjust the linearity and gain of the output signal of the radio frequency transmitting mixer.
[0013] In an exemplary embodiment, the radio frequency operational amplifier includes an operational amplifier, a first variable resistor and a second variable resistor, wherein:
[0014] The non-inverting input terminal of the operational amplifier serves as the first input terminal of the RF operational amplifier, the inverting input terminal of the operational amplifier serves as the second input terminal of the RF operational amplifier, the first end of the first variable resistor is connected to the non-inverting input terminal of the operational amplifier, the non-inverting output terminal of the operational amplifier serves as the first output terminal of the RF operational amplifier, the inverting output terminal of the operational amplifier serves as the second output terminal of the RF operational amplifier, the second end of the first variable resistor is connected to the non-inverting output terminal of the operational amplifier, the first end of the second variable resistor is connected to the inverting input terminal of the operational amplifier, and the second end of the second variable resistor is connected to the inverting output terminal of the operational amplifier.
[0015] In an exemplary embodiment, the double-balanced differential RF circuit is an active double-balanced Gilbert circuit.
[0016] In an exemplary embodiment, the active double balanced Gilbert circuit includes a first NMOS transistor, a second NMOS transistor, a third NMOS transistor, a fourth PMOS transistor, a first constant current source and a second constant current source, wherein:
[0017] The gate of the first NMOS tube serves as the first input terminal of the double balanced differential RF circuit, and the gate of the fourth NMOS tube serves as the second input terminal of the double balanced differential RF circuit; the drain of the first NMOS tube, the drain of the third NMOS tube and the output terminal of the first constant current source are connected to each other, and the common terminal formed by the connection serves as the first output terminal of the double balanced differential RF circuit; the drain of the second NMOS tube, the drain of the fourth NMOS tube and the output terminal of the second constant current source are connected to each other, and the common terminal formed by the connection serves as the second output terminal of the double balanced differential RF circuit; the source of the first NMOS tube is connected to the source of the second NMOS tube, and the common terminal formed by the connection serves as the fourth input terminal of the double balanced differential RF circuit; the source of the third NMOS tube is connected to the source of the fourth NMOS tube, and the common terminal formed by the connection serves as the fifth input terminal of the double balanced RF circuit; the gate of the second NMOS tube is connected to the gate of the third NMOS tube, and the common terminal formed by the connection serves as the third input terminal of the double balanced RF circuit.
[0018] In an exemplary embodiment, the intermediate frequency differential circuit includes a first intermediate frequency differential sub-circuit and a second intermediate frequency differential sub-circuit, the input end of the first intermediate frequency differential sub-circuit serves as the first input end of the intermediate frequency differential circuit, the output end of the first intermediate frequency differential sub-circuit serves as the output end of the intermediate frequency differential circuit, the input end of the second intermediate frequency differential sub-circuit serves as the second input end of the intermediate frequency differential sub-circuit, and the output end of the second intermediate frequency differential sub-circuit serves as the output end of the intermediate frequency differential circuit; wherein the first intermediate frequency differential sub-circuit and the second intermediate frequency differential sub-circuit are symmetrical structures.
[0019] In an exemplary embodiment, the first intermediate frequency differential subcircuit includes a fifth NMOS transistor, the gate of the fifth NMOS transistor serves as the first input terminal of the intermediate frequency differential circuit, the drain of the fifth NMOS transistor serves as the first output terminal of the intermediate frequency differential circuit, and the source of the fifth NMOS transistor is grounded;
[0020] The second intermediate frequency differential subcircuit includes a sixth NMOS tube, the gate of the sixth NMOS tube serves as the second input end of the intermediate frequency differential circuit, the drain of the sixth NMOS tube serves as the second output end of the intermediate frequency differential circuit, and the source of the sixth NMOS tube is grounded.
[0021] In an exemplary embodiment, the first intermediate frequency sub-differential circuit further includes a second operational amplifier and a third variable resistor, the non-inverting input terminal of the second operational amplifier serves as the first input terminal of the intermediate frequency differential circuit, the inverting input terminal of the second operational amplifier is connected to the source of the fifth NMOS tube and the first terminal of the third variable resistor, the output terminal of the second operational amplifier is connected to the gate of the fifth NMOS tube, and the second terminal of the third variable resistor is grounded;
[0022] The second intermediate frequency differential subcircuit also includes a third operational amplifier and a fourth variable resistor, the non-phase input terminal of the third operational amplifier serves as the second input terminal of the intermediate frequency differential circuit, the inverting input terminal of the third operational amplifier is connected to the source of the sixth NMOS tube and the first end of the fourth variable resistor, the output terminal of the third operational amplifier is connected to the gate of the sixth NMOS tube, and the second end of the fourth variable resistor is grounded.
[0023] Another aspect of the present invention provides a wireless communication terminal device, comprising a radio frequency transmitting mixer as described in any one of the above.
[0024] It can be seen from the above technical solutions that the embodiments of the present invention have the following advantages:
[0025] An embodiment of the present invention provides a radio frequency transmitting mixer, comprising a double-balanced differential radio frequency circuit, an intermediate frequency differential circuit, an inverter and a power synthesizer, wherein: a first input terminal and a second input terminal of the double-balanced differential radio frequency circuit are both used to receive a first local oscillator signal, a third input terminal of the double-balanced differential radio frequency circuit is used to receive a second local oscillator signal, the first local oscillator signal and the second local oscillator signal constitute a local oscillator differential signal, a fourth input terminal of the double-balanced differential radio frequency circuit is connected to a first output terminal of the intermediate frequency differential circuit, a fifth input terminal of the double-balanced differential radio frequency circuit is connected to a second output terminal of the intermediate frequency differential circuit, and a first output terminal or a second output terminal of the double-balanced differential radio frequency circuit is connected to an input terminal of the inverter. The output end of the inverter and the second output end of the double-balanced differential RF circuit and one end of the first output end not connected to the inverter are connected to the input end of the power synthesizer, and the output end of the power synthesizer serves as the output end of the RF transmitting mixer; the first input end of the intermediate frequency differential circuit is used to receive the first intermediate frequency signal, and the second input end of the intermediate frequency differential circuit is used to receive the second intermediate frequency signal, and the first intermediate frequency signal and the second intermediate frequency signal constitute an intermediate frequency differential signal; the intermediate frequency differential circuit is used to amplify the intermediate frequency differential signal and then output it; the double-balanced differential RF circuit is used to mix the amplified intermediate frequency differential signal, and modulate the intermediate frequency differential signal to the local oscillator signal to obtain an RF differential output signal.
[0026] It can be seen that the input signal of the double-balanced differential RF circuit in the embodiment of the present invention is the local oscillator differential signal and the amplified intermediate frequency differential signal provided by the intermediate frequency differential circuit. The intermediate frequency differential signal is modulated onto the local oscillator differential signal for output. The first output end and the second output end of the double-balanced differential RF circuit output a differential signal. In the present application, an inverter is added to one of the first output end and the second output end of the double-balanced differential RF circuit to invert the phase of the output signal at one end. The phase of the inverted output signal is the same as the phase of the output signal at the other end. Therefore, a power synthesizer can be used to power synthesize the output signal at the other end with the inverted output signal to obtain the final output RF signal. That is, the present application does not require an additional external balun to achieve single-ended output of the differential signal, which is beneficial to reducing the size of the entire machine and reducing product costs.
[0027] In addition, the present invention also provides a corresponding wireless communication terminal device for the radio frequency transmission mixer, which has corresponding advantages.
[0028] It is to be understood that the foregoing general description and the following detailed description are exemplary only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the prior art and the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0030] Figure 1 A schematic diagram of the structure of a radio frequency transmission mixer provided by an embodiment of the present invention;
[0031] Figure 2 A schematic diagram of the structure of another radio frequency transmission mixer provided by an embodiment of the present invention;
[0032] Figure 3 A schematic structural diagram of another radio frequency transmitting mixer provided in an embodiment of the present invention. DETAILED DESCRIPTION
[0033] The embodiments of the present invention provide a radio frequency transmission mixer and a wireless communication terminal device, which can realize the single-ended output of a differential signal, thereby reducing the size of the whole device and lowering the product cost.
[0034] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0035] Please refer to Figure 1 , Figure 1 The schematic diagram of the structure of a radio frequency transmitting mixer provided by an embodiment of the present invention. The radio frequency transmitting mixer comprises a double-balanced differential radio frequency circuit 1, an intermediate frequency differential circuit 2, an inverter 3 and a power synthesizer 4, wherein:
[0036] The first input terminal 1a and the second input terminal 1b of the double-balanced differential RF circuit 1 are both used to receive a first local oscillator signal. The third input terminal 1c of the double-balanced differential RF circuit 1 is used to receive a second local oscillator signal. The first local oscillator signal and the second local oscillator signal constitute a local oscillator differential signal. The fourth input terminal 1d of the double-balanced differential RF circuit 1 is connected to the first output terminal 2c of the intermediate frequency differential circuit 2. The fifth input terminal 1e of the double-balanced differential RF circuit 1 is connected to the second output terminal 2d of the intermediate frequency differential circuit 2. The first output terminal 1f or the first output terminal 1f of the double-balanced differential RF circuit 1 is connected to the first output terminal 2c of the intermediate frequency differential circuit 2. The second output terminal 1g is connected to the input terminal 3a of the inverter 3, the output terminal 3b of the inverter 3 and the second output terminal 1g of the double-balanced differential RF circuit 1 and the end of the first output terminal 1f not connected to the inverter 3 are connected to the input terminal 4a of the power synthesizer 4, and the output terminal 4b of the power synthesizer 4 is used as the output terminal of the RF transmission mixer; the first input terminal 2a of the intermediate frequency differential circuit 2 is used to receive the first intermediate frequency signal, and the second input terminal 2b of the intermediate frequency differential circuit 2 is used to receive the second intermediate frequency signal, and the first intermediate frequency signal and the second intermediate frequency signal constitute an intermediate frequency differential signal;
[0037] The intermediate frequency differential circuit 2 is used for amplifying the intermediate frequency differential signal and then outputting it;
[0038] The double-balanced differential radio frequency circuit 1 is used for mixing the amplified intermediate frequency differential signal and modulating the intermediate frequency differential signal onto the local oscillator signal to obtain a radio frequency differential output signal.
[0039] It should be noted that the input signal of the intermediate frequency differential circuit 2 in the embodiment of the present invention is an intermediate frequency differential signal composed of the first intermediate frequency signal IFp and the second intermediate frequency signal IPn. The intermediate frequency differential circuit 2 amplifies the intermediate frequency differential signal and outputs the amplified intermediate frequency differential signal to the double-balanced differential RF circuit 1. The input of the double-balanced differential RF circuit 1 includes a local oscillator differential signal (composed of the first local oscillator signal LOp and the second local oscillator signal LOn) and the amplified intermediate frequency differential signal. The double-balanced differential RF circuit 1 mixes the amplified intermediate frequency differential signal according to the local oscillator signal, modulates the amplified intermediate frequency differential signal onto the local oscillator signal, and obtains a corresponding RF differential output signal. The output of the double-balanced differential RF circuit 1 in the embodiment of the present invention is a double-ended output, and the two outputs The output signal of the first output terminal or the second output terminal of the double-balanced differential RF circuit 1 is a differential signal with opposite phases. Therefore, the output signal obtained by inverting the output signal of the first output terminal or the second output terminal of the double-balanced differential RF circuit 1 through the inverter 3 can be the same in phase with the output signal of the other output terminal of the double-balanced differential RF circuit 1. Therefore, the output signal obtained by inverting the inverter 3 and the output signal of the other output terminal of the double-balanced differential RF circuit 1 can be transmitted to the power synthesizer 4, so that the power synthesizer 4 can perform power synthesis processing on the two received signals to obtain the power-synthesized RF output signal as the final output signal of the RF transmitting mixer, thereby realizing the single-ended output of the RF transmitting mixer, and the power synthesis processing of the signal by the power synthesizer 4 can ensure that the output power is not lost.
[0040] Based on the above embodiments, the embodiments of the present invention further illustrate and optimize the technical solution. Figure 2 and Figure 3 :
[0041] In one embodiment, the RF transmitting mixer may further include an RF operational amplifier 5, wherein a first input terminal of the RF operational amplifier 5 is connected to a first output terminal 1f of the double-balanced differential RF circuit 1, a second input terminal of the RF operational amplifier 5 is connected to a second output terminal 1g of the double-balanced differential RF circuit 1, a first output terminal or a second output terminal of the RF operational amplifier 5 is connected to an input terminal 3a of an inverter 3, an output terminal 3b of the inverter 3 and one end of the second output terminal and the first output terminal of the RF operational amplifier 5 that is not connected to the inverter 3 are connected to an input terminal 4a of a power synthesizer 4;
[0042] The radio frequency operational amplifier 5 is used to adjust the linearity and gain of the output signal of the radio frequency transmitting mixer.
[0043] It should be noted that, in order to further improve the linearity of the output signal in the embodiment of the present invention, a radio frequency operational amplifier 5 can be arranged between the output end of the double-balanced differential radio frequency circuit 1 and the inverter 3, and the radio frequency operational amplifier 5 can be used to adjust the linearity and gain of the output signal of the radio frequency transmitting mixer, and the output power can also be improved. The output signal of the double-balanced differential radio frequency circuit 1 is amplified by the radio frequency operational amplifier 5, and the linearity of the output signal can be improved while increasing the gain and power.
[0044] Specifically, the RF operational amplifier 5 in the embodiment of the present invention may include an operational amplifier 51, a first variable resistor 52 and a second variable resistor 53, wherein:
[0045] The non-inverting input terminal of the operational amplifier 51 serves as the first input terminal of the RF operational amplifier 5, the inverting input terminal of the operational amplifier 51 serves as the second input terminal of the RF operational amplifier 5, the first end of the first variable resistor 52 is connected to the non-inverting input terminal of the operational amplifier 51, the non-inverting output terminal of the operational amplifier 51 serves as the first output terminal of the RF operational amplifier 5, the inverting output terminal of the operational amplifier 51 serves as the second output terminal of the RF operational amplifier 5, the second end of the first variable resistor 52 is connected to the non-inverting output terminal of the operational amplifier 51, the first end of the second variable resistor 53 is connected to the inverting input terminal of the operational amplifier 51, and the second end of the second variable resistor 53 is connected to the inverting output terminal of the operational amplifier 51.
[0046] It should be noted that the first variable resistor 52 and the second variable resistor 53 in the RF operational amplifier 5 in the embodiment of the present invention serve as feedback resistors, and the gain can be adjusted by adjusting the resistance values of the first variable resistor 52 and the second variable resistor 53, thereby increasing the flexibility of link gain and power adjustment and being able to better adjust the optimal linearity output.
[0047] In one implementation, in order to obtain a higher frequency conversion range in the embodiment of the present invention, the double-balanced differential RF circuit 1 may use an active double-balanced Gilbert circuit.
[0048] Specifically, the active double balanced Gilbert circuit includes a first NMOS transistor 11, a second NMOS transistor 12, a third NMOS transistor 13, a fourth PMOS transistor 14, a first constant current source 15 and a second constant current source 16, wherein:
[0049] The gate of the first NMOS transistor 11 serves as the first input terminal 1a of the double-balanced differential RF circuit 1, and the gate of the fourth NMOS transistor 14 serves as the second input terminal 1b of the double-balanced differential RF circuit; the drain of the first NMOS transistor 11, the drain of the third NMOS transistor 13 and the output terminal of the first constant current source 15 are connected to each other, and the common terminal formed by the connection serves as the first output terminal 1f of the double-balanced differential RF circuit 1; the drain of the second NMOS transistor 12, the drain of the fourth NMOS transistor 14 and the output terminal of the second constant current source 16 are connected to each other, and the common terminal formed by the connection serves as the first output terminal 1f of the double-balanced differential RF circuit 1. It is the second output terminal 1g of the double balanced differential RF circuit 1; the source of the first NMOS tube 11 is connected to the source of the second NMOS tube 12, and the common terminal formed by the connection serves as the fourth input terminal 1d of the double balanced differential RF circuit 1; the source of the third NMOS tube 13 is connected to the source of the fourth NMOS tube 14, and the common terminal formed by the connection serves as the fifth input terminal 1e of the double balanced RF circuit 1; the gate of the second NMOS tube 12 is connected to the gate of the third NMOS tube 13, and the common terminal formed by the connection serves as the third input terminal 1c of the double balanced RF circuit 1.
[0050] It should be noted that the active double balanced Gilbert circuit in the embodiment of the present invention is composed of a first NMOS transistor 11, a second NMOS transistor 12, a third NMOS transistor 13, a fourth NMOS transistor 14, a first constant current source 15, and a second constant current source 16, wherein the first NMOS transistor 11 and the second NMOS transistor 12 constitute a first differential pair, the third NMOS transistor 13 and the fourth NMOS transistor 14 constitute a second differential pair, the first NMOS transistor 11, the second NMOS transistor 12, the third NMOS transistor 13, and the fourth NMOS transistor 14 all work in the linear region, and the first local oscillation signal LOp is connected to the first NMOS transistor 11. The gate of the intermediate frequency differential circuit 2 is connected to the gate of the first NMOS tube 11 and the gate of the fourth NMOS tube 14, the second local oscillation signal LOn is connected to the gate of the second NMOS tube 12 and the gate of the third NMOS tube 13, the intermediate frequency differential signal output by the first output terminal 2c of the intermediate frequency differential circuit 2 is connected to the source of the first NMOS tube 11 and the second NMOS tube 12, the intermediate frequency differential signal output by the second output terminal 2d of the intermediate frequency differential circuit 2 is connected to the source of the third NMOS tube 13 and the fourth NMOS tube 14, and the intermediate frequency differential signal can be modulated onto the local oscillation signal through the first differential pair, the second differential pair, the first constant current source 15 and the second constant current source 16 to obtain a radio frequency differential output signal.
[0051] In one embodiment, the intermediate frequency differential circuit 2 in the embodiment of the present invention may include a first intermediate frequency differential sub-circuit 21 and a second intermediate frequency differential sub-circuit 22, the input end of the first intermediate frequency differential sub-circuit 21 serves as the first input end of the intermediate frequency differential circuit 2, the output end of the first intermediate frequency differential sub-circuit 21 serves as the output end of the intermediate frequency differential circuit 2, the input end of the second intermediate frequency differential sub-circuit 22 serves as the second input end of the intermediate frequency differential sub-circuit 2, and the output end of the second intermediate frequency differential sub-circuit 22 serves as the output end of the intermediate frequency differential circuit 2; wherein the first intermediate frequency differential sub-circuit 21 and the second intermediate frequency differential sub-circuit 22 are symmetrical structures.
[0052] For details, please refer to Figure 2 The first intermediate frequency differential subcircuit in the embodiment of the present invention includes a fifth NMOS transistor 211, the gate of the fifth NMOS transistor 211 serves as the first input terminal of the intermediate frequency differential circuit 2, the drain of the fifth NMOS transistor 211 serves as the first output terminal of the intermediate frequency differential circuit 2, and the source of the fifth NMOS transistor is grounded;
[0053] The second intermediate frequency differential subcircuit 22 includes a sixth NMOS transistor 221, a gate of the sixth NMOS transistor 221 as a second input terminal of the intermediate frequency differential circuit, a drain of the sixth NMOS transistor 221 as a second output terminal of the intermediate frequency differential circuit, and a source of the sixth NMOS transistor 221 grounded.
[0054] It should be noted that, in the embodiment of the present invention, the intermediate frequency differential circuit 2 composed of the fifth NMOS transistor 211 and the sixth NMOS transistor 221 can be used to amplify the input intermediate frequency differential signal.
[0055] Furthermore, in order to increase the adjustable range of gain, such as Figure 3 As shown, the first intermediate frequency sub-differential circuit 21 in the present invention also includes a second operational amplifier 212 and a third variable resistor 213, the non-inverting input terminal of the second operational amplifier 212 serves as the first input terminal of the intermediate frequency differential circuit 2, the inverting input terminal of the second operational amplifier 212 is connected to the source of the fifth NMOS tube 211 and the first terminal of the third variable resistor 213, the output terminal of the second operational amplifier 212 is connected to the gate of the fifth NMOS tube 211, and the second terminal of the third variable resistor 213 is grounded;
[0056] The second intermediate frequency differential subcircuit 22 also includes a third operational amplifier 222 and a fourth variable resistor 223. The non-inverting input terminal of the third operational amplifier 222 serves as the second input terminal of the intermediate frequency differential circuit 2. The inverting input terminal of the third operational amplifier 222 is connected to the source of the sixth NMOS tube 221 and the first end of the fourth variable resistor 223. The output terminal of the third operational amplifier 222 is connected to the gate of the sixth NMOS tube 221. The second end of the fourth variable resistor 223 is grounded.
[0057] It should be noted that since the resistance values of the third variable resistor 213 and the fourth variable resistor 223 are adjustable, the overall gain can be adjusted by adjusting the load resistance values of the third variable resistor 213 and the fourth variable resistor 223 in the embodiment of the present invention, so that the adjustable range of the value-added is larger, which is conducive to improving the flexibility of the product.
[0058] In practical applications, the RF transmitting mixer in this application can be made into a chip product to better meet actual needs.
[0059] It can be seen that the input signal of the double-balanced differential RF circuit in the embodiment of the present invention is the local oscillator differential signal and the amplified intermediate frequency differential signal provided by the intermediate frequency differential circuit. The intermediate frequency differential signal is modulated onto the local oscillator differential signal for output. The first output end and the second output end of the double-balanced differential RF circuit output a differential signal. In the present application, an inverter is added to one of the first output end and the second output end of the double-balanced differential RF circuit to invert the phase of the output signal at one end. The phase of the inverted output signal is the same as the phase of the output signal at the other end. Therefore, a power synthesizer can be used to power synthesize the output signal at the other end with the inverted output signal to obtain the final output RF signal. That is, the present application does not require an additional external balun to achieve single-ended output of the differential signal, which is beneficial to reducing the size of the entire machine and reducing product costs.
[0060] On the basis of the above embodiments, the present invention provides a wireless communication terminal device on the other hand, including a radio frequency transmitting mixer as described in any one of the above.
[0061] It should be noted that the wireless communication terminal device in the embodiment of the present invention has the same beneficial effects as the RF transmit mixer provided in the above embodiment, and for the specific introduction of the RF transmit mixer involved in the embodiment of the present invention, please refer to the above embodiment, and this application will not go into details here.
[0062] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.
[0063] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.
[0064] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A radio frequency transmitting mixer, characterized in that: It includes a double-balanced differential radio frequency circuit, an intermediate frequency differential circuit, an inverter and a power synthesizer, wherein: The first input terminal and the second input terminal of the double-balanced differential RF circuit are both used to receive a first local oscillator signal, the third input terminal of the double-balanced differential RF circuit is used to receive a second local oscillator signal, the first local oscillator signal and the second local oscillator signal constitute a local oscillator differential signal, the fourth input terminal of the double-balanced differential RF circuit is connected to the first output terminal of the intermediate frequency differential circuit, the fifth input terminal of the double-balanced differential RF circuit is connected to the second output terminal of the intermediate frequency differential circuit, the first output terminal or the second output terminal of the double-balanced differential RF circuit is connected to the input terminal of the inverter, the output terminal of the inverter and the second output terminal and one end of the first output terminal of the double-balanced differential RF circuit not connected to the inverter are connected to the input terminal of the power synthesizer, and the output terminal of the power synthesizer serves as the output terminal of the RF transmitting mixer; the first input terminal of the intermediate frequency differential circuit is used to receive a first intermediate frequency signal, the second input terminal of the intermediate frequency differential circuit is used to receive a second intermediate frequency signal, the first intermediate frequency signal and the second intermediate frequency signal constitute an intermediate frequency differential signal; The intermediate frequency differential circuit is used to amplify the intermediate frequency differential signal and then output it; The double-balanced differential RF circuit is used to mix the amplified intermediate frequency differential signal and modulate the intermediate frequency differential signal onto the local oscillator signal to obtain an RF differential output signal; wherein: The double-balanced differential radio frequency circuit is an active double-balanced Gilbert circuit; The active double-balanced Gilbert circuit comprises a first NMOS transistor, a second NMOS transistor, a third NMOS transistor, a fourth NMOS transistor, a first constant current source and a second constant current source, wherein: The gate of the first NMOS tube serves as the first input terminal of the double balanced differential RF circuit, and the gate of the fourth NMOS tube serves as the second input terminal of the double balanced differential RF circuit; the drain of the first NMOS tube, the drain of the third NMOS tube and the output terminal of the first constant current source are connected to each other, and the common terminal formed by the connection serves as the first output terminal of the double balanced differential RF circuit; the drain of the second NMOS tube, the drain of the fourth NMOS tube and the output terminal of the second constant current source are connected to each other, and the common terminal formed by the connection serves as the second output terminal of the double balanced differential RF circuit; the source of the first NMOS tube is connected to the source of the second NMOS tube, and the common terminal formed by the connection serves as the fourth input terminal of the double balanced differential RF circuit; the source of the third NMOS tube is connected to the source of the fourth NMOS tube, and the common terminal formed by the connection serves as the fifth input terminal of the double balanced differential RF circuit; the gate of the second NMOS tube is connected to the gate of the third NMOS tube, and the common terminal formed by the connection serves as the third input terminal of the double balanced differential RF circuit.
2. The radio frequency transmitting mixer according to claim 1, characterized in that: It also includes a radio frequency operational amplifier, wherein the first input end of the radio frequency operational amplifier is connected to the first output end of the double-balanced differential radio frequency circuit, the second input end of the radio frequency operational amplifier is connected to the second output end of the double-balanced differential radio frequency circuit, the first output end or the second output end of the radio frequency operational amplifier is connected to the input end of the inverter, and the output end of the inverter and one end of the second output end and the first output end of the radio frequency operational amplifier that is not connected to the inverter are connected to the input end of the power synthesizer; The radio frequency operational amplifier is used to adjust the linearity and gain of the output signal of the radio frequency transmitting mixer.
3. The radio frequency transmitting mixer according to claim 2, characterized in that: The radio frequency operational amplifier comprises an operational amplifier, a first variable resistor and a second variable resistor, wherein: The non-inverting input terminal of the operational amplifier serves as the first input terminal of the RF operational amplifier, the inverting input terminal of the operational amplifier serves as the second input terminal of the RF operational amplifier, the first end of the first variable resistor is connected to the non-inverting input terminal of the operational amplifier, the non-inverting output terminal of the operational amplifier serves as the first output terminal of the RF operational amplifier, the inverting output terminal of the operational amplifier serves as the second output terminal of the RF operational amplifier, the second end of the first variable resistor is connected to the non-inverting output terminal of the operational amplifier, the first end of the second variable resistor is connected to the inverting input terminal of the operational amplifier, and the second end of the second variable resistor is connected to the inverting output terminal of the operational amplifier.
4. The radio frequency transmitting mixer according to claim 1, characterized in that: The intermediate frequency differential circuit includes a first intermediate frequency differential sub-circuit and a second intermediate frequency differential sub-circuit, the input end of the first intermediate frequency differential sub-circuit serves as the first input end of the intermediate frequency differential circuit, the output end of the first intermediate frequency differential sub-circuit serves as the output end of the intermediate frequency differential circuit, the input end of the second intermediate frequency differential sub-circuit serves as the second input end of the intermediate frequency differential sub-circuit, and the output end of the second intermediate frequency differential sub-circuit serves as the output end of the intermediate frequency differential circuit; wherein the first intermediate frequency differential sub-circuit and the second intermediate frequency differential sub-circuit are symmetrical structures.
5. The radio frequency transmitting mixer according to claim 4, characterized in that: The first intermediate frequency differential subcircuit includes a fifth NMOS transistor, the gate of the fifth NMOS transistor serves as the first input terminal of the intermediate frequency differential circuit, the drain of the fifth NMOS transistor serves as the first output terminal of the intermediate frequency differential circuit, and the source of the fifth NMOS transistor is grounded; The second intermediate frequency differential subcircuit includes a sixth NMOS tube, the gate of the sixth NMOS tube serves as the second input end of the intermediate frequency differential circuit, the drain of the sixth NMOS tube serves as the second output end of the intermediate frequency differential circuit, and the source of the sixth NMOS tube is grounded.
6. The radio frequency transmitting mixer according to claim 5, characterized in that: The first intermediate frequency differential subcircuit further includes a second operational amplifier and a third variable resistor, the non-inverting input terminal of the second operational amplifier serves as the first input terminal of the intermediate frequency differential circuit, the inverting input terminal of the second operational amplifier is connected to the source of the fifth NMOS tube and the first terminal of the third variable resistor, the output terminal of the second operational amplifier is connected to the gate of the fifth NMOS tube, and the second terminal of the third variable resistor is grounded; The second intermediate frequency differential subcircuit also includes a third operational amplifier and a fourth variable resistor, the non-phase input terminal of the third operational amplifier serves as the second input terminal of the intermediate frequency differential circuit, the inverting input terminal of the third operational amplifier is connected to the source of the sixth NMOS tube and the first end of the fourth variable resistor, the output terminal of the third operational amplifier is connected to the gate of the sixth NMOS tube, and the second end of the fourth variable resistor is grounded.
7. A wireless communication terminal device, characterized in that: Comprising the radio frequency transmitting mixer as described in any one of claims 1 to 6.