A millimeter wave transmitter capable of dynamically adjusting output power and a design method thereof

Abstract

The present invention provides a millimeter wave transmitter capable of dynamically adjusting output power and a design method, which relates to the field of radio frequency and millimeter wave communication technology, and includes an amplification module, a fixed matching network, a power detection module, a voltage bias module, a variable capacitor array matching network and a control module. The input signal enters the fixed matching network through the amplification module and is output through the antenna. The power detection module monitors the output power in real time and generates a feedback signal; the voltage bias module adjusts the bias voltage of the amplification module to achieve initial power adjustment; the variable capacitor array matching network is composed of a plurality of high-Q MIM capacitors, which are used to finely adjust the output impedance. The control module adjusts the bias voltage and the capacitor array combination based on a lookup table or an algorithm to achieve dynamic adjustment of the output power. The present invention combines coarse and fine adjustment mechanisms through closed-loop control to maintain output stability in complex environments. The system can quickly respond to temperature fluctuations, load changes and device aging to achieve efficient and stable power output.

Description

Technical Field

[0001] The present invention relates to the field of radio frequency and millimeter wave communication technology, and in particular to a millimeter wave transmitter capable of dynamically adjusting output power and a design method thereof. Background Art

[0002] Millimeter wave transmitters are key components in high-speed data communications, precision radar imaging, and high-frequency sensing, and are widely used in 5G communications, automotive radars, satellite communications, and high-frequency measurement equipment. The millimeter wave band can support higher communication rates and precise target detection due to its extremely wide bandwidth and excellent spatial resolution. However, with the complexity of the working environment and the diversification of application scenarios, the output power and performance stability of millimeter wave transmitters face many challenges.

[0003] Traditional millimeter wave transmitters usually use fixed bias voltage and fixed impedance matching network to achieve output power regulation and performance optimization. Under ideal conditions, this design can meet the performance requirements of the design target. However, in practical applications, the working environment is often accompanied by uncertain factors such as temperature changes, load impedance drift, and device aging. These factors will significantly affect the performance of the transmitter, which is manifested in the output power deviating from the target range, the power transmission efficiency is reduced, the reflection loss is increased, and the communication quality is deteriorated. For example:

[0004] (1) Temperature change: Temperature has a significant impact on the gain and output power of RF devices. When the ambient temperature rises, the amplifier gain usually decreases, resulting in insufficient output power; conversely, when the temperature drops, the amplifier gain increases, which may cause excessive output power, thereby shortening the device life or causing failure.

[0005] (2) Load impedance change: The load impedance of the transmitter is difficult to keep constant in actual working conditions. For example, the impedance of the antenna port may drift due to changes in installation conditions or environmental media. The fixed impedance matching network cannot adapt to impedance changes in real time, which will lead to increased reflection loss and reduced transmission efficiency, thus affecting the performance of the transmitter.

[0006] (3) Device aging and inherent component errors: The active devices (such as amplifiers) and passive devices (such as capacitors and inductors in matching networks) inside the transmitter will age over time, resulting in parameter drift. In addition, the inconsistency of device parameters during the manufacturing process will also have a negative impact on the overall performance.

[0007] In response to the above problems, some technical solutions have attempted to integrate a power detection module at the transmitter port to monitor the deviation of the output power. However, this type of detection function is usually only used to trigger the protection mechanism, lacks the corresponding dynamic adjustment capability, and cannot solve the complex changes in the actual working environment. In addition, relying solely on fixed bias or fixed matching design, it is difficult to balance power stability and transmission efficiency, which limits the adaptability of millimeter wave transmitters in changing environments. Summary of the invention

[0008] In order to overcome the defects of the prior art, the technical problem to be solved by the present invention is to propose a millimeter wave transmitter and a design method capable of dynamically adjusting the output power, and adopt the following technical solutions:

[0009] On the one hand, the present invention provides a millimeter wave transmitter capable of dynamically adjusting output power, comprising an amplification module and a fixed matching network, wherein an input signal is amplified by the amplification module and then input into the fixed matching network, wherein a transmitting antenna is arranged at the output end of the fixed matching network, and further comprising a power detection module, a voltage bias module, a variable capacitor array matching network and a control module, wherein the power detection module is arranged at the input end of the transmitting antenna, and is used to monitor the output power in real time and generate a feedback signal; the voltage bias module is connected to the amplification module, and is used to adjust the bias voltage of the amplification module, and perform preliminary adjustment on the output power of the transmitter; the variable capacitor array matching network is arranged between the output end and the ground end of the fixed matching network, and comprises a plurality of capacitors connected in parallel to each other, wherein each of the capacitors is respectively connected in series with a switch tube, and the plurality of switch tubes are turned on and off to form different capacitor combinations to change the output impedance, and perform fine adjustment on the output power; the control module is connected to the power detection module, the voltage bias module and the variable capacitor array matching network, and is used to receive the feedback signal, and adjust the bias voltage of the amplification module and the capacitor combination of the variable capacitor array matching network according to the feedback signal.

[0010] As a further improvement, the variable capacitor array matching network comprises six high-Q MIM capacitors connected in parallel, and the capacitor units are arranged in binary weighted manner.

[0011] As a further improvement, the dynamic adjustment range of the variable capacitor array matching network covers the output impedance Z OUT ∈[30,70]Ω, its equivalent capacitance C eq ∈[8.99,18.94]fF, step value ΔC=0.158fF.

[0012] As a further improvement, the power detection module includes a directional coupler and a detector, the input end of the directional coupler is connected to a fixed matching network, the output end is connected to an antenna, the coupling end is connected to the detector, and the isolation end is provided with a load; the output end of the detector is connected to the control module.

[0013] As a further improvement, the directional coupler is a microstrip line structure with a coupling ratio of -15dB, and a 50Ω matching resistor is connected to its output port to improve directivity and isolation.

[0014] Another aspect of the present invention provides a method for designing a millimeter wave transmitter capable of dynamically adjusting output power, comprising the following steps:

[0015] S10: Determine the target performance parameters of the transmitter, including:

[0016] Working frequency f;

[0017] Output power P OUT ∈[15,30]dBm;

[0018] Reflection coefficient S 11 ≤-15dB;

[0019] Output impedance range Z OUT ∈[Z MIN ,Z MAX ]Ω;

[0020] S20: Calculate the output impedance range Z based on the target performance parameters OUT and the step value ΔC of the variable capacitor array matching network;

[0021] S30: Use simulation tools to perform parameter traversal on frequency, temperature and load conditions, generate a lookup table, and record the optimal bias voltage V under each condition. bias And the equivalent capacitance C eq Configuration;

[0022] S40: Enter the lookup table into the control module for adjusting the bias voltage V during transmitter operation. bias And the equivalent capacitance C eq Configuration.

[0023] As a further improvement, in step S10, the operating frequency f=28 GHz, the output impedance range Z OUT ∈[30,70]Ω.

[0024] As a further improvement, step S20 further includes the following steps:

[0025] S21: Calculate the output impedance range Z OUT , output impedance range Z OUT The adjustment is achieved through a variable capacitor array matching network, and the output impedance and equivalent capacitance satisfy the following relationship:

[0026]

[0027] Among them, the equivalent capacitance C of the variable capacitor array matching network eq Satisfies the following relationship:

[0028]

[0029] In the formula, S i is the conduction state of the switch tube corresponding to the i-th capacitor, which is 1 when it is on and 0 when it is off; C i is the capacitance value of the i-th capacitor;

[0030] S22: Design a variable capacitor array matching network. The capacitor array is arranged in binary weighted order. The minimum capacitance value C unit It is equal to the value of the step value ΔC and satisfies the following relationship:

[0031]

[0032] Where N is the number of bits in the capacitor array.

[0033] As a further improvement, in the above step S30, the above different temperature conditions are T = -40 ° C, T = 0 ° C, T = 25 ° C and T = 125 ° C, and the above different load impedance conditions are Z load ∈[30,70]Ω.

[0034] As a further improvement, the calculation of the above target performance parameters is based on the operating frequency range f∈[24,30]GHz.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] First, the present invention uses a power detection module and a voltage bias module to construct a closed-loop feedback control system, dynamically adjusts the bias voltage of the amplifier module in combination with real-time feedback signals, and finely adjusts the output impedance with a variable capacitor array matching network, so that the millimeter wave transmitter can quickly respond to complex working conditions such as temperature changes, load impedance drift, and device aging. This design effectively improves the stability of the transmitter in a changing environment, ensures that the output power is stable within the target range, and is suitable for high-performance application scenarios such as 5G communications and millimeter wave radars.

[0037] Secondly, the present invention sets up a variable capacitor array matching network, which is composed of binary weighted high Q value MIM capacitor units and MOS switches, reducing hardware complexity and achieving high-precision impedance matching and flexible output power adjustment. The dynamic matching range covers Z OUT ∈[30,70]Ω, significantly reducing the reflection loss caused by load impedance drift or antenna mismatch, further optimizing the power transmission efficiency of the millimeter wave transmitter, while ensuring the reflection coefficient S 11≤-15, which improves communication quality and system performance.

[0038] Third, the present invention generates a lookup table and records the optimal bias voltage and equivalent capacitance under each environmental condition by traversing parameters under different nodes and load impedance ranges. The lookup table is entered into the control module, and the optimal parameter combination is quickly called for adjustment during system operation, which greatly reduces the adjustment time and improves the dynamic response speed and work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0040] Figure 1 It is a schematic diagram of the structure of the millimeter wave transmitter in the present invention;

[0041] Figure 2 A schematic diagram of the structure of a power amplifier circuit according to an embodiment of the present invention;

[0042] Figure 3 A schematic diagram of the structure of a driving amplifier circuit according to an embodiment of the present invention;

[0043] Figure 4 A schematic diagram of a variable capacitor array matching network structure according to an embodiment of the present invention;

[0044] Figure 5 A schematic diagram of the structure of a directional coupler according to an embodiment of the present invention;

[0045] Figure 6 FIG. 1 is a schematic diagram of the structure of a detector according to an embodiment of the present invention.

[0046] Reference numerals:

[0047] 1- amplification module; 2- power detection module; 3- voltage bias module; 4- variable capacitor array matching network; 5- control module; 6- transmitting antenna;

[0048] 21-directional coupler; 21a-input port; 21b-output port; 21c-coupling port; 21d-isolation port;

[0049] 22-detector; 22a-detector matching network; 22b-rectifier device; 22c-low-pass filter;

[0050] L1-fixed matching network; PA-power amplifier; DA-driver amplifier. DETAILED DESCRIPTION

[0051] In order to facilitate understanding by those skilled in the art, the structure of the present invention is further described in detail with reference to the embodiments in conjunction with the accompanying drawings:

[0052] In the description of the present invention, the orientation or positional relationship indicated by the terms "portion", "side", "end", etc. is based on the orientation or positional relationship shown in the drawings and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0053] like Figure 1 As shown, the present application provides a millimeter wave transmitter capable of dynamically adjusting output power, including an amplifier module 1 and a fixed matching network L1. The input signal is amplified by the amplifier module 1 and then input into the fixed matching network L1. The output end of the fixed matching network L1 is provided with a transmitting antenna 6. The amplifier module 1 specifically includes a driving amplifier DA and a power amplifier PA.

[0054] In a traditional transmitter, the transmission signal is generated by a signal source, and after being amplified step by step by a driver amplifier DA and a power amplifier PA, it is transferred to the output matching network for impedance matching, and finally the signal is emitted through the transmitting antenna 6. The amplification module 1 linearly amplifies the low-power signal of the signal source, increases the amplitude of the signal, and enables it to meet the target output power requirement. The function of the fixed matching network L1 is to adjust the output impedance of the transmitter to match the impedance of the transmitting antenna 6, thereby reducing reflection loss, improving power transmission efficiency, and ensuring that the transmission signal is transmitted to the antenna in the optimal state. However, traditional transmitters are usually designed with a fixed bias voltage and a fixed matching network L1. Although higher output power and lower reflection coefficient can be achieved under specific conditions, there are obvious limitations in actual use.

[0055] Therefore, the present invention further includes a power detection module 2, a voltage bias module 3, a variable capacitor array matching network 4 and a control module 5, such as Figure 1As shown, the power detection module 2 is arranged at the input end of the transmitting antenna 6, and is used to monitor the output power in real time and generate a feedback signal; the voltage bias module 3 is connected to the amplification module 1, and is used to adjust the bias voltage of the amplification module 1, and perform preliminary adjustment on the output power of the transmitter; the variable capacitor array matching network 4 is arranged between the output end and the ground end of the fixed matching network L1, and includes a plurality of capacitors connected in parallel, each capacitor is respectively connected in series with a switch tube, and the plurality of switch tubes are turned on and closed to form different capacitor combinations to change the output impedance, so as to perform fine adjustment on the output power; the control module 5 is connected to the power detection module 2, the voltage bias module 3 and the variable capacitor array matching network 4, and is used to receive the feedback signal, and adjust the bias voltage of the amplification module 1 and the capacitor combination of the variable capacitor array matching network 4 according to the feedback signal.

[0056] like Figure 1 and Figure 2 As shown, the power amplifier PA used in the present invention adopts a multi-unit parallel topology structure, and its function is to amplify the relatively small RF input signal in the transmission link to the desired output power level to drive the antenna to radiate millimeter wave signals. Specifically, the power amplifier PA includes an input transformer Tin, an output transformer Tout, a plurality of parallel amplification units, and an LC network for impedance matching. The input signal is introduced from the input end, and after being loaded by the primary coil of the input transformer Tin, it is distributed to the gates of the two parallel amplification units through electromagnetic coupling. Each amplification unit adopts a common source structure to provide higher gain and transconductance performance, and is designed for the characteristics of the millimeter wave frequency band to meet the high power output requirements. After the output signal is amplified by each amplification unit, it is connected to the output transformer Tout through the LC matching network for power synthesis.

[0057] Furthermore, in order to cope with the gain drift caused by temperature changes, device aging and manufacturing tolerances, the present invention sets an interface for adjusting the gate bias voltage Vg in the bias circuit. The control module 5 adjusts the bias voltage in real time according to the feedback signal of the power detection module 2 to compensate for the gain change of the amplification unit so that the output power is stabilized within the target range. Through the dynamic adjustment of the bias voltage, the power amplifier PA can quickly respond to the power deviation and realize the coarse adjustment of the power, providing a basic guarantee for the subsequent fine matching through the variable capacitor array matching network 4.

[0058] like Figure 1 and Figure 3 As shown, the driver amplifier DA is located before the power amplifier PA, and is used to amplify the front-stage signal to a level sufficient to drive the power amplifier PA to reach a desired output power range, wherein the front-stage signal comes from an upstream oscillator, modulator or frequency converter, etc.

[0059] Specifically, the driving amplifier DA of the present invention is composed of a two-stage common-source MOS tube amplification unit (M21 and M22), a broadband matching network (including inductors L21 to L26 and capacitors C21 to C26), a bias circuit and a power supply circuit, and is used to amplify the input RF signal to a power level sufficient to drive the power amplifier PA.

[0060] The input RF signal enters from the input terminal RF in, and firstly passes through the matching network composed of inductor L21, capacitor C21 and capacitor C22 to convert the external 50Ω input impedance into the input impedance value of the gate of the MOS tube M21. The drain of the MOS tube M21 is connected to the power supply voltage Vd through the inductor L22 and capacitor C23 to optimize the frequency response of the signal. The signal after the first stage of amplification is transmitted to the gate of the MOS tube M22 through the coupling capacitor C24. It should be pointed out that the capacitor C25 is also connected to the gate of M22 as a filtering and matching element, and forms a matching network with the inductor L24 to adjust the impedance characteristics of the input signal to ensure that the gain of M22 remains in the optimal state. The drain of M22 is connected to the output terminal RFout through the inductor L25, the inductor L26 and the capacitor C26.

[0061] The two-stage common source amplifier design of the driver amplifier DA enables it to have high linearity and gain. By adjusting the bias voltage Vg, the control module 5 can optimize the working state of the MOS tube M21 and the MOS tube M22 in real time. For example, when a higher output power is required, the control module 5 increases the bias voltage to increase the transconductance gain; when the power is too high or the temperature rises, the bias voltage is reduced to protect the device and reduce power consumption.

[0062] like Figure 4 As shown, the variable capacitor array matching network 4 includes six high-Q MIM capacitors connected in parallel, and the capacitor units are arranged in binary weighted manner.

[0063] In a specific embodiment, the number of bits of the capacitor matrix matching network is six, each MIM capacitor is connected to the circuit through a MOS switch, and the capacitance values ​​are arranged in binary weighted order, namely C1, 2C1, 4C1, 8C1, 16C1, and 32C1. The equivalent capacitance value of the variable capacitor array matching network 4 can be dynamically adjusted by controlling the on or off of the MOS switch. The six-bit binary weighted capacitor array can provide 2 6 -1 = 63 different capacitor combination states, with equivalent capacitance range of Where S i ∈{0,1},S i is the conduction state of the MOS switch tube corresponding to the i-th capacitor, with conduction being counted as 1 and disconnection being counted as 0. This achieves precise matching of the output impedance, simplifies the circuit structure, and improves the response speed and regulation accuracy of the system.

[0064] More specifically, the dynamic adjustment range of the variable capacitor array matching network 4 covers the output impedance Z OUT ∈[30,70]Ω, its equivalent capacitance C eq ∈[8.99,18.94]fF, step value ΔC=0.158fF.

[0065] like Figure 1 As shown, the power detection module 2 includes a directional coupler 21 and a detector 22, combined with Figure 5 , the coupler is usually a four-port device, including an input port 21a, an output port 21b, a coupling port 21c and an isolation port 21d. The input port 21a of the directional coupler 21 is connected to the fixed matching network L1, the output port 21b is connected to the antenna, and the coupling port 21c is connected to the detector 22, that is, the main signal is input from the input port 21a, and output to the output port 21b through the transmission line structure. The coupling line is closely parallel to the main line for a distance, and a small part of the power is obtained through electromagnetic field coupling and output to the coupling port 21c. At the same time, a matching load is connected to the isolation port 21d to improve the directivity and isolation. Under millimeter waves, the coupler generally adopts a microstrip line or coplanar waveguide transmission line structure, and optimizes the line width, spacing, and length through electromagnetic simulation (such as HFSS, ADS, etc.) to obtain the required coupling ratio (such as -15dB). Select low-loss dielectric materials and high-quality metal layers to reduce insertion loss and phase imbalance. The isolation port 21d is often connected to a 50Ω matching resistor to ensure isolation and reduce the impact of back reflection on the main line.

[0066] Furthermore, the output end of the detector 22 is connected to the control module 5. The detector 22 module is responsible for converting the millimeter wave radio frequency signal from the directional coupler 21 into a DC level for the controller to read and determine the power state. Figure 6 In the illustrated embodiment, the detector 22 is composed of a detector matching network 22a, a rectifying device 22b and a low-pass filter 22c. In this embodiment, the rectifying device is a Schottky detector diode.

[0067] In combination with the above content, what can be achieved is that when the system is powered on, the control module 5 (such as MCU or FPGA) is first initialized, and the bias voltage of the power amplifier PA, the driving amplifier DA and the capacitance combination of the variable capacitance array matching network 4 are set to the nominal value, and the transmitter enters the initial working state. The power detection module 2 couples out a part of the RF signal through the directional coupler 21 and loads it onto the Schottky detection diode, and uses its nonlinear rectification characteristics to convert the forward half cycle of the RF signal into a DC level signal. The signal is smoothed and output by a low-pass filter, and has a monotonic relationship with the output power.

[0068] Furthermore, the control module 5 periodically reads the DC level output by the detector 22 and compares it with the preset target power range. When it is detected that the power deviates from the target range, the control module 5 starts tuning. The first thing to do is preliminary adjustment. The control module 5 quickly adjusts the gain by adjusting the gate bias voltage Vg of the power amplifier PA and the driver amplifier DA. For example, when the ambient temperature drops and the device gain increases, which in turn causes the output power to be too high, the control module 5 appropriately reduces Vg, reduces the gain of the power amplifier, and quickly returns the output power to the target range; conversely, when the ambient temperature rises or the device ages and causes the gain to decrease, the control module 5 increases Vg, enhances the power amplification capability, and ensures that the output power is close to the target value. Since the adjustment response speed of the bias voltage is extremely fast, the preliminary adjustment process can usually control the power deviation within a small range in a short time.

[0069] After completing the preliminary adjustment, if it is detected that there is still a slight deviation of 1-2% in the output power, the system will enter the fine adjustment stage. In this stage, the control module 5 adjusts the output impedance by changing the capacitor combination of the variable capacitor array matching network 4 to achieve precise matching. The variable capacitor array matching network 4 adopts a six-bit binary weighted structure and is composed of high-Q value MIM capacitors and switch tubes. The control module 5 gradually changes the capacitor combination according to the lookup table or algorithm (such as binary search or incremental trial) to optimize the equivalent capacitance value C of the output end. eq , thereby adjusting the output impedance Z OUT In the millimeter wave frequency band, accurate impedance matching can not only improve power transmission efficiency, but also effectively reduce reflection loss and ensure the reflection coefficient S 11 ≤-15dB. As the state of the capacitor array changes, the DC level output by the detector 22 also changes accordingly, and the control module 5 makes real-time judgments through continuous feedback and finally locks in the best matching point. It should be understood that the control module 5 can also change the capacitor combination of the variable capacitor array matching network 4 through algorithms such as binary search and incremental trial.

[0070] The present invention uses a two-stage closed-loop adjustment mechanism that combines preliminary adjustment with fine adjustment, so that the millimeter wave transmitter can automatically adapt to variable conditions such as drastic temperature changes and load impedance shifts. In actual work, when the ambient temperature continues to fluctuate or the load drifts, the control module 5 will repeat the above adjustment process to ensure that the output power is always stable within the target range and meets the system performance requirements.

[0071] It should be noted that the control module 5 has a built-in lookup table generated based on simulation and experimental results. The lookup table records the optimal matching state of each capacitor combination under different temperature and load conditions and the corresponding bias voltage value. During system operation, the control module 5 can quickly load the initial configuration through the lookup table, significantly reducing the adjustment time, and record the new optimal state after further optimization for subsequent reference. This mechanism not only improves the adjustment efficiency, but also provides data support for dynamic performance optimization in long-term operation.

[0072] In summary, the preliminary gain adjustment is achieved through the rapid preliminary adjustment of the bias voltage, and the impedance matching is optimized through fine tuning of the variable capacitor array matching network 4, so that the millimeter wave transmitter can maintain efficient and stable output power under complex environmental conditions, providing reliable technical support for applications such as 5G millimeter wave communications, radar and high-frequency sensing.

[0073] Another aspect of the present invention provides a design method for a millimeter wave transmitter capable of dynamically adjusting output power, which specifically comprises the following steps:

[0074] S10: Determine the target performance parameters of the transmitter, including:

[0075] Working frequency f;

[0076] Output power P OUT ∈[15,30]dBm;

[0077] Reflection coefficient S 11 ≤-15dB;

[0078] Output impedance range Z OUT ∈[Z MIN ,Z MAX ]Ω;

[0079] S20: Calculate the output impedance range Z based on the target performance parameters OUT and the step value ΔC of the variable capacitor array matching network 4;

[0080] S30: Use simulation tools to perform parameter traversal on frequency, temperature and load conditions, generate a lookup table, and record the optimal bias voltage V under each condition. bias And the equivalent capacitance C eq Configuration;

[0081] S40: Enter the lookup table into the control module 5 for adjusting the bias voltage V during the operation of the transmitter bias And the equivalent capacitance C eq Configuration.

[0082] The calculation in step S20 is based on the operating frequency range f∈[24,30] GHz. More specifically, in step S10, the operating frequency f=28 GHz and the output impedance range Z OUT ∈[30,70]Ω.

[0083] Furthermore, step S20 further includes the following steps:

[0084] S21: Calculate the output impedance range Z OUT , output impedance range Z OUT The adjustment is achieved through the variable capacitor array matching network 4, and the output impedance and equivalent capacitance satisfy the following relationship:

[0085]

[0086] Among them, the equivalent capacitance C of the variable capacitor array matching network 4 eq Satisfies the following relationship:

[0087]

[0088] In the formula, S i is the conduction state of the switch tube corresponding to the i-th capacitor, which is 1 when it is on and 0 when it is off; C i is the capacitance value of the i-th capacitor;

[0089] S22: Design variable capacitor array matching network 4. The capacitor array is arranged in binary weighted order. The minimum capacitance value C unit It is equal to the value of the step value ΔC and satisfies the following relationship:

[0090]

[0091] Where N is the number of bits in the capacitor array.

[0092] The different temperature conditions in step S30 are T = -40°C, T = 0°C, T = 25°C and T = 125°C, and the different load impedance conditions are Z load ∈[30,70]Ω.

[0093] The design method of the present invention is described below with a specific embodiment:

[0094] S10: Clarify the target performance parameters of the millimeter wave transmitter to be designed, the operating frequency f = 28GHz, which is an important frequency for millimeter wave communication, and the output power P OUT =[15,30]dBm, reflection coefficient S 11 ≤-15dB, output impedance range Z OUT ∈[30,70]Ω;

[0095] S20: Calculate the equivalent capacitance C of the variable capacitor array matching network 4 based on the target output impedance range and operating frequency. eq The range and step value ΔC.

[0096] According to the impedance matching formula Take Z OUT The model value is obtained Then get By Z OUT ∈[30,70]Ω, calculate the equivalent capacitance C eq Capacitance range:

[0097] When Z OUT =70Ω,

[0098] When Z OUT =30Ω,

[0099] Therefore, the equivalent capacitance range of the variable capacitor array matching network 4 is C eq ∈[8.99,18.94]fF. Furthermore, the number of bits of the variable capacitor array matching network 4 is six, and the minimum step value is This step value ensures that the variable capacitor array matching network 4 can achieve accurate adjustment of the output impedance, while the circuit structure is simple and meets the requirements of the transmitter power range and reflection coefficient.

[0100] S30: Using simulation tools, the four temperature nodes of T = -40 ° C, T = 0 ° C, T = 25 ° C and T = 125 ° C and the load impedance range Z load ∈[30,70]Ω to perform parameter traversal and test the output power and reflection coefficient corresponding to each combination of the capacitor array one by one. OUT and the reflection coefficient S 11 Target required bias voltage V bias and capacitance C eq The best combination is recorded to form a lookup table.

[0101] In the simulation, the performance changes under various combinations are checked by adjusting the bias voltage and capacitance value. For example, as the temperature increases, the adjustment range of the capacitance value will increase accordingly to compensate for the offset of the load impedance and ensure that the reflection coefficient S 11 ≤-15dB and power stable.

[0102] S40: Enter the generated lookup table into the control module 5, which may be an MCU or a programmable integrated circuit FPGA with a table lookup function. During the operation of the system, the control module 5 adjusts the bias voltage V according to the real-time feedback signal. biasThe output power is adjusted by combining with the capacitor array of the variable capacitor array matching network 4. When the output power deviates from the target value, the control module 5 quickly switches to the corresponding optimal configuration in the lookup table to achieve dynamic adjustment of the output power and impedance.

[0103] For example, when the system is at T = 25 ° C and the load impedance is 50□Ω, the control module 5 quickly retrieves the bias voltage V through the lookup table. bias = 0.8V and capacitance value combination C eq =12.3fF configuration to make the system performance meet the target requirements.

[0104] Through the above steps, a design method for a millimeter-wave transmitter with dynamically adjustable output power is realized, which solves the problem that traditional fixed matching networks and bias designs are difficult to adapt to environmental changes, and can maintain efficient and stable power output under different frequency, temperature and load conditions.

[0105] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A millimeter wave transmitter capable of dynamically adjusting output power, comprising an amplification module and a fixed matching network, wherein an input signal is amplified by the amplification module and then input into the fixed matching network, and a transmitting antenna is arranged at the output end of the fixed matching network, characterized in that: Also includes A power detection module, arranged at the input end of the transmitting antenna, for real-time monitoring of the output power and generating a feedback signal; A voltage bias module, connected to the amplification module, for adjusting the bias voltage of the amplification module and performing preliminary adjustment on the output power of the transmitter; A variable capacitor array matching network is arranged between the output terminal and the ground terminal of the fixed matching network, and includes a plurality of capacitors connected in parallel, each of which is respectively connected in series with a switch tube. When the plurality of switch tubes are turned on and off, different capacitor combinations are formed to change the output impedance, thereby finely adjusting the output power. The control module is connected to the power detection module, the voltage bias module and the variable capacitor array matching network, and is used to receive the feedback signal and adjust the bias voltage of the amplification module and the capacitance combination of the variable capacitor array matching network according to the feedback signal.

2. A millimeter wave transmitter capable of dynamically adjusting output power as claimed in claim 1, characterized in that: The variable capacitor array matching network includes six high-Q MIM capacitors connected in parallel, and the capacitor units are arranged in binary weighted manner.

3. A millimeter wave transmitter capable of dynamically adjusting output power as claimed in claim 2, characterized in that: The dynamic adjustment range of the variable capacitor array matching network covers the output impedance Z OUT ∈[30, 70]Ω, its equivalent capacitance C eq ∈[8.99, 18.94]fF, step value ΔC=0.158fF.

4. A millimeter wave transmitter capable of dynamically adjusting output power as claimed in claim 1, characterized in that: The power detection module includes a directional coupler and a detector. The input end of the directional coupler is connected to a fixed matching network, the output end is connected to an antenna, the coupling end is connected to the detector, and a load is arranged at the isolation end. The detector is a Schottky detection diode, and the output end of the detector is connected to the control module.

5. A millimeter wave transmitter capable of dynamically adjusting output power as claimed in claim 4, characterized in that: The directional coupler is a microstrip line structure with a coupling ratio of -15dB. Its output port is connected to a 50Ω matching resistor to improve directivity and isolation.

6. A design method for a millimeter wave transmitter capable of dynamically adjusting output power, applied to the millimeter wave transmitter as claimed in any one of claims 1 to 5, characterized in that: The following steps are involved: S10: Determine the target performance parameters of the transmitter, including: Working frequency f; Output power P OUT ∈[15,30]dBm; Reflection coefficient S 11 ≤-15dB; Output impedance range Z OUT ∈[Z MIN , Z MAX ]Ω; S20: Calculate the output impedance range Z based on the target performance parameters OUT and the step value ΔC of the variable capacitor array matching network; S30: Use simulation tools to perform parameter traversal on frequency, temperature and load conditions, generate a lookup table, and record the optimal bias voltage V under each condition. bias and equivalent capacitance C eq Configuration; S40: Enter the lookup table into the control module for adjusting the bias voltage V during transmitter operation. bias and equivalent capacitance C eq Configuration.

7. A millimeter wave transmitter capable of dynamically adjusting output power as claimed in claim 6, characterized in that: In step S10, the operating frequency f=28 GHz, the output impedance range Z OUT ∈[30,70]Ω.

8. A millimeter wave transmitter capable of dynamically adjusting output power as claimed in claim 7, characterized in that: Step S20 further includes the following steps: S21: Calculate the output impedance range Z OUT , output impedance range Z OUT The adjustment is achieved through a variable capacitor array matching network, and the output impedance and equivalent capacitance satisfy the following relationship: Among them, the equivalent capacitance C of the variable capacitor array matching network eq Satisfies the following relationship: In the formula, S i is the conduction state of the switch tube corresponding to the i-th capacitor, which is 1 when it is on and 0 when it is off; C i is the capacitance value of the i-th capacitor; S22: Design a variable capacitor array matching network. The capacitor array is arranged in binary weighted order. The minimum capacitance value C unit It is equal to the value of the step value ΔC and satisfies the following relationship: Where N is the number of bits in the capacitor array.

9. A millimeter wave transmitter capable of dynamically adjusting output power as claimed in claim 8, characterized in that: In step S30, the different temperature conditions are T = -40 ° C, T = 0 ° C, T = 25 ° C and T = 125 ° C, and the different load impedance conditions are Z load ∈[30,70]Ω.

10. A millimeter wave transmitter capable of dynamically adjusting output power as claimed in claim 6, characterized in that: The calculation in step S20 is based on the operating frequency range f∈[24,30] GHz.

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