Millimeter wave receiver capable of dynamically configuring input impedance and design method thereof

Abstract

The invention provides a millimeter wave receiver capable of dynamically configuring input impedance and a design method of the millimeter wave receiver, and relates to the technical field of radio frequency and millimeter wave communication.The receiver comprises a receiving antenna, a dynamic input impedance matching loop and a signal processing module, the dynamic input impedance matching loop comprises a fixed matching network, a variable capacitor array matching network, a detection module and a control module, and the matching efficiency and gain can be optimized by adjusting the input impedance range and the equivalent capacitance; the signal processing module comprises a low-noise amplifier, a frequency mixer and a low-pass filter, and dynamic optimization of a noise coefficient and receiving gain is achieved by adjusting a gain control pin and grid bias voltage. The invention further provides a design method, the optimal parameter configuration is calculated by constructing the multi-objective optimization model F, and the system performance is adjusted in real time. The method can be widely applied to millimeter wave communication, high-frequency radar and other high-performance receiving systems, and has the technical advantages of accuracy, high efficiency and stability.

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 receiver capable of dynamically configuring input impedance and a design method thereof. Background Art

[0002] As a key component in wireless communication systems, the main task of the receiver is to receive the RF signal transmitted by the antenna, and after low-noise amplification, mixing, filtering and other processing, output the intermediate frequency or baseband signal suitable for subsequent signal processing. In millimeter wave communications, the receiver needs to cope with complex challenges such as high signal frequency, large bandwidth, and severe path loss. Especially in high-frequency and high-speed applications such as 5G millimeter wave communications and millimeter wave radars, the performance requirements for the receiver are more stringent.

[0003] In order to achieve efficient signal reception, the receiver front end is usually designed as a fixed input impedance and fixed bias structure. However, in practical applications, the fixed design method has significant limitations. For example, the impedance of the receiving antenna will drift due to the working environment and manufacturing process deviation, which will reduce the impedance matching efficiency of the receiver input and lead to signal energy loss. In addition, as the communication frequency increases, the signal attenuation becomes more serious, which puts higher requirements on the impedance matching and signal sensitivity of the receiver input.

[0004] The existing receivers still face at least the following problems during signal processing:

[0005] (1) Insufficient input impedance matching efficiency: Due to factors such as antenna impedance drift and frequency change, the impedance matching efficiency at the receiver input is prone to decrease. This not only causes the signal energy to be unable to be effectively transmitted, but also significantly reduces the receiving sensitivity, affecting the overall performance of the system.

[0006] (2) Difficulty in optimizing noise figure: The noise performance of the low noise amplifier at the front end of the receiver directly affects the sensitivity of the receiver. In the existing fixed bias design, the noise optimization capability of the LNA is limited, and it is difficult to maintain a low noise figure under different environmental conditions, thus limiting the signal capture capability of the receiver.

[0007] (3) Unstable receiving gain control: In scenarios where the received signal strength varies greatly, the receiver gain needs to be dynamically adjusted according to the signal conditions. However, existing receivers have a response delay problem during gain control and cannot quickly adapt to different input signals, resulting in fluctuations in the received signal quality.

[0008] (4) Slow dynamic adjustment response speed: Dynamic input impedance matching usually relies on a lookup table to adjust the configuration of the variable capacitor array to achieve matching optimization. However, the lookup table generation process is complex and difficult to respond in real time when the environment changes rapidly, which cannot meet the dynamic adaptability requirements of high-speed communication systems for receivers. Summary of the invention

[0009] 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 receiver capable of dynamically configuring input impedance and a design method thereof, adopting the following technical solutions:

[0010] On one hand, the present invention provides a millimeter wave receiver capable of dynamically configuring input impedance, comprising: a receiving antenna, a dynamic input impedance matching loop and a signal processing module, wherein the receiving antenna is used to receive electromagnetic wave signals and convert them into electrical signals and transmit them to the dynamic input impedance matching loop, and the output end of the dynamic input impedance matching loop is connected to the signal processing module;

[0011] The dynamic input impedance matching loop includes a fixed matching network, a variable capacitance array matching network, a detection module and a control module. The input end of the fixed matching network is provided with the receiving antenna, and the output end is connected to the variable capacitance array matching network. The variable capacitance array matching network is controlled by the control module and connected to the signal processing module through the detection module.

[0012] The signal processing module includes a low noise amplifier, a mixer and an active low pass filter;

[0013] The input end of the low noise amplifier is connected to the output end of the dynamic input impedance matching loop, and the low noise amplifier is provided with a bias voltage control pin;

[0014] The above active low-pass filter is provided with a gain control pin for adjusting the gain and bandwidth of the output signal;

[0015] The control module is electrically connected to the low noise amplifier and the active low pass filter, and is used to control the bias voltage control pin and the automatic gain control pin according to the feedback signal.

[0016] As a further improvement, the detection module includes a directional coupler and a detector, the input end of the directional coupler is connected to the variable capacitor array matching network, the output end is connected to the low noise amplifier, the coupling end is connected to the detector, and the isolation end is provided with a load; the detector is a Schottky detection diode, and its output end is connected to the control module.

[0017] As a further improvement, the control module is a microcontroller unit or a field programmable gate array, which is used to periodically read the feedback signal of the detector and adjust the capacitance combination of the variable capacitance matrix matching network, the bias voltage of the low noise amplifier and the gain of the active low-pass filter according to the feedback signal.

[0018] As a further improvement, the above-mentioned variable capacitor array matching network includes multiple high-Q value MIM capacitors connected in parallel, each capacitor is connected in series with a switching tube, the conduction state of the above-mentioned switching tube is controlled by the above-mentioned control module, and dynamic adjustment of the input impedance can be achieved through different capacitor combinations. The capacitor units are arranged in binary weighted manner.

[0019] The present invention further provides a design method for a millimeter wave receiver capable of dynamically configuring input impedance, which is applied to any of the millimeter wave receivers described above, and comprises the following steps:

[0020] S10: Determine the target performance parameters of the receiver, including

[0021] Working frequency f;

[0022] System noise factor NF;

[0023] Receive gain G RX ;

[0024] Matching efficiency η match ;

[0025] Input impedance range Z IN ∈[Z MIN ,Z MAX ]Ω;

[0026] S20: Calculate input impedance range Z based on target performance parameters IN , the equivalent capacitance C of the variable capacitor array matching network eq and step value ΔC;

[0027] S30: Construct a multi-objective optimization model F, which is defined by the following relationship:

[0028] F=-NF+λ1·G RX +λ2·η match

[0029] Among them, λ1 and λ2 are the receiving gain G RX and matching efficiency η match The weight factor of

[0030] S40: Adjust the equivalent capacitance C of the variable capacitor array matching network eq , the gate bias voltage of the noise amplifier V biasAs well as the gain of the active low-pass filter, the model F is dynamically optimized.

[0031] As a further improvement, in step S30, the default value of λ1 is 0.7, and the default value of λ2 is 0.3.

[0032] As a further improvement, in step S10, the system noise coefficient NF < 7dB; the receiving gain 55dB <G RX ≤65dB; matching efficiency η match ≥90%.

[0033] As a further improvement, the control module adjusts the following parameters by calculating the value of the multi-objective optimization model F in real time:

[0034] When the system noise figure exceeds the target range, increase the gate bias voltage V of the noise amplifier. bias Reduce noise;

[0035] When the receiving gain does not meet the target range, the gain of the active low-pass filter is adjusted through the gain control pin;

[0036] When the matching efficiency decreases, adjust the equivalent capacitance C of the variable capacitor array matching network. eq Improve matching efficiency.

[0037] As a further improvement, step S20 further includes the following steps:

[0038] S21: Calculate the input impedance range Z IB , input impedance range Z IN The adjustment is achieved through a variable capacitor array matching network, and the output impedance and equivalent capacitance satisfy the following relationship:

[0039]

[0040] Among them, the operating frequency f and the input impedance Z IN The equivalent capacitance C of the variable capacitor array matching network is monitored in real time or preset by the receiver. eq Satisfies the following relationship:

[0041]

[0042] 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; N is the number of bits of the capacitor array;

[0043] S22: Design a variable capacitor array matching network. The capacitor array is arranged in binary weighted order. The minimum capacitance value C unitIt is equal to the value of the step value ΔC and satisfies the following relationship:

[0044]

[0045] As a further improvement, in the above step S10, the above operating frequency f=28GHz, the input impedance Z IN ∈[30,70]Ω, equivalent capacitance C of the variable capacitor array matching network eq ∈[8.99,18.94]fF, step value ΔC=0.158fF.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] First, the present invention sets a dynamic input impedance matching loop in the receiver, which includes a variable capacitor array matching network, a directional coupler and a control module. By real-time monitoring of the input signal power and impedance deviation, the control module is used to dynamically adjust the equivalent capacitance of the variable capacitor array to optimize the impedance matching efficiency of the input end. The present invention realizes dynamic matching of the input impedance through the above structure, effectively improving the signal energy transmission efficiency and receiving sensitivity of the receiver.

[0048] Secondly, the present invention introduces a dynamic gate bias adjustment mechanism into the low-noise amplifier of the receiver. The control module adjusts the gate bias voltage of the low-noise amplifier according to the noise coefficient deviation signal detected in real time, so that the low-noise amplifier can maintain a low noise coefficient under different conditions, effectively solving the problem of limited noise coefficient optimization and significantly improving the sensitivity and signal capture capability of the receiver.

[0049] Thirdly, the present invention controls the gain control pin in the active low-pass filter, and the control module adjusts the gain level of the active low-pass filter in real time, which can quickly achieve gain adjustment under different signal conditions, ensuring that the receiver can still maintain a stable receiving gain when the signal strength changes rapidly, and effectively solving the problem of gain response hysteresis of traditional receivers.

[0050] Fourthly, the present invention introduces a multi-objective optimization model F in the dynamic input impedance matching loop, and through the multi-objective optimization model F = -NF + λ1·G RX +λ2·η match The comprehensive performance of system noise figure, receiving gain and matching efficiency is optimized in real time, which can quickly respond to changes in the working environment without relying on complex lookup table generation process, thereby improving the dynamic response speed and matching accuracy of the receiver. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] 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.

[0052] Figure 1 It is a schematic diagram of the structure of the millimeter wave receiver in the present invention;

[0053] Figure 2 A schematic diagram of the structure of a low noise amplifier circuit according to an embodiment of the present invention;

[0054] Figure 3 A schematic diagram of the structure of a mixer circuit according to an embodiment of the present invention;

[0055] Figure 4 A schematic diagram of the structure of an active low-pass filter circuit according to an embodiment of the present invention;

[0056] Figure 5 A schematic diagram of a variable capacitor array matching network structure according to an embodiment of the present invention;

[0057] Figure 6 A schematic diagram of the structure of a directional coupler according to an embodiment of the present invention;

[0058] Figure 7 FIG. 1 is a schematic diagram of the structure of a detector according to an embodiment of the present invention.

[0059] Reference numerals:

[0060] 1-receiving antenna; 2-dynamic input impedance matching loop; 3-signal processing module;

[0061] 21-detection module; 22-control module; 23-detection module;

[0062] 211-directional coupler; 212-detector;

[0063] 211a-input port; 211b-output port; 211c-coupling port; 211d-isolation port;

[0064] 212a-detector matching network; 212b-rectifier device; 212c-low-pass filter;

[0065] L1-fixed matching network; L2-variable capacitor array matching network; LNA-low noise amplifier; Vbias-bias voltage control pin; Mixer-mixer; LPF-active low-pass filter; AGC-gain control pin. DETAILED DESCRIPTION

[0066] 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:

[0067] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. 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 should not be understood as limiting the present invention.

[0068] like Figure 1 As shown, on the one hand, the present application provides a millimeter wave receiver with dynamically configurable input impedance, including: a receiving antenna 1, a dynamic input impedance matching loop 2 and a signal processing module 3. The receiving antenna 1 serves as a front-end component of the receiver, and is responsible for capturing millimeter wave electromagnetic signals in the external environment, converting them into electrical signals, and then transmitting them to the dynamic input impedance matching loop 2.

[0069] Specifically, the dynamic input impedance matching loop 2 is mainly used to solve the impedance matching problem between the antenna and the receiver front-end circuit. Since millimeter wave signals have extremely high requirements for impedance matching, even a small impedance deviation will lead to increased signal reflection loss, thereby significantly reducing the receiving efficiency. Figure 1 As shown, the dynamic input impedance matching loop 2 includes a fixed matching network L1, a variable capacitor array matching network L2, a detection module 21 and a control module 22. The input end of the fixed matching network L1 is provided with the above-mentioned receiving antenna 1, and the output end is connected to the variable capacitor array matching network L2. The variable capacitor array matching network L2 is controlled by the control module 22 and is connected to the signal processing module 3 through the detection module 21.

[0070] like Figure 1 As shown, the output end of the dynamic input impedance matching loop 2 is connected to the signal processing module 3 .

[0071] like Figure 1 As shown, the signal processing module 3 includes a low noise amplifier LNA, a mixer and an active low pass filter LPF; wherein the input end of the low noise amplifier LNA is connected to the output end of the dynamic input impedance matching loop 2, and the low noise amplifier LNA is provided with a bias voltage control pin Vbias; the active low pass filter LPF is provided with a gain control pin AGC for adjusting the gain of the output signal.

[0072] like Figure 2As shown in the figure, the low noise amplifier LNA is a key module in the receiver signal chain, and its design is to provide high gain, low noise and good linear performance. The input stage of the low noise amplifier LNA adopts a common source structure with a source-stage degeneration inductor, in which the source of the transistor M1 is connected to the ground through the degeneration inductor L12, and the gate is connected to the input RF signal through the input capacitor C11. The subsequent amplifier stage is cascaded by three-stage common source and common gate structures, specifically including transistors M12, M13, M14 and their corresponding LC resonant networks. The characteristic of this structure is that an LC resonant network is configured at the input end of each stage, and these networks are tuned to the center frequency of the millimeter wave band (such as 28GHz) to maximize gain and minimize noise within the target frequency range. At the same time, due to the broadband characteristics of the common source and common gate structure, it can provide good gain and stability over a wide frequency range.

[0073] Furthermore, the bias circuit provides an appropriate DC bias voltage through Vbias1 and Vbias2 to make each amplifier transistor operate at the optimal operating point to ensure that the linearity, gain and noise performance of the amplifier meet the design requirements. Vbias1 mainly provides the bias level for the first-stage common source structure, while Vbias2 provides independent bias control for the subsequent common source and common gate cascade. By dynamically adjusting Vbias1 and Vbias2, real-time optimization of gain and noise can be achieved in actual operation to adapt to environmental changes. The output end of the low noise amplifier LNA is composed of a resonant network L16-C19 and a buffer capacitor C110, which is used to transmit the amplified signal to the mixer Mixer. The high-Q inductor and capacitor form a resonant cavity at the output end, which can filter out high-frequency noise and ensure that the output signal has the best bandwidth and gain at the center frequency.

[0074] like Figure 3 The schematic diagram of the mixer circuit structure shown in FIG. adopts the Gilbert unit topology and consists of a transconductance stage and a switch stage. When the low noise amplifier LNA outputs the RF signal RF and the local oscillation signal LO is input, the transistor array inside the mixer is alternately turned on and off to convert the RF signal spectrum to the IF port output to realize the down-conversion process. The IF signal after down-conversion by the mixer enters the active low-pass filter LPF for bandwidth and gain adjustable processing. The filter is composed of an active operation unit (such as OTA), a variable resistor and a capacitor network, which can be dynamically adjusted by a controller to adapt the filtering characteristics to different communication standards and working conditions.

[0075] like Figure 4The circuit structure diagram of the active low-pass filter shown in FIG. 1 is composed of a feedback network consisting of an operational amplifier, a resistor array and a variable capacitor. The controller can adjust the on-state of the MOS tube switch in the resistor array and the capacitor array to change the cutoff frequency and gain of the filter. The final output IF signal is filtered and amplified within a suitable bandwidth to meet the subsequent demodulation or signal processing requirements.

[0076] In a specific embodiment, the control module 22 is electrically connected to the low noise amplifier LNA and the active low pass filter LPF, and the control module 22 controls the bias voltage control pin Vbias and the gain control pin AGC according to the feedback signal, that is, adjusts the bias voltage of the low noise amplifier LNA and the gain of the active low pass filter LPF.

[0077] like Figure 1 , Figure 6 and Figure 7 As shown, the detection module 21 includes a directional coupler 211 and a detector 212. Figure 6 , the directional coupler 211 is usually a four-port device, including an input port 211a, an output port 211b, a coupling port 211c and an isolation port 211d. Specifically, the input port 211a of the directional coupler 211 is connected to the variable capacitor array matching network L2, the output port 211b is connected to the low noise amplifier LNA, the coupling port 211c is connected to the detector 212, and the isolation port 211d is provided with a load; since a pair of adjacent strip lines are designed in the directional coupler 211, part of the electromagnetic energy is induced in the coupling line through the electromagnetic field coupling, and the coupling signal is output from the coupling port 211c. The isolation port 211d is connected to the matching load to ensure that the coupler has good isolation characteristics in the reverse phase direction. Under millimeter waves, the directional coupler 211 generally adopts a microstrip line or a coplanar waveguide transmission line structure, and the line width, spacing, and length are optimized 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 211d is usually connected to a 50Ω matching resistor to ensure isolation and reduce the impact of reverse reflection on the main circuit.

[0078] Furthermore, the detector 212 is a Schottky detector diode, and its output end is connected to the control module 22. The detector 212 module is responsible for converting the millimeter wave radio frequency signal from the directional coupler 211 into a DC level for the controller to read and determine the power state. Figure 7 In the illustrated embodiment, the detector 212 is composed of a detector matching network 212a, a rectifier device 212b, and a low-pass filter 212c.

[0079] In some embodiments, the control module 22 is a microcontroller unit or a field programmable gate array, which is used to periodically read the feedback signal of the detector 212 and adjust the capacitance combination of the variable capacitance matrix matching network, the bias voltage of the low noise amplifier LNA and the gain of the active low pass filter LPF according to the feedback signal.

[0080] like Figure 5 As shown, the variable capacitor array matching network L2 includes multiple high-Q MIM capacitors connected in parallel, each capacitor is connected in series with a switch tube, and the conduction state of the switch tube is controlled by the control module 22 to achieve dynamic adjustment of the input impedance through different capacitor combinations. The capacitor units are arranged in binary weighted manner.

[0081] 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 C, 2C, 4C, 8C, 16C, and 32C. The equivalent capacitance value of the variable capacitor array matching network L24 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.

[0082] More specifically, the dynamic adjustment range of the variable capacitor array matching network L2 covers the output impedance Z OUT ∈[30,70]Ω, its equivalent capacitance C eq ∈[8.99,18.94]fF, step value ΔC=0.158fF.

[0083] The present invention further provides a design method for a millimeter wave receiver capable of dynamically configuring input impedance, which is applied to any of the millimeter wave receivers described above and comprises the following steps:

[0084] S10: Determine the target performance parameters of the receiver, including operating frequency f; system noise factor NF; receiving gain G RX ; Matching efficiency η match ; Input impedance range Z IN ∈[Z MIN ,Z MAX ]Ω.

[0085] This step is the starting point of the design process and clarifies the design goals. The above parameters are specifically:

[0086] System noise factor NF: The basic requirement of a low-noise receiver. System noise directly affects the quality and sensitivity of the received signal.

[0087] Receive gain G RX : Provide sufficient gain to compensate for signal attenuation;

[0088] Matching efficiency η match :Ensure the matching between the antenna and the receiver input impedance, thereby reducing reflection loss and improving signal reception efficiency;

[0089] Input impedance Z IN : Make adaptive adjustments according to different conditions.

[0090] In a specific embodiment, the operating frequency f=28 GHz, the input impedance Z IN ∈[30,70]Ω, system noise factor NF≤7dB, receiving gain G RX ∈[55,65]dB, matching efficiency η match ≥90%.

[0091] S20: Calculate input impedance range Z based on target performance parameters IN , the equivalent capacitance C of the variable capacitor array matching network L2 eq and step value ΔC.

[0092] Further including:

[0093] S21: Calculate the input impedance range Z IN , input impedance range Z IN The adjustment is achieved through the variable capacitor array matching network L2, and the output impedance and equivalent capacitance satisfy the following relationship:

[0094]

[0095] Among them, the operating frequency f and the input impedance Z IN The equivalent capacitance C of the variable capacitor array matching network L2 is monitored in real time or preset by the receiver. eq Satisfies the following relationship:

[0096]

[0097] 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; N is the number of bits of the capacitor array;

[0098] S22: Design a variable capacitor array matching network L2. The capacitor array is arranged in binary weighted order. The minimum capacitance value C unitIt is equal to the value of the step value ΔC and satisfies the following relationship:

[0099]

[0100] S30: Construct a multi-objective optimization model F, which is defined by the following relationship:

[0101] F=-NF+λ1·G RX +λ2·η match

[0102] Among them, λ1 and λ2 are the receiving gain G RX and matching efficiency η match The weight factor can be adjusted as needed in different scenarios. In a specific embodiment, the default value of λ1 is 0.7, and the default value of λ2 is 0.3.

[0103] This step achieves overall performance optimization by constructing a multi-objective optimization model F to comprehensively weigh the noise figure, gain, and matching efficiency. The role of the optimization model includes quantifying performance trade-offs. Specifically, different receiver performance parameters may conflict with each other. For example, reducing the noise figure may lead to a decrease in gain. The multi-objective optimization model F can weigh different performance indicators.

[0104] S40: Adjust the equivalent capacitance C of the variable capacitor array matching network L2 eq , the gate bias voltage of the noise amplifier V bias As well as the gain of the active low-pass filter LPF, the model F is dynamically optimized.

[0105] The control module 22 adjusts the following parameters by calculating the value of the multi-objective optimization model F in real time:

[0106] When the system noise figure exceeds the target range, increase the gate bias voltage V of the noise amplifier. bias Reduce noise; when the receiving gain does not meet the target range, adjust the gain of the active low-pass filter LPF through the gain control pin AGC; when the matching efficiency decreases, adjust the equivalent capacitance C of the variable capacitor array matching network L2 eq Improve matching efficiency.

[0107] The design method of the present invention is described below with a specific embodiment:

[0108] S10: In this embodiment, the receiver operates in the 28 GHz frequency band, and the target parameters are:

[0109] Operating frequency f = 28 GHz;

[0110] Input impedance Z IN ∈[30,70]Ω;

[0111] System noise factor NF≤7dB;

[0112] Receive gain G RX ∈[55,65]dB;

[0113] Matching efficiency η match ≥90%.

[0114] S20: According to the input impedance Z IN ∈[30,70]Ω, and the operating frequency f=28GHz, calculate the equivalent capacitance C of the variable capacitance matrix eq and step value ΔC.

[0115] According to the impedance matching formula Take Z IN The model value is obtained Then get By Z IN ∈[30,70]Ω, calculate the equivalent capacitance C eq Capacitance range:

[0116] When Z IN =70Ω,

[0117] When Z IN =30Ω,

[0118] Therefore, the equivalent capacitance range of the variable capacitor array matching network L2 is C eq ∈[8.99,18.94]fF.

[0119] Furthermore, the number of bits of the variable capacitor array matching network L2 is six, and the minimum step value is This step value ensures that the variable capacitor array matching network L2 can achieve precise adjustment of the output impedance.

[0120] S30: Construct a multi-objective optimization model: F = -NF + λ1·G RX +λ2·η match , where the default value of λ1 is 0.7 and the default value of λ2 is 0.3.

[0121] S40: Dynamic optimization and debugging.

[0122] Case 1: The current system noise figure NF = 7.5dB (the target is NF ≤ 7dB). At this time, the noise figure needs to be reduced and the gate bias voltage V of the low noise amplifier LNA needs to be increased. bias , to increase the transconductance g of the transistor m :

[0123]

[0124] Increase V bias Can increase the gate-source voltage V gs , thereby increasing the overdrive voltage V ov , further increasing the drain current I DS , thereby increasing the transconductance g m , and a larger transconductance can effectively reduce the noise figure of the low noise amplifier LNA.

[0125] Case 2: Current receiving gain G RX =53dB (target is G RX ∈[55,65]dB), the gain needs to be increased.

[0126] Adjust the gain control pin AGC to increase the gain of the active low-pass filter LPF. Assuming the current AGC=1.2V, adjust AGC=1.5V, the corresponding filter gain is increased from 10dB to 12dB. At the same time, increase the gate bias voltage V of the low noise amplifier LNA bias , the gain is increased by about 2dB.

[0127] After adjustment, the receiving gain G RX =57dB, entering the target range.

[0128] Case 3: Current matching efficiency η match =85% (target is η match ≥90%), in this case, the input impedance matching needs to be adjusted.

[0129] The detection module 21 monitors the matching efficiency η in real time match , and calculates a new adaptation equivalent capacitance C through the control module 22 eq . Assume that C eq =10.5fF, by changing the switch state of the variable capacitor array matching network L2, changing C eq is 11.2fF, and the adjusted η match =92%, meeting the target requirements.

[0130] In this embodiment, the control module 22 monitors NF, G in real time. RX , η match The optimal adjustment scheme is automatically calculated according to the multi-objective optimization model F, and the receiver can still maintain high efficiency performance in complex environments and meet the target parameter requirements.

[0131] 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 receiver with dynamically configurable input impedance, characterized in that: include: A receiving antenna, a dynamic input impedance matching loop and a signal processing module, wherein the receiving antenna is used to receive electromagnetic wave signals and convert them into electrical signals for transmission to the dynamic input impedance matching loop, and the output end of the dynamic input impedance matching loop is connected to the signal processing module; The dynamic input impedance matching loop includes a fixed matching network, a variable capacitance array matching network, a detection module and a control module. The input end of the fixed matching network is provided with the receiving antenna, and the output end is connected to the variable capacitance array matching network. The variable capacitance array matching network is controlled by the control module and connected to the signal processing module through the detection module. The signal processing module includes a low noise amplifier, a mixer and an active low pass filter; The input end of the low noise amplifier is connected to the output end of the dynamic input impedance matching loop, and the low noise amplifier is provided with a bias voltage control pin; The active low-pass filter is provided with a gain control pin for adjusting the gain and bandwidth of the output signal; The control module is electrically connected to the low noise amplifier and the active low pass filter, and is used to control the bias voltage control pin and the automatic gain control pin according to the feedback signal.

2. A millimeter wave receiver with dynamically configurable input impedance as claimed in claim 1, characterized in that: The detection module includes a directional coupler and a detector, the input port of the directional coupler is connected to the variable capacitance array matching network, the output port is connected to the low noise amplifier, the coupling port is connected to the detector, and the isolation port is provided with a load; the detector is a Schottky detection diode, and its output end is connected to the control module.

3. A millimeter wave receiver with dynamically configurable input impedance as claimed in claim 2, characterized in that: The control module is a microcontroller unit or a field programmable gate array, which is used to periodically read the feedback signal of the detector and adjust the capacitance combination of the variable capacitance matrix matching network, the bias voltage of the low noise amplifier and the gain of the active low pass filter according to the feedback signal.

4. A millimeter wave receiver with dynamically configurable input impedance as claimed in claim 1, characterized in that: The variable capacitor array matching network includes a plurality of high-Q MIM capacitors connected in parallel, each capacitor is connected in series with a switch tube, the conduction state of the switch tube is controlled by the control module, and dynamic adjustment of the input impedance can be achieved through different capacitor combinations. The capacitor units are arranged in binary weighted manner.

5. A design method for a millimeter wave receiver capable of dynamically configuring input impedance, applied to the millimeter wave receiver according to any one of claims 1 to 4, characterized in that: The following steps are involved: S10: Determine the target performance parameters of the receiver, including Working frequency f; System noise factor NF; Receive gain G RX ; Matching efficiency η match ; Input impedance range Z IN ∈[Z MIN , Z MAX ]Ω; S20: Calculate input impedance range Z based on target performance parameters IN , the equivalent capacitance C of the variable capacitor array matching network eq and step value ΔC; S30: Construct a multi-objective optimization model F, which is defined by the following relationship: F=-NF+λ1·G RX +λ2·η match Among them, λ1 and λ2 are the receiving gain G RX and matching efficiency η match The weight factor of S40: Adjust the equivalent capacitance C of the variable capacitor array matching network eq , the gate bias voltage of the noise amplifier V bias As well as the gain of the active low-pass filter, the model F is dynamically optimized.

6. The method for designing a millimeter wave receiver with dynamically configurable input impedance as claimed in claim 5, characterized in that: In step S30, the default value of λ1 is 0.7, and the default value of λ2 is 0.

3.

7. The method for designing a millimeter wave receiver with dynamically configurable input impedance as claimed in claim 5, characterized in that: In step S10, the system noise factor NF<7dB; the receiving gain is 55dB <G RX ≤65dB; matching efficiency η match ≥90%.

8. The method for designing a millimeter wave receiver with dynamically configurable input impedance as claimed in claim 7, characterized in that: The control module adjusts the following parameters by calculating the value of the multi-objective optimization model F in real time: When the system noise figure exceeds the target range, the gate bias voltage of the noise amplifier is increased to reduce the noise; When the receiving gain does not meet the target range, the gain of the active low-pass filter is adjusted through the gain control pin; When the matching efficiency decreases, adjust the equivalent capacitance C of the variable capacitor array matching network. eq Improve matching efficiency.

9. The method for designing a millimeter wave receiver capable of dynamically configurable input impedance as claimed in claim 5, characterized in that: Step S20 further includes the following steps: S21: Calculate the input impedance range Z IN , input impedance range Z IN 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 operating frequency f and the input impedance Z IN The equivalent capacitance C of the variable capacitor array matching network is monitored in real time or preset by the receiver. 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; N is the number of bits of the capacitor array; 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:

10. The method for designing a millimeter wave receiver capable of dynamically configurable input impedance as claimed in claim 9, characterized in that: In step S10, the operating frequency f=28 GHz, the input impedance Z IN ∈[30, 70]Ω, equivalent capacitance C of the variable capacitor array matching network eq ∈[8.99, 18.94]fF, step value ΔC=0.158fF.

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