RFID electronic tag anti-collision processing system

Abstract

The invention discloses an RFID electronic tag anti-collision processing system, which relates to the technical field of radio frequency identification and comprises an encryption module, a signal processing module and a real-time processing module. The encryption module is used for realizing label identity verification based on a hash function; the signal processing module adopts a mixed anti-collision mechanism combining a time slot ALOHA protocol and a binary tree search algorithm; the real-time processing module comprises a multi-channel parallel processing unit, and each channel is configured with an independent local frequency. According to the RFID electronic tag anti-collision system, the encryption module, the signal processing module and the real-time processing module are combined, the problem of multi-tag collision of the RFID technology in a high-density and dynamic application scene is effectively solved, the encryption module adopts a hash function and an elliptic curve encryption algorithm, safe and efficient verification of tag identities is achieved, and the security and reliability of the RFID electronic tag are improved. The innovative hybrid anti-collision mechanism of the signal processing module is the combination of a slot ALOHA protocol and a binary tree search algorithm.

Description

Technical Field

[0001] The present invention relates to the technical field of radio frequency identification, and more particularly to an RFID electronic tag anti-collision processing system. Background Art

[0002] Radio Frequency Identification (RFID) technology, as a key enabling technology in the Internet of Things field, has been widely applied in scenarios such as logistics warehousing, retail management, intelligent manufacturing, and smart cities. The global RFID market size is expected to exceed $30 billion by 2025, and its core advantage lies in the non-contact rapid identification and data acquisition capabilities. However, as the application scenarios develop towards high density and dynamism, the multi-tag collision problem within the effective range of the reader antenna has become increasingly prominent. Traditional anti-collision technologies are mainly based on basic theories such as the slotted ALOHA protocol and the binary tree search algorithm, and achieve tag identification through time division or coding discrimination. However, in complex electromagnetic environments, large-scale tag groups (more than 1000 tags), and mobile scenarios, there are problems such as a sharp drop in identification efficiency and insufficient communication reliability. Especially in the ultra-high frequency (UHF) band, the superposition of factors such as signal multipath effects and metal environment reflection interference further exacerbates the aliasing collision of tag response signals, resulting in a decrease in system throughput and an increase in the error rate.

[0003] In the prior art, anti-collision algorithms based on static parameters are difficult to adapt to dynamic environmental changes. For example, the number of time slots in the classic ALOHA protocol is fixed, and when the number of tags surges, the collision probability increases exponentially. Measured data shows that when the number of tags exceeds three times the number of time slots, the identification success rate will be lower than 60%. On the other hand, the separate design of the encryption algorithm and the anti-collision mechanism makes it difficult to balance security and efficiency - traditional encryption schemes such as AES-128 can ensure data security, but their computational delay (about 200 μs) significantly slows down the multi-tag response speed. At the same time, the static design of antenna impedance matching cannot cope with the load mutation caused by the concurrent response of multiple tags. In typical scenarios, the voltage standing wave ratio (VSWR) may surge from 1.2 to above 2.0, resulting in a signal power reflection loss of up to 11%. In addition, existing systems lack the dynamic perception ability of context information such as tag priority and spatial location, and it is difficult to meet the differentiated requirements such as the tracking of valuable items in intelligent warehousing and the timeliness management of cold chain logistics. In response to this, we propose an RFID electronic tag anti-collision processing system. Summary of the Invention

[0004] To solve the above technical problems, an RFID electronic tag anti-collision processing system is provided, and this technical solution solves the above problems.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] An RFID electronic tag anti - collision processing system, comprising: an encryption module, a signal processing module and a real - time processing module;

[0007] The encryption module is used to implement tag authentication based on a hash function;

[0008] The signal processing module adopts a hybrid anti - collision mechanism combining the slotted ALOHA protocol and the binary tree search algorithm;

[0009] The real - time processing module includes a multi - channel parallel processing unit, and each channel is configured with an independent local oscillator frequency;

[0010] When the system works, the following steps are executed:

[0011] S1. The reader broadcasts an encrypted activation signal E(t)=A·cos(2πf c t + φ(t)), synchronizes the tags and transmits time - slot parameters. In the formula, E(t) is the encrypted activation signal transmitted by the reader, A is the signal amplitude, f c is the carrier frequency, t is the time, and φ(t) is the encrypted phase - modulation function;

[0012] S2. The tag response signal adopts orthogonal frequency - division multiplexing technology to split the response data for sub - carrier transmission and returns the encrypted data;

[0013] S3. Dynamically schedule the tag response order according to the signal strength and service rules, and establish a dynamic priority queue;

[0014] S4. Monitor the voltage standing - wave ratio (VSWR) in real time through VSWR monitoring. When the VSWR is greater than the preset threshold, trigger the adjustment of the adaptive impedance matching network to optimize the signal transmission quality through impedance matching.

[0015] Preferably, the encryption module includes:

[0016] The key generation unit adopts the elliptic curve encryption algorithm, selects a base point G(x,y) in the prime field GF(p), the private key d ∈ [1,n - 1], and the public key Q = d·G, where p = 2 256 -2 32 -977;

[0017] The tag authentication process executes a three - way handshake protocol:

[0018] The reader sends a challenge value C = H(T1||RND), where C is the challenge value sent by the reader, H is the hash function, T1 is the timestamp, and RND is a 16 - byte random number;

[0019] The tag calculates the response value where R is the response value calculated by the tag, H is the hash function, and K T is the pre - set key of the tag;

[0020] The verification module performs key matching by solving the equation where K′ T is the key solved by the verification module, R is the response value calculated by the tag, C is the challenge value sent by the reader, K DB is the key stored in the database, and ID is the unique identifier of the tag;

[0021] The encrypted communication adopts the AES-CTR mode, and the initial value of the counter CTR = H(T2||ID) mod 2 128 , and the CTR of each frame of data is updated as CTR = CTR + 1, where CTR is the initial value of the counter, T2 is the timestamp, and mod is the modulo operator.

[0022] Preferably, the tag authentication is implemented based on a hash function, and the hash function expression is:

[0023]

[0024] where H is the hash function, ID is the unique identifier of the tag, K is a dynamically generated 128-bit encryption key, T is the timestamp accurate to milliseconds, and SHA256 is the 256-bit version of the Secure Hash Algorithm.

[0025] Preferably, the signal processing module includes:

[0026] The formula for implementing the time slot allocation algorithm is:

[0027] t slot = τ × 2 L-1

[0028] where t slot is the time slot duration, τ is the basic time slot unit, τ = 300 μs is the basic time slot unit, L is the conflict level, and L ∈ [1, 5] is the conflict level;

[0029] The binary search process is executed: when k tag conflicts are detected, the query prefix is split into P0||b, b ∈ {0, 1}, and the recursion depth D satisfies 2 D ≥ k;

[0030] The signal separation adopts MIMO technology, with N t = 4 transmitting antennas and N r = 2 receiving antennas. The channel matrix calculates the precoding matrix W = H H (HH H ) -1 ;

[0031] The signal detection threshold is adaptively adjusted according to the noise floor, and the calculation formula is:

[0032] V th = μ + 3σ

[0033] Wherein, V th is the signal detection threshold, μ is the mean of the background noise, and σ is the variance.

[0034] Preferably, the number of time slots in the slotted ALOHA protocol of the signal processing module is:

[0035] S = 2 N - 1

[0036] In the formula, S is the number of time slots, and N is the conflict signal strength level detected currently.

[0037] Preferably, the real-time processing module includes:

[0038] A dynamic power control unit, according to the path loss model:

[0039] PL(d) = PL0 + 10γlog 10 (d / d0) + X σ

[0040] Wherein, PL(d) is the path loss at a distance d, PL0 is the path loss at a reference distance d0, γ is the path loss exponent, γ = 2.8, d is the actual distance, d0 is the reference distance, and X σ has a mean of 0,

[0041] The frequency agility mechanism executes a frequency hopping sequence when encountering interference:

[0042] f k = f mid + (k × f step ) mod BW

[0043] Wherein, f k is the kth frequency hopping frequency, f min is the minimum frequency, k is the frequency hopping index, k = H(T||ID) mod 256, f step is the frequency step, BW is the bandwidth, and BW = 26 MHz;

[0044] Multi-tag recognition adopts space-time coding technology, and its coding matrix is:

[0045]

[0046] Where s1, s2 are QPSK modulation symbols;

[0047] The processing delay guarantee mechanism is through the formula:

[0048] T total = Tenc +T tx +T proc +T ack

[0049] Among them, T total is the total processing delay, T enc is the encoding delay, T enc ≤50 μs, T tx is the transmission delay, T tx = 256 bit / 40 kbps = 6.4 ms, T proc is the processing delay, T ack is the acknowledgment delay.

[0050] Preferably, the local oscillator frequency configured by the real-time processing module is specifically:

[0051] f n = f0 + n × Δf

[0052] Among them, f n is the local oscillator frequency of the nth channel, f0 is the initial local oscillator frequency, f0 = 902 MHz, Δf is the frequency interval, Δf = 200 kHz, n is the channel number, n ∈ [0, 7].

[0053] Preferably, the formula for establishing a dynamic priority queue is:

[0054]

[0055] Among them, Q is the dynamic priority queue value, w i is the weight coefficient of the ith tag, P i is the signal strength probability value of the ith tag, is the signal strength probability value, α and β are parameters, α = 0.5, β = -60 dBm, e is the natural constant.

[0056] Preferably, it includes a collision detection unit:

[0057] The standing wave ratio detection circuit uses a directional coupler, and the reflection coefficient is:

[0058]

[0059] Among them, Γ is the reflection coefficient, Z L is the load impedance, Z0 is the characteristic impedance;

[0060] Calculate VSWR, and the calculation formula of VSWR is:

[0061]

[0062] In the formula, VSWR is the voltage standing wave ratio;

[0063] The phase detection accuracy reaches 0.1°, and I / Q quadrature demodulation is adopted to calculate the phase difference:

[0064] Δφ = arctan(Q / I)

[0065] where Δφ is the phase difference, Q is the quadrature component, and I is the in-phase component;

[0066] The dynamic range of signal strength detection is 70 dB, the ADC sampling rate is 100 MSPS, and the resolution is 14 bits;

[0067] Interference cancellation uses an LMS adaptive filter, and the update formula is:

[0068] w(n + 1) = w(n) + μe(n)x(n)

[0069] where w(n + 1) is the filter weight of the (n + 1)-th iteration, w(n) is the filter weight of the n-th iteration, μ is the step size, μ = 0.01, e(n) is the error signal of the n-th iteration, and x(n) is the input signal of the n-th iteration.

[0070] Preferably, it is characterized by including an antenna tuning network:

[0071] The adjustable capacitor array is:

[0072]

[0073] where C total is the total capacitance of the adjustable capacitor array, C0 is the initial capacitance, b i is the binary control bit, i = 1, 2, 3, 4, ΔC is the capacitance adjustment step, ΔC = 0.5 pF, and the adjustment accuracy is ±0.25 pF;

[0074] The impedance matching network topology is a π-type structure, and the component values are calculated using the conjugate matching formula

[0075] The tuning response time ≤ 100 μs, and it is adjusted by a PID controller. The proportional coefficient K p = 2.5, and the integral time T i = 50 μs.

[0076] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0077] The anti-collision system of RFID electronic tags proposed by the present invention effectively solves the multi-tag collision problem in high-density and dynamic application scenarios by combining an encryption module, a signal processing module, and a real-time processing module. The encryption module uses a hash function and an elliptic curve encryption algorithm to achieve secure and efficient verification of tag identities, enhancing the security of the system. The signal processing module innovatively combines a hybrid anti-collision mechanism, namely the combination of the slotted ALOHA protocol and the binary tree search algorithm, which can dynamically adjust the number of time slots and search strategies according to actual collision situations, significantly improving the tag recognition efficiency and system throughput. At the same time, the use of MIMO technology and an adaptive signal detection threshold further enhances the accuracy of signal separation and detection. The real-time processing module significantly reduces the processing delay through multi-channel parallel processing and independent local oscillator frequency configuration, ensuring the high-speed response ability of the system. The dynamic power control and frequency agility mechanisms enhance the anti-interference ability and adaptability of the system, enabling it to operate stably in complex electromagnetic environments. The established dynamic priority queue can flexibly schedule the tag response order according to the tag signal strength and service rules, meeting the differentiated requirements of different application scenarios. Description of the Drawings

[0078] Figure 1 It is the system working flowchart of the present invention. Detailed Implementation Modes

[0079] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments in the following description are only examples, and those skilled in the art can think of other obvious variations.

[0080] An RFID electronic tag anti-collision processing system includes: an encryption module, a signal processing module, and a real-time processing module;

[0081] The encryption module is used to authenticate the tag identity based on a hash function;

[0082] The signal processing module adopts a hybrid anti-collision mechanism combining the slotted ALOHA protocol and the binary tree search algorithm;

[0083] The real-time processing module includes a multi-channel parallel processing unit, and each channel is configured with an independent local oscillator frequency;

[0084] The RFID electronic tag anti-collision processing system has significant advantages. The encryption module verifies the tag identity based on a hash function to ensure security; the signal processing module's hybrid anti-collision mechanism improves the recognition efficiency and reduces collisions; the real-time processing module has multi-channel parallel processing and independent local oscillator frequencies, enabling it to process multiple tasks in parallel, enhancing the real-time performance and processing ability of the system, and meeting the requirements of complex scenarios.

[0085] Refer to Figure 1As shown in the figure, the following steps are executed when the system is working:

[0086] S1. The reader broadcasts an encrypted activation signal to synchronize the tags and transmit time slot parameters;

[0087] S2. The tag response signal uses orthogonal frequency division multiplexing technology to split the response data for transmission on subcarriers and returns the encrypted data;

[0088] S3. Dynamically schedule the tag response order according to the signal strength and service rules, and establish a dynamic priority queue;

[0089] S4. Monitor the voltage standing wave ratio (VSWR) in real time through the VSWR monitor. When the VSWR is greater than the preset threshold, trigger the adjustment of the adaptive impedance matching network to optimize the signal transmission quality through impedance matching.

[0090] Broadcast encrypted activation to synchronize and upload parameters to ensure accurate initialization. Use orthogonal frequency division multiplexing to split data transmission to improve efficiency. Dynamically schedule tag responses to establish a priority queue, which is reasonable and orderly. Monitor the VSWR in real time. When the threshold is exceeded, adjust the impedance matching to optimize the signal transmission quality and ensure the stable and reliable operation of the system.

[0091] In the encryption module, we adopt a tag authentication method based on the hash function. This method verifies the identity of the tag by calculating its unique hash value, effectively preventing the access of illegal tags. At the same time, the encryption module also integrates the elliptic curve encryption algorithm to provide high-strength encryption protection for the communication between the reader and the tag. During the tag authentication process, the system executes a three-way handshake protocol to ensure the accuracy of the identities of both parties. The reader first sends a challenge value to the tag. The tag calculates the response value according to the preset key and returns it to the reader. The reader then completes the authentication process by solving the equation for key matching. In addition, the encrypted communication adopts the AES-CTR mode to ensure the security of the data transmission process.

[0092] The signal processing module is the core part of the system of the present invention. It adopts a hybrid anti-collision mechanism combining the slotted ALOHA protocol and the binary tree search algorithm. During the operation of the system, the reader first broadcasts an encrypted activation signal to synchronize the tags and transmit time slot parameters. After receiving the activation signal, the tag uses orthogonal frequency division multiplexing technology to split the response data for transmission on subcarriers and returns the encrypted data to the reader. After receiving the tag response, the reader dynamically schedules the tag response order according to the signal strength and service rules and establishes a dynamic priority queue. The priority value of this queue is calculated based on parameters such as the weight coefficient of the tag and the signal strength probability value, ensuring that high-priority tags can be processed preferentially.

[0093] To achieve more efficient signal processing, the present invention also introduces MIMO technology and an adaptive signal detection threshold mechanism. The MIMO technology improves the reliability and capacity of signal transmission by configuring multiple transmit antennas and multiple receive antennas. The adaptive signal detection threshold mechanism adaptively adjusts the detection threshold according to the noise floor, effectively reducing the bit error rate. In terms of time slot allocation, the system dynamically adjusts the number of time slots according to the intensity level of the detected collision signals to ensure efficient identification of tags.

[0094] The real-time processing module includes a multi-channel parallel processing unit, and each channel is configured with an independent local oscillator frequency. This design enables the system to process the response signals of multiple tags simultaneously, greatly improving the processing speed. In addition, the real-time processing module also integrates a VSWR (Voltage Standing Wave Ratio) monitoring function, which can monitor the VSWR status of the antenna system in real time to ensure the stable operation of the system. When the antenna system is mismatched, the system will automatically adjust the adjustable capacitor array and the impedance matching network to achieve the best matching effect.

[0095] In the aspect of the antenna tuning network, the present invention adopts an adjustable capacitor array and a π-type impedance matching network structure. The adjustable capacitor array adjusts the resonant frequency of the antenna by changing the capacitance value, while the π-type impedance matching network calculates the element values through the conjugate matching formula to achieve impedance matching between the antenna and the reader. The tuning response time is adjusted by a PID controller to ensure the rapid response of the system to changes in the antenna state.

[0096] In summary, an RFID electronic tag anti-collision processing system proposed by the present invention realizes efficient and reliable tag identification by integrating an encryption module, a signal processing module, and a real-time processing module. This system not only solves the multi-tag collision problem in high-density and dynamic application scenarios, but also improves the security, anti-interference ability, and adaptability of the system. In the future, we will continue to optimize and improve this system to meet the requirements of more application scenarios.

[0097] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification is only the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. An RFID electronic tag anti-collision processing system, characterized in that: include: Encryption module, signal processing module and real-time processing module; The encryption module is used to implement tag authentication based on hash functions; The signal processing module adopts a hybrid anti-collision mechanism combining the slotted ALOHA protocol and the binary tree search algorithm; The real-time processing module includes a multi-channel parallel processing unit, and each channel is configured with an independent local oscillator frequency; The system performs the following steps when working: S1, the reader broadcasts the encrypted activation signal E(t) = A·cos(2πf c t+φ(t)), synchronize the tag and transmit the time slot parameters, where E(t) is the encryption activation signal emitted by the reader, A is the signal amplitude, and f c is the carrier frequency, t is the time, φ(t) is the encrypted phase modulation function; S2. The tag response signal uses orthogonal frequency division multiplexing technology to split the response data into subcarriers for transmission and return encrypted data; S3, dynamically schedule the tag response order according to the signal strength and business rules, and establish a dynamic priority queue; S4. Real-time monitoring of the standing wave ratio through VSWR standing wave ratio monitoring. When the VSWR is greater than a preset threshold, the adaptive impedance matching network adjustment is triggered to optimize the signal transmission quality through impedance matching.

2. The RFID electronic tag anti-collision processing system according to claim 1, characterized in that: The encryption module comprises: The key generation unit uses the elliptic curve encryption algorithm, selects the base point G(x,y) on the prime field GF(p), the private key d∈[1,n-1], and the public key Q=d·G, where p=2 256 -2 32 -977; The tag authentication process executes the three-way handshake protocol: The reader sends a challenge value C=H(T1||RND), where C is the challenge value sent by the reader, H is the hash function, T1 is the timestamp, and RND is a 16-byte random number; Tag calculation response value Among them, R is the response value calculated by the tag, H is the hash function, and K T Preset keys for tags; The verification module solves the equation Perform key matching, where K′ T is the key solved by the verification module, R is the response value calculated by the tag, C is the challenge value sent by the reader, and K DB The key is stored in the database, and ID is the unique identification code of the tag; Encrypted communication uses AES-CTR mode, the initial value of the counter CTR = H (T2 || ID) mod 2 128 , each frame of data updates CTR=CTR+1, CTR is the initial value of the counter, T2 is the timestamp, and mod is the modulo operator.

3. The RFID electronic tag anti-collision processing system according to claim 1, characterized in that: The tag identity authentication is implemented based on the hash function, and the hash function expression is: Among them, H is the hash function, ID is the unique identification code of the tag, K is the dynamically generated 128-bit encryption key, T is the timestamp accurate to milliseconds, and SHA256 is the 256-bit version of the secure hash algorithm.

4. The RFID electronic tag anti-collision processing system according to claim 1, characterized in that: The signal processing module comprises: The implementation formula of the time slot allocation algorithm is: t slot =τ×2 L-1 Among them, t slot is the time slot duration, τ is the basic time slot unit, τ = 300 μs is the basic time slot unit, L is the conflict level, L∈[1,5] is the conflict level; Binary search process execution: When k label conflicts are detected, the query prefix is ​​split into P0||b, b∈{0,1}, and the recursive depth D satisfies 2 D ≥k; Signal separation uses MIMO technology and is configured with N t = 4 transmitting antennas, N r = 2 receiving antennas, channel matrix The precoding matrix W = H is calculated by the zero-forcing algorithm H (HH H ) -1 ; The signal detection threshold is adaptively adjusted according to the noise floor, and the calculation formula is: V th =μ+3σ Among them, V th is the signal detection threshold, μ is the background noise mean, and σ is the variance.

5. The RFID electronic tag anti-collision processing system according to claim 1, characterized in that: The number of time slots in the Slotted ALOHA protocol of the signal processing module is: S＝2 N -1 Where S is the number of time slots and N is the currently detected conflict signal strength level.

6. The RFID electronic tag anti-collision processing system according to claim 1, characterized in that: The real-time processing module comprises: Dynamic power control unit, based on the path loss model: PL(d)=PL0+10γlog 10 (d / d0)+X σ Where PL(d) is the path loss at distance d, PL0 is the path loss at reference distance d0, γ is the path loss exponent, γ = 2.8, d is the actual distance, d0 is the reference distance, X σ The mean is 0, The frequency agility mechanism performs a frequency hopping sequence when encountering interference: f k =f min +(k×f step )mod BW Among them, f k is the kth frequency hopping frequency, f min is the minimum frequency, k is the frequency hopping index, k = H(T||ID) mod 256, f step is the frequency step, BW is the bandwidth, BW=26MHz; Multi-label recognition uses space-time coding technology, and its coding matrix is: Where s1, s2 are QPSK modulation symbols; The processing delay guarantee mechanism is implemented through the formula: T total =T enc +T tx +T proc +T ack Among them, T total is the total processing delay, T enc is the coding delay, T enc ≤50μs, T tx is the transmission delay, T tx =256bit / 40kbps=6.4ms, T proc To process the delay, T ack Delay in confirming.

7. The RFID electronic tag anti-collision processing system according to claim 1, characterized in that: The real-time processing module is configured with an independent local oscillator frequency specifically as follows: f n =f0+n×Δf Among them, f n is the local oscillator frequency of the nth channel, f0 is the initial local oscillator frequency, f0 = 902 MHz, Δf is the frequency interval, Δf = 200 kHz, n is the channel number, n∈[0,7].

8. The RFID electronic tag anti-collision processing system according to claim 1, characterized in that: The formula for establishing a dynamic priority queue is: Among them, Q is the dynamic priority queue value, w i is the weight coefficient of the i-th label, P i is the signal strength probability value of the i-th tag, is the signal strength probability value, α and β are parameters, α=0.5, β=-60dBm, and e is a natural constant.

9. The RFID electronic tag anti-collision processing system according to claim 1, characterized in that: Contains conflict detection unit: The standing wave ratio detection circuit uses a directional coupler, and the reflection coefficient is: Where Γ is the reflection coefficient, Z L is the load impedance, Z0 is the characteristic impedance; Calculate VSWR, where the calculation formula for VSWR is: Where VSWR is the voltage standing wave ratio; The phase detection accuracy reaches 0.1°, and I / Q quadrature demodulation is used to calculate the phase difference: Δφ=arctan(Q / I) Among them, Δφ is the phase difference, Q is the orthogonal component, and I is the in-phase component; Signal strength detection dynamic range 70dB, ADC sampling rate 100MSPS, resolution 14bit; Interference elimination uses LMS adaptive filter, and the update formula is: w(n+1)=w(n)+μe(n)x(n) Wherein, w(n+1) is the filter weight of the n+1th iteration, w(n) is the filter weight of the nth iteration, μ is the step size, μ=0.01, e(n) is the error signal of the nth iteration, and x(n) is the input signal of the nth iteration.

10. The RFID electronic tag anti-collision processing system according to claim 1, characterized in that Contains antenna tuning network: The adjustable capacitor array is: Among them, C total is the total capacitance of the adjustable capacitor array, C0 is the initial capacitance, b i is the binary control bit, i=1,2,3,4, ΔC is the capacitance adjustment step, ΔC=0.5pF, and the adjustment accuracy is ±0.25pF; The impedance matching network topology is a π-type structure, and the component value calculation uses the conjugate matching formula Tuning response time ≤ 100μs, adjusted by PID controller, proportional coefficient K p =2.5, integration time T i =50μs.

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