A method of detecting the approach of a radio frequency circuit to a steady state

Abstract

This invention relates to a method for detecting whether a radio frequency (RF) circuit is close to steady state, belonging to the field of integrated circuit computer-aided design technology. This invention can automatically detect whether an RF circuit is close to steady state. First, it can ensure that the circuit state is close to steady state at the end of the transient analysis time, which provides a better initial value for subsequent Newton iterations and helps the iteration converge better. Second, when the circuit is detected to be close to steady state, the transient analysis can be stopped immediately and Newton iteration can be started, avoiding excessively long transient analysis and reducing simulation time consumption.

Description

Technical Field

[0001] This invention belongs to the field of computer-aided design technology for integrated circuits. Specifically, this invention relates to a method for detecting when a radio frequency circuit is close to a steady state. Background Technology

[0002] Radio frequency (RF) circuits are a special type of analog circuit widely used in wireless signal transmission and communication, such as Bluetooth, WiFi, radar, and navigation. RF circuits operate at higher frequencies than ordinary analog circuits, and their design specifications are calculated based on the steady-state periodicity of the circuit after it reaches a steady state. Therefore, the primary task of RF simulation is to find the steady state of the circuit, that is, to find the periodic waveforms of all circuit signals.

[0003] like Figure 1 As shown, radio frequency circuits generally operate at high frequencies, and the time to reach steady-state operation is difficult to predict, usually requiring tens of thousands or even millions of cycles. If transient analysis using a general-purpose SPICE simulator is used to find the circuit's steady state, the simulation time can reach several weeks or even months, which is unacceptable for circuit design.

[0004] Shooting Newton's method and harmonic balance are commonly used methods for calculating the steady state of RF circuits. Both methods are essentially Newton iterations, treating the steady state as an unknown and avoiding lengthy transient simulations. Newton iteration is a locally convergent algorithm, and its convergence is greatly affected by the initial value. If zero voltage is used as the initial value, the iteration process will encounter significant convergence difficulties due to the initial value being too far from the true solution and the circuit's nonlinearity. To improve convergence, a short transient analysis is usually performed on the circuit before entering the steady-state solution iteration. Then, the voltage value of the last cycle of the transient analysis is used as the initial value to begin the impulse Newton or harmonic balance iteration. This process of selecting the initial value through transient analysis is called the steady-state process (stab), and the duration of the transient analysis is called tstab. Figure 1 As shown, when 200ns is selected as tstab, the transient waveform is closer to the steady state. Using it as the initial value to start the iteration will definitely result in better convergence than the transient waveform with tstab of 20ns.

[0005] Because RF circuits are diverse in type, function, and specifications, it is impossible to select a fixed tstab length for transient analysis to determine the initial value for iteration. If the tstab length is too short, the circuit's operating state is still far from steady state, and using it as an initial value may cause convergence problems. If the tstab length is too long, it can ensure that the circuit state is close to steady state, but an excessively long tstab does not significantly improve iteration convergence while consuming additional time for transient analysis. Therefore, a method is needed to detect whether the circuit is close to steady state. Summary of the Invention

[0006] To address the aforementioned issues, this invention proposes a method for detecting radio frequency circuits approaching steady state. When detecting near-steady state, the transient analysis of the steady-state phase is automatically stopped, and Newton iteration is initiated instead. This improves the iteration convergence performance and avoids the additional simulation workload caused by excessively long transient analysis, thereby improving simulation efficiency.

[0007] A first aspect of the present invention provides a method for detecting that a radio frequency circuit is approaching a steady state, comprising:

[0008] Step S1: Obtain the circuit period T based on the circuit excitation frequency and initialize the parameters;

[0009] In step S2, if the number of times n>10, then proceed to step S10; otherwise, proceed to step S3.

[0010] Step S3: Perform transient simulation of length [(n-1)MT, nMT];

[0011] Step S4: Extract the voltage data V(t) of the kth circuit node;

[0012] Step S5: Based on the voltage data V(t) of the kth circuit node, calculate the amplitude a1 and average value d1 in the interval [nMT-2T, nMT-T], and the amplitude a2 and average value d2 in the interval [nMT-T, nMT].

[0013] Step S6: Determine whether the first qualification condition is met. If yes, set f1 = false. Determine whether the second qualification condition is met. If yes, set f2 = false.

[0014] Step S7: Determine whether all circuit nodes have been traversed. If not, let k = k + 1 and execute step S4. If all circuit nodes have been traversed, execute step S8.

[0015] Step S8: Determine whether the steady-state condition has been reached. If yes, retain the result state of [nMT-T, nMT] and execute S10. If no, execute step S9.

[0016] Step S9: Set n = n + 1, k = 1, then proceed to step S2.

[0017] Step S10: Terminate, obtain the waveform of [nMT-T, nMT] as the initial value for iteration;

[0018] The parameter initialization includes setting the following initial values: number of times n = 1, node counter k = 1, number of periods M, number of nodes K, Boolean variables f1 = true, f2 = true, amplitude determination threshold P and average value determination threshold Q.

[0019] Furthermore, in step S3, performing a transient simulation of length [(n-1)MT, nMT] involves calling the general SPICE simulation software to perform a transient simulation on the current circuit.

[0020] Furthermore, in step S5:

[0021]

[0022]

[0023] Where t is time.

[0024] Furthermore, in step S6:

[0025] The first condition for meeting the standard is |a1-a2|>P. If the result is yes, then let f1 = false; if it is no, then f1 = true.

[0026] The second condition for meeting the standard is |d1-d2|>Q. If the result is yes, then let f2=false; if it is no, then f2=true.

[0027] Furthermore, in step S7, determining whether all circuit nodes have been traversed specifically includes: when k = K, determining that all circuit nodes have been traversed.

[0028] Furthermore, in step S8, the steady-state condition is: f1 = true and f2 = true; if the steady-state condition is true, then a steady state is reached.

[0029] A second aspect of the present invention provides an electronic device comprising:

[0030] At least one processor; and a memory communicatively connected to said at least one processor; wherein,

[0031] The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform a method for detecting radio frequency circuits approaching steady state as described in the first aspect of the invention.

[0032] A third aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, the computer program being loadable by a processor and executable as described in the first aspect of the present invention, a method for detecting radio frequency circuits approaching steady state.

[0033] The advantages of this invention compared to the prior art are:

[0034] This invention can automatically detect whether an RF circuit is close to steady state. First, it can ensure that the circuit is close to steady state at the end of the transient analysis time length tstab, which provides a good initial value for the subsequent Newton iteration and helps the iteration converge better. Second, it can immediately stop the transient analysis and enter the Newton iteration when the circuit is detected to be close to steady state, avoiding excessively long transient analysis and reducing the simulation time consumption. Attached Figure Description

[0035] Figure 1 This is a schematic diagram showing the time it takes for the operating frequency of a current-technical radio frequency circuit to reach steady-state operation.

[0036] Figure 2 This is a flowchart of a method for detecting radio frequency circuits approaching steady state, provided by an embodiment of the present invention.

[0037] Figure 3 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0038] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0039] Method Implementation Examples

[0040] The purpose of this invention is to provide a method for detecting the near-steady-state state of a radio frequency (RF) circuit, thereby avoiding inaccurate simulation results or low simulation efficiency that may result from manually setting the maximum harmonic number, and improving the usability of simulation software. To solve the above problems, a first aspect of this invention provides a method based on detecting the near-steady-state state of an RF circuit, such as... Figure 2 As shown.

[0041] A method based on detecting radio frequency circuits approaching steady state includes:

[0042] S1: Obtain the circuit period T based on the circuit excitation frequency and initialize the parameters.

[0043] The parameter initialization includes setting the number of cycles n=1, the node counter k=1, the number of cycles M, the number of nodes K, the Boolean variables f1=true, f2=true, and the amplitude judgment threshold P and the average value judgment threshold Q to initial values.

[0044] SPICE simulation software is a circuit simulation software. Parameter initialization refers to initializing the parameters of a general-purpose SPICE simulation software.

[0045] Preferably, the number of periods M is 100, and the initial values ​​of the amplitude determination threshold P and the average value determination threshold Q are between 1e-2 and 1e-3.

[0046] S2, if the number of times n>10, then go to step S10, otherwise go to step S3.

[0047] S3, perform transient simulation of length [(n-1)MT, nMT].

[0048] In this step, the transient simulation of length [(n-1)MT, nMT] is performed by calling the general SPICE simulation software to perform transient simulation on the current circuit.

[0049] This embodiment uses fixed time intervals to perform transient simulations, and determines the steady state after each interval's transient simulation is completed.

[0050] Transient simulation is a common function of SPICE simulation software. Through transient simulation, the waveforms of voltage changes at each node in the circuit with respect to time can be obtained, i.e., voltage data V(t).

[0051] S4, extract the voltage data V(t) of the kth circuit node.

[0052] S5. Based on the voltage data V(t) of the kth circuit node, calculate the amplitude a1 and average value d1 in the interval [nMT-2T, nMT-T], and the amplitude a2 and average value d2 in the interval [nMT-T, nMT].

[0053] in,

[0054]

[0055] Where t is time.

[0056] S6. Determine whether the first condition for meeting the standard is met. If yes, set f1 = false. Determine whether the second condition for meeting the standard is met. If yes, set f2 = false.

[0057] In this step, the first condition for achieving the target is |a1-a2|>P. If it is true, then let f1 = false; if it is false, then let f1 = true.

[0058] The second condition for meeting the standard is |d1-d2|>Q. If it is true, then let f2 = false; if it is false, then f2 = true.

[0059] S7. Determine whether all circuit nodes have been traversed. If not, let k = k + 1 and execute step S4. If all circuit nodes have been traversed, execute step S8.

[0060] Specifically, determining whether all circuit nodes have been traversed includes: when k = K, determining that all circuit nodes have been traversed.

[0061] S8. Determine whether the steady-state condition has been reached. If yes, retain the result state of [nMT-T, nMT] and execute S10. If no, execute step S9.

[0062] The steady-state conditions are: f1 = true and f2 = true. If the steady-state conditions are met, then steady state is reached.

[0063] S9, set n = n + 1, k = 1, then proceed to step S2.

[0064] S10, terminate, obtain the waveform of [nMT-T, nMT] as the initial value for iteration.

[0065] This invention performs transient simulations in segments with fixed durations, and determines the steady state after each segment's transient simulation is completed. This solves the technical challenge of determining the initial values ​​for iterations by selecting a fixed tstab length due to the diverse types, functions, and specifications of RF circuits. After completing the transient analysis of each segment, this invention calculates the amplitudes a1, a2 and average values ​​d1, d2 of each node in the last two cycles as indicators for determining the steady state. This solves the convergence problem caused by the difficulty in choosing the tstab duration, saves analysis time, and improves design efficiency.

[0066] by Figure 1 Taking the signal as an example, the implementation of the present invention will be described.

[0067] Assuming the circuit excitation frequency is 500MHz, the period T is 2ns. Set the number of periods M = 100, P = 1e-9, and Q = 1e-6.

[0068] The first step is to perform transient analysis in the range [0, 200 ns] to calculate the voltage data V(t) of the first circuit node.

[0069] The amplitudes and average values at [196ns, 198ns] and [198ns, 200ns] are obtained as a1 = 1.96V, a2 = 1.98V, d1 = 1.2e-5V, and d2 = 1.3e-5V respectively. It can be determined that |a1 - a2| > P and |d1 - d2| > Q. Therefore, the circuit has not reached a near-steady state at this time.

[0070] Perform a transient analysis again on [200ns, 400ns] to calculate the voltage data V(t) of the second circuit node at

[0071] The amplitudes and average values at [396ns, 398ns] and [398ns, 400ns] are obtained as a1 = 1.99V, a2 = 1.99V, d1 = 1.2e-6V, and d2 = 1.3e-6V respectively.

[0072] Judge the threshold again. Since |a1 - a2| < P and |d1 - d2| < Q, the circuit meets the standard of being near the steady state, and save

[0073] the waveform at [398ns, 400ns] as the initial value of the iteration, and terminate.

[0074] Embodiment of the electronic device

[0075] In a second aspect of the present invention, an electronic device is provided, including:

[0076] at least one processor; and a memory communicatively connected to the at least one processor; wherein,

[0077] the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute a method for detecting that a radio frequency circuit is near a steady state according to the first aspect of the present invention.

[0078] Figure 3 is a schematic structural diagram of an electronic device according to an embodiment of the present invention. As Figure 3 shown, the electronic device may include one or more ( Figure 3 only one is shown in ) processors 102 (the processor 102 may include but is not limited to a microprocessor (abbreviated as MPU) or a programmable logic device (abbreviated as PLD)) and a memory 104 for storing data. In an exemplary embodiment, the above-mentioned electronic device may further include a transmission device 106 for communication functions and an input / output device 108. Those of ordinary skill in the art can understand that Figure 3The structure shown is for illustrative purposes only and does not limit the structure of the terminal device described above. For example, the terminal device may also include components that are more... Figure 3 The more or fewer components shown, or having the same Figure 3 Equivalent functions or ratios shown Figure 3 The functions shown have more different configurations.

[0079] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the method in this embodiment of the invention. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, thereby implementing the above-described method. The memory 104 may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to terminal devices via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0080] The transmission device 106 is used to receive or send data via a network. Specific examples of the network described above may include a wireless network provided by the communication provider of the switching device. In one example, the transmission device 106 includes a Network Interface Controller (NIC), which can connect to other network devices via a base station to communicate with the Internet. In another example, the transmission device 106 may be a Radio Frequency (RF) module used for wireless communication with the Internet.

[0081] Computer-readable storage medium embodiments

[0082] A third aspect of the invention provides a computer-readable storage medium having a computer program stored thereon, the computer program being loadable and executed by a processor for a method for detecting radio frequency circuits approaching steady state as described in the first aspect.

[0083] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A method for detecting radio frequency circuits approaching steady state, characterized in that, include: Step S1: Obtain the circuit period T based on the circuit excitation frequency and initialize the parameters; Step S2: If the number of times n>10, then execute step S10; otherwise, execute step S3. Step S3: Perform transient simulation of length [(n-1)MT, nMT]; Step S4: Extract the voltage data V(t) of the kth circuit node; Step S5: Based on the voltage data V(t) of the kth circuit node, calculate the amplitude a1 and average value d1 in the interval [nMT-2T, nMT-T], and the amplitude a2 and average value d2 in the interval [nMT-T, nMT]. Step S6: Determine if the first qualification condition is met. If yes, set f1 = false; determine if the second qualification condition is met. If yes, set f2 = false, where: The first condition for achieving the target is |a1-a2|>P. If the result is yes, then let f1=false; if it is no, then f1=true. The second condition for meeting the standard is |d1-d2|>Q. If the result is yes, then let f2=false; if it is no, then f2=true. Step S7: Determine whether all circuit nodes have been traversed. If not, let k = k + 1 and execute step S4. If all circuit nodes have been traversed, execute step S8. Step S8: Determine whether the steady-state condition has been reached. If yes, retain the result state of [nMT-T, nMT] and execute S10. If no, execute step S9. Step S9: Set n=n+1, k=1, then proceed to step S2. Step S10: Terminate, obtain the waveform of [nMT-T, nMT] as the initial value for iteration; The parameter initialization includes setting the following initial values: number of cycles n=1, node counter k=1, number of cycles M, number of nodes K, Boolean variables f1=true, f2=true, amplitude determination threshold P and average value determination threshold Q.

2. The method for detecting radio frequency circuits approaching steady state according to claim 1, characterized in that: In step S3, performing a transient simulation of length [(n-1)MT, nMT] involves calling the general SPICE simulation software to perform a transient simulation on the current circuit.

3. The method for detecting radio frequency circuits approaching steady state according to claim 2, characterized in that, In step S5: ， ， ， ， Where t is time.

4. The method for detecting radio frequency circuits approaching steady state according to claim 1, characterized in that, In step S7, determining whether all circuit nodes have been traversed specifically includes: when k=K, determining that all circuit nodes have been traversed.

5. The method for detecting radio frequency circuits approaching steady state according to claim 4, characterized in that, In step S8, the steady-state condition is: f1=true and f2=true; if the steady-state condition is true, then steady state is reached.

6. An electronic device, characterized in that, include: At least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores instructions executable by the at least one processor, which, when executed by the at least one processor, enables the at least one processor to perform a method for detecting a radio frequency circuit approaching a steady state as described in any one of claims 1 to 5.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium has a computer program stored thereon, which can be loaded and executed by a processor as described in any one of claims 1 to 5, a method for detecting radio frequency circuits approaching steady state.

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