Ultra-wideband circulator based on periodic modulation topology circuit

Abstract

The invention discloses an ultra-wideband circulator based on a periodic modulation topology circuit, and belongs to the technical field of microwave and radio frequency nonreciprocal circuits. The working bandwidth range of the circulator is widened, and non-reciprocal transmission is achieved through non-magnetic materials. A time sequence control unit is respectively connected with a Floquet topology circuit layer, a clock signal driving module, a reset signal driving module and a start signal driving module; the Floquet topology circuit layer is respectively connected with a first coupling port, a second coupling port and a third coupling port; the other ends of the first coupling port, the second coupling port, the third coupling port, the clock signal driving module, the reset signal driving module and the starting signal driving module are respectively grounded; the Floquet topology circuit layer adopts a six-layer parallel network structure, and each layer of network structure comprises a coupling capacitor and three N-type MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) switches. The advantages of the switched capacitor structure are utilized, and the signal processing capacity which is high in integration level, small in size and capable of breaking through delay-bandwidth limitation is achieved.

Description

Technical Field

[0001] This invention belongs to the field of microwave and radio frequency non-reciprocal circuit technology, and specifically relates to an ultrawideband circulator based on a periodic modulation topology circuit. Background Technology

[0002] Circulators are core components in microwave communication, radar, and sensor systems, used to achieve non-reciprocal signal transmission, meaning that a signal input from a designated port is only output from a specific port, avoiding signal crosstalk. Traditional circulators rely on magnetic materials such as ferrites, using an external magnetic field to achieve non-reciprocity. However, magnetic materials are incompatible with semiconductor manufacturing processes, resulting in large device size, high cost, difficulty in integration, and limited bandwidth. Existing non-magnetic non-reciprocal technologies mainly include active transistor biasing, nonlinear material modulation, and time-limited modulation. Among these, active transistor solutions suffer from high noise and poor linearity; nonlinear material modulation results in narrow non-reciprocal transmission bandwidth and severe signal distortion; traditional time-limited modulation circulators face a trade-off between modulation speed, device size, and bandwidth, making it difficult to simultaneously achieve ultra-wideband, miniaturization, and high integration, thus limiting their application in modern ultra-wideband communication and integrated systems.

[0003] Topological insulators (TIs), a significant discovery in condensed matter physics, are characterized by their bulk insulation and boundary state conductivity. Furthermore, the boundary states exhibit unidirectional transport and robustness against backscattering, properties stemming from the topological protection mechanism of the quantum Hall effect. In electromagnetic systems, the realization of topological insulators offers new insights for designing high-performance microwave devices, such as non-reciprocal transport, low-loss waveguides, and interference-resistant communication systems. In recent years, Floquet topological insulators have been proposed for achieving non-reciprocal transport without a magnetic field. By periodically driving the Hamiltonian to achieve topological order, they theoretically break the limitations of static systems. Extending this principle to circuit systems, Floquet topological circuits—as a dynamic modulation system—leverage a core mechanism that breaks the system's time-reversal symmetry without an external magnetic field through periodic time modulation. Summary of the Invention

[0004] This invention aims to address the problems of narrow operating bandwidth and difficulty in achieving transmission without magnetic materials in existing circulators. To this end, an ultra-wideband circulator based on a periodic modulation topology circuit is proposed.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] An ultrawideband circulator based on a periodic modulation topology includes a timing control unit, a Floquet topology layer, a first coupling port, a second coupling port, a third coupling port, a clock signal driving module, a reset signal driving module, and a start signal driving module.

[0007] The timing control unit is connected to the Floquet topology circuit layer, the clock signal driving module, the reset signal driving module and the start signal driving module respectively. The Floquet topology circuit layer is connected to the first coupling port, the second coupling port and the third coupling port respectively.

[0008] The other ends of the first coupling port, the second coupling port, the third coupling port, the clock signal driving module, the reset signal driving module, and the start signal driving module are respectively grounded;

[0009] The Floquet topology circuit layer adopts a six-layer parallel network structure. Each layer includes a coupling capacitor and three N-type MOSFET transistor switches. The first coupling port is connected to the first N-type MOSFET transistor switch in each layer, the second coupling port is connected to the second N-type MOSFET transistor switch in each layer, and the third coupling port is connected to the third N-type MOSFET transistor switch in each layer. The other ends of the three N-type MOSFET transistor switches in each layer are respectively connected to the coupling capacitor of the same layer, and the coupling capacitor is grounded.

[0010] Furthermore, the first coupling port consists of a resistor and an input pulse source, the second coupling port consists of a resistor, and the third coupling port consists of a resistor.

[0011] Furthermore, after receiving the clock drive signal, reset drive signal, and start drive signal from the clock signal drive module, reset signal drive module, and start signal drive module, the timing control unit generates six periodic pulse signals for periodic modulation of the Floquet topology circuit layer.

[0012] Furthermore, the timing control unit generates six timing periodic pulse signals with a frequency of 500MHz. The six timing periodic pulse signals are cyclically turned on at an interval of 0.25ns to interleave and control the switching on and off of transistors in the Floquet topology circuit layer (2).

[0013] Furthermore, the timing control unit generates a time-domain modulation function for the periodic pulse signal of the nth timing path. Represented as:

[0014]

[0015] Among them, Tmod For the modulation period, T slot The conduction time of a single time slot; This is a rectangular pulse function representing the switching state of the MOSFET; Let k be the delay time of the nth signal, k be the period number, and t be the time.

[0016] Determined by the phase relationship, the expression is:

[0017]

[0018] in, Represents the phase of the nth signal. Represents the initial phase.

[0019] Furthermore, if the Floquet topology layer is equivalent to a time-varying conductance network, according to Kirchhoff's laws, the first... Layer and First Instantaneous current between layers The calculation formula is:

[0020]

[0021] in, It is at time t, the first Layer and First Time-varying conductance V controlled by transistor switching between layers i (t) represents the th time at time t. Layer voltage, V j (t) represents the th time at time t. The voltage of the layer.

[0022] Furthermore, the aforementioned ultrawideband circulator based on a periodic modulation topology is based on the quasi-electrostatic wave principle, and the signal energy storage density w E Dominated by electric field energy, the expression is:

[0023]

[0024] Where C is the value of the coupling capacitor and V is the voltage across the coupling capacitor.

[0025] Furthermore, the group velocity of the ultrawideband circulator based on a periodic modulation topology circuit... Determined by the modulation frequency, the expression is:

[0026]

[0027] in, The modulation frequency.

[0028] The beneficial effects of this invention are:

[0029] The ultrawideband circulator based on a periodically modulated topology circuit described in this invention mainly consists of three parts: a timing control unit, a Floquet topology circuit layer, and coupling ports. This enables timing-based control and non-reciprocal characteristic analysis of the topology circuit. The clock (V...) clk ), reset (V rst ) and Startup (V start The driving signals are used to complete the timing drive and synchronization of the entire system. After receiving the driving signals, the timing control unit generates six precisely timed periodic pulse signals to periodically modulate the topology layer. These six modulated signals drive the switch array with a specific phase difference and are the core control signals for realizing the non-reciprocal circulator function of the three physical ports. The coupling ports (e.g., including resistors R1, R2, R3 for impedance matching and a pulse source V for feeding external RF excitation signals into the Floquet topology layer) are also included. pluse After receiving the modulated signal, the Floquet topology layer synthesizes the helical motion of electromagnetic waves by periodically charging and discharging the capacitors in its internal Layer 1 to Layer 6 multilayer structure. This system achieves non-reciprocal transmission characteristics: a signal input at port 1 is output from port 2, an input at port 2 is output from port 3, and an input at port 3 is output from port 1. This invention utilizes the advantages of switched-capacitor structures to achieve signal processing capabilities with high integration, miniaturization, and breakthrough of delay-bandwidth limitations.

[0030] The present invention discloses an ultrawideband circulator based on a periodic modulation topology circuit. By introducing a Floquet topology circuit layer and a time modulation mechanism, the present invention achieves wideband non-reciprocal transmission in the 50MHz–1.8GHz frequency band, which is significantly better than traditional ferrite circulators that typically only support relatively narrowband transmission.

[0031] This invention discloses an ultra-wideband circulator based on a periodic modulation topology circuit. Utilizing a timing control unit controlled by a periodic pulse source, the system can adjust its operating frequency and transmission direction according to different application requirements, providing high programmability and flexibility. This invention employs a planar structural design, solving the problems of large size and difficulty in integration of traditional ferrite circulators, making it suitable for the miniaturization and integration needs of modern communication systems.

[0032] The ultrawideband circulator based on a periodic modulation topology described in this invention exhibits high stability and strong anti-interference capability. The design of the Floquet topology layer improves the system's robustness to manufacturing errors and environmental changes, ensuring stable operation of the device in complex environments. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of an ultrawideband circulator based on a periodic modulation topology circuit according to the present invention.

[0034] Figure 2 This is a schematic diagram of the Floquet topology circuit layer described in this invention;

[0035] Figure 3 This is a test diagram of the coupling port transmission characteristics of the present invention;

[0036] Figure 4 This is a timing diagram of the voltage of the coupling capacitor network of the present invention;

[0037] Figure 5 This is a timing diagram of the modulation signal of the present invention;

[0038] Figure 6 This is a diagram of the scattering parameters of the present invention. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described specific embodiments are merely a part of the embodiments of the invention, and not all of them. The components of the specific embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations, and the invention may also have other embodiments.

[0040] Therefore, the following detailed description of specific embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected specific embodiments of the invention. All other specific embodiments obtained by those skilled in the art based on these specific embodiments without inventive effort are within the scope of protection of this invention.

[0041] To further understand the invention's content, features, and effects, the following specific embodiments are provided, along with accompanying drawings. Figure 1 -Appendix Figure 6 Detailed explanation is as follows:

[0042] Example 1:

[0043] An ultrawideband circulator based on a periodic modulation topology includes a timing control unit 1, a Floquet topology layer 2, a first coupling port 3, a second coupling port 4, and a third coupling port 5.

[0044] Clock signal drive module 6, reset signal drive module 7, and start signal drive module 8;

[0045] The timing control unit 1 is connected to the Floquet topology circuit layer 2, the clock signal driving module 6, the reset signal driving module 7, and the start signal driving module 8, respectively. The Floquet topology circuit layer 2 is connected to the first coupling port 3, the second coupling port 4, and the third coupling port 5, respectively.

[0046] The other ends of the first coupling port 3, the second coupling port 4, the third coupling port 5, the clock signal driving module 6, the reset signal driving module 7, and the start signal driving module 8 are respectively grounded;

[0047] The Floquet topology circuit layer 2 adopts a six-layer parallel network structure. Each layer includes a coupling capacitor and three N-type MOSFET transistor switches. The first coupling port 3 is connected to the first N-type MOSFET transistor switch in each layer, the second coupling port 4 is connected to the second N-type MOSFET transistor switch in each layer, and the third coupling port 5 is connected to the third N-type MOSFET transistor switch in each layer. The other ends of the three N-type MOSFET transistor switches in each layer are respectively connected to the coupling capacitor of the same layer, and the coupling capacitor is grounded.

[0048] Furthermore, the first coupling port 3 consists of a resistor and an input pulse source, the second coupling port 4 consists of a resistor, and the third coupling port 5 consists of a resistor.

[0049] Furthermore, after receiving the clock drive signal, reset drive signal, and start drive signal from the clock signal drive module 6, the reset signal drive module 7, and the start signal drive module 8, the timing control unit 1 generates six periodic pulse signals for periodic modulation of the Floquet topology layer 2.

[0050] Furthermore, the timing control unit 1 generates six timing periodic pulse signals with a frequency of 500MHz. The six timing periodic pulse signals are cyclically turned on at an interval of 0.25ns to interleave and control the switching on and off of transistor switches in the Floquet topology circuit layer (2).

[0051] Furthermore, the Floquet topology circuit layer is connected to the coupling port via pins P1, P2, and P3, and to the timing control unit via pins ctrl1<1:6>, ctrl2<1:6>, and ctrl3<1:6>, respectively. The electrical energy stored in the capacitor is transmitted directionally through the periodic switching of the switch array. During signal transmission, the electrical energy is mainly stored in the form of an electric field, avoiding frequent conversion of magnetoelectric energy and overcoming the delay-bandwidth limitation.

[0052] Furthermore, by utilizing a time-controlled switched-capacitor network to simulate the helical motion of charges in a magnetic field, an equivalent synthetic magnetic field is introduced into the circuit, enabling electromagnetic waves to propagate unidirectionally only along specific topological edge states, thus achieving non-reciprocity. In addition, the energy in the system is primarily stored in capacitors as electrical energy, and signal transmission is driven by active switching timing rather than determined by the passive resonance of traditional dielectrics. Therefore, this architecture effectively decouples the dependence of signal transmission speed on physical size, thereby overcoming the inherent delay-bandwidth product limitation in traditional passive devices. The circulator mainly consists of a timing control unit, a Floquet topology circuit layer, and coupling ports 1, 2, and 3. The Floquet topology circuit layer uses N-type MOSFET transistors to form a switching array, and achieves non-reciprocal propagation of electromagnetic waves through coupling capacitors and ports. The timing control unit consists of a periodic pulse source, whose output modulated signal with a period of 2ns and a conduction interval of 0.25ns drives the gate of the N-type MOSFET transistors, precisely controlling the charging and discharging timing of the coupling capacitors. Through the aforementioned structure and timing control, a non-reciprocal transmission characteristic is achieved: when the signal is input at port 1, it is output at port 2; when input at port 2, it is output at port 3; and when input at port 3, it is output at port 1. The modulated signal is transmitted to the Floquet topology layer via integrated traces, implementing periodic control of the switch array to achieve cyclic conduction of the switch and capacitor pairs. This timing control mechanism simulates the helical rotation of electromagnetic waves in a two-dimensional plane, imparting a non-reciprocal angular momentum bias to the topology layer, thereby breaking the time-reversal symmetry of the system and ultimately achieving unidirectional signal transmission.

[0053] Furthermore, the timing control unit 1 generates a time-domain modulation function for the periodic pulse signal of the nth timing sequence. Represented as:

[0054]

[0055] Among them, T mod For the modulation period, T slot The conduction time of a single time slot; This is a rectangular pulse function representing the switching state of the MOSFET; Let k be the delay time of the nth signal, k be the period number, and t be the time.

[0056] Determined by the phase relationship, the expression is:

[0057]

[0058] in, Represents the phase of the nth signal. Represents the initial phase.

[0059] Furthermore, if we consider the Floquet topology layer 2 as an equivalent time-varying conductance network, according to Kirchhoff's laws, the... Layer and First Instantaneous current between layers The calculation formula is:

[0060]

[0061] in, It is at time t, the first Layer and First Time-varying conductance V controlled by transistor switching between layers i (t) represents the th time at time t. Layer voltage, V j (t) represents the th time at time t. The voltage of the layer.

[0062] Furthermore, the aforementioned ultrawideband circulator based on a periodic modulation topology is based on the quasi-electrostatic wave principle, and the signal energy storage density w E Dominated by electric field energy, the expression is:

[0063]

[0064] Where C is the value of the coupling capacitor and V is the voltage across the coupling capacitor.

[0065] Furthermore, the group velocity of the ultrawideband circulator based on a periodic modulation topology circuit... Determined by the modulation frequency, the expression is:

[0066]

[0067] in, The modulation frequency.

[0068] Furthermore, because the switch array is turned on sequentially in a specific direction, this time-varying conductance generates an equivalent composite gauge field. In the frequency domain, this time-modulation effect causes different phase factors to accumulate as forward propagation (along the switch-on sequence) and reverse propagation (against the switch-on sequence) pass through the network. For signal frequency Its equivalent non-reciprocal transmission property satisfies:

[0069]

[0070] This characteristic stems from the spacetime evolution operator of the system's Hamiltonian. The eigenstates possess non-trivial topological invariants. When the signal frequency is within the topological bandgap, the circuit supports unidirectional propagation of edge states.

[0071] In this embodiment, the non-reciprocal performance of the circulator is verified by simulation. During the simulation, a circuit model is built, in which the N-type MOSFET transistor adopts a device model using 55nm CMOS technology, and the six pulse signals generated by the timing control unit have a period of 2ns and a phase interval of 0.25ns.

[0072] from Figure 3 The simulation results show that when an excitation signal is input from Port1, Port2 has a significant voltage output, while the output voltage of Port3 is close to 0, which directly verifies the non-reciprocal transfer characteristic between Port1 and Port2. Similarly, when an excitation signal is input to Port2, the signal is only output from Port3. When an excitation signal is input to Port3, the signal is only output from Port1, which meets the non-reciprocal transfer requirement of the circulator.

[0073] Figure 4 Simulation results demonstrate the Floquet topology layer arrive The voltage timing shows that the voltage changes of each capacitor are periodic and have phase differences. This result verifies that under the drive of the timing control unit, the switching array of the Floquet topology circuit layer can accurately control the charging and discharging process of the coupling capacitor, and thus realize the design principle of non-reciprocal transfer through synthetic spiral motion.

[0074] Figure 6 The results show that the ultra-wideband circulator of the present invention not only meets the non-reciprocal transmission characteristics requirement of the circulator in the 50MHz-1.8GHz frequency band, but also achieves the coordinated optimization of low insertion loss, high isolation and good port matching in ultra-wideband through precise timing control of the Floquet topology circuit layer.

[0075] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0076] Although this application has been described above with reference to specific embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of this application. In particular, as long as there is no structural conflict, the features in the specific embodiments disclosed in this application can be combined with each other in any way. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, this application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A periodic modulation topology based ultra-wideband circulator, comprising: It comprises a timing control unit (1), a Floquet topological circuit layer (2), a first coupling port (3), a second coupling port (4), a third coupling port (5), a clock signal driving module (6), a reset signal driving module (7) and an initiation signal driving module (8). The timing control unit (1) is connected with the Floquet topological circuit layer (2), the clock signal driving module (6), the reset signal driving module (7) and the initiation signal driving module (8) respectively. The other ends of the first coupling port (3), the second coupling port (4), the third coupling port (5), the clock signal driving module (6), the reset signal driving module (7) and the initiation signal driving module (8) are grounded respectively. The Floquet topological circuit layer (2) adopts a six-layer parallel network structure, each layer of the network structure comprising a coupling capacitor and three N-type MOSFET transistor switches, the first coupling port (3) being connected with the first N-type MOSFET transistor switch in each layer of the network structure, the second coupling port (4) being connected with the second N-type MOSFET transistor switch in each layer of the network structure, and the third coupling port (5) being connected with the third N-type MOSFET transistor switch in each layer of the network structure; the other ends of the three N-type MOSFET transistor switches in each layer of the network structure being connected with the coupling capacitor of the network structure respectively, and the coupling capacitor being grounded. The first coupling port (3) is composed of one resistor and one input pulse source, the second coupling port (4) is composed of one resistor, and the third coupling port (5) is composed of one resistor.

2. The ultra-wideband circulator based on a periodically modulated topology circuit according to claim 1, characterized in that, The timing control unit (1) generates six periodic pulse signals after receiving the clock driving signal, the reset driving signal and the initiation driving signal from the clock signal driving module (6), the reset signal driving module (7) and the initiation signal driving module (8), and the six periodic pulse signals are used for periodically modulating the Floquet topological circuit layer (2).

3. A UWB circulator based on a periodic modulation topology circuit according to claim 2, characterized in that, The frequency of the six periodic pulse signals generated by the timing control unit (1) is 500MHz, and the six periodic pulse signals are cyclically turned on with an interval of 0.25ns, which are used for staggered control of the on-off of the transistor switches in the Floquet topological circuit layer (2).

4. The ultra-wideband circulator based on a periodically modulated topology circuit according to claim 3, characterized in that, Wherein, C is the coupling capacitor value, and V is the voltage across the coupling capacitor.

5. A UWB circulator based on a periodically modulated topology according to claim 4, characterized in that, The timing control unit (1) generates a time-domain modulation function of a periodic pulse signal of an nth timing is represented as: where T mod is the modulation period, T slot is the on-time of a single time slot; is a rectangular pulse function representing the switching state of the MOSFET; is the delay time of the nth signal, k is the sequence number of the period, and t is the time. From the phase relationship, the expression is: wherein represents the phase of the nth signal, represents the initial phase.

6. A UWB circulator based on a periodically modulated topology according to claim 5, characterized in that, The Floquet topological circuit layer (2) is equivalent to a time-varying conductance network. According to Kirchhoff's law, the calculation formula of the instantaneous current between the first layer and the second layer is: ​ wherein, is the time-varying conductance of the transistor switch control between the first layer and the second layer, V i (t) is the voltage of the first layer at time t, V j (t) is the voltage of the second layer at time t.

7. A UWB circulator based on a periodically modulated topology according to claim 6, characterized in that, The one kind based on the cycle modulation topology circuit's ultra-wide band circulator is based on the quasi electrostatic wave principle, the energy storage density w of signal E The expression is obtained by the electric field energy domination: ​ 8. The ultra-wideband circulator based on a periodically modulated topology circuit according to claim 7, characterized in that, Group velocity of a kind of ultra-wideband circulator based on periodic modulation topology circuit The expression is determined by the modulation frequency: wherein is the modulation frequency.

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