CN-122026818-A - Electromagnetic wave broadband frequency shift conformal transmission method based on double-constitutive-parameter time-varying circuit

CN122026818ACN 122026818 ACN122026818 ACN 122026818ACN-122026818-A

Abstract

The invention discloses an electromagnetic wave broadband frequency shift conformal transmission method based on a double-constitutive-parameter time-varying circuit, and belongs to the technical field of microwave radio frequency, time metamaterial and frequency domain transformation. The method is realized based on a frequency shift transmission circuit, wherein the frequency shift transmission circuit comprises a microstrip transmission line and a periodically loaded inductance branch, and the inductance branch comprises a switch, a series inductance and a parallel inductance. When the pulse signal completely enters the microstrip transmission line, all the switches are closed at the same time, and frequency migration occurs due to conservation of wave numbers of the microstrip transmission line, so that frequency shift transmission is realized. The method does not depend on a complex local oscillation system, does not increase the complexity of excessive circuits and can not generate harmonic waves theoretically, so that the frequency migration, reflection-free efficient transmission and waveform-undistorted conformal effects of a broadband domain are realized, and a new technical path is provided for broadband and low-distortion signal processing in the microwave radio frequency domain.

Inventors

WANG YANGKAI
DUAN LONGJI
PENG JIE
XIONG JIANG

Assignees

电子科技大学

Dates

Publication Date: 20260512
Application Date: 20260410

Claims (6)

1. The electromagnetic wave broadband frequency shift conformal transmission method based on the double-constitutive-parameter time-varying circuit is characterized in that the method is realized based on a frequency shift transmission circuit, and the frequency shift transmission circuit comprises a microstrip transmission line and a periodically loaded inductance branch; The microstrip transmission line comprises a medium substrate, a microstrip line and a grounding plate, wherein the microstrip line and the grounding plate are respectively positioned on the upper surface and the lower surface of the medium substrate, an inductance branch is periodically loaded on the microstrip transmission line in a set length, the microstrip transmission line is divided into N sections, N is a positive integer, the inductance branch comprises a switch, a series inductance and a parallel inductance, one end of the switch is connected with the initial end of the microstrip line in the segmented microstrip transmission line, the other end of the switch is connected with one end of the series inductance, the other end of the series inductance is connected with the grounding plate, one end of the parallel inductance is connected to the connection point of the switch and the series inductance, when N epsilon [1, N-1], the other end of the parallel inductance corresponding to the nth section microstrip transmission line is connected to the connection point of the switch corresponding to the (n+1) th section microstrip transmission line, and when n=N, the other end of the parallel inductance corresponding to the nth section microstrip transmission line is connected to the tail end of the microstrip line in the microstrip transmission line through a tail end switch; The characteristic impedance of the microstrip transmission line is marked as Z 1 , and the characteristic impedance of the frequency shift transmission line is the Bloch impedance Z 2 in the state that all switches are closed, so that the condition Z 2 = Z 1 is satisfied; when the pulse signal completely enters the microstrip transmission line, all the switches are closed at the same time, and frequency migration occurs due to conservation of wave numbers of the microstrip transmission line, so that frequency shift transmission is realized.
2. The electromagnetic wave broadband frequency shift conformal transmission method based on the double constitutive parameter time varying circuit according to claim 1, wherein the electric length of the segmented microstrip transmission line is less than one eighth of the corresponding wavelength of the center frequency of the input pulse signal.
3. The electromagnetic wave broadband frequency shift conformal transmission method based on the double-constitutive-parameter time-varying circuit according to claim 1, wherein the following time boundary conditions exist before and after the switching time of all switches from open to closed: ; Wherein, the For the moment of switching of the switch, And Respectively representing the time before and after switching of the switch, wherein z is the transmission distance; And Respectively is Time of day and time of day The microstrip transmission line transmits the voltage at the location of the distance z, And Respectively is Time of day and time of day The current of the microstrip transmission line at the z position at the moment; according to the telegraph equation of the microstrip transmission line, the incident wave, the time reflected wave and the time transmitted wave are respectively expressed as: Incident wave: ; Time reflected wave: ; Time-transmitted wave: ; Wherein, the And The voltage and current of the incident wave respectively, Is a time variable; The frequency of the mobile transmission circuit is shifted for all switches open, The frequency of the mobile transmission circuit is changed when all switches are closed, k is wave number; And R and T are respectively a time reflection coefficient and a time transmission coefficient; And Voltage and current of time-transmitted waves, respectively; Substituting the incident wave, the time reflected wave and the time transmitted wave into the time boundary condition to obtain a time transmission coefficient T and a time reflection coefficient R which are respectively: ; as can be derived from the above equation, the time reflection coefficient R of the generated time boundary is 0 at the switch switching time of all switches from open to closed under the condition that Z 2 =Z 1 is satisfied.
4. The electromagnetic wave broadband frequency shift conformal transmission method based on the double-constitutive-parameter time-varying circuit according to claim 1, wherein when all switches are turned off, constitutive parameters of the frequency shift transmission circuit are as follows: ; Wherein, the And Respectively representing the dielectric constant and the magnetic permeability of the mobile transmission circuit when all the switches are disconnected; And Equivalent distributed capacitance and inductance of microstrip transmission line unit length; In order to achieve the light velocity, the light beam is, Is the equivalent dielectric constant of the microstrip transmission line; when all the switches are closed, the constitutive parameters of the frequency shift transmission circuit are as follows: ; Wherein, the And Respectively representing the dielectric constant and the magnetic permeability of the mobile transmission circuit when all the switches are closed, wherein omega is the frequency; Frequency mobility The method comprises the following steps: 。
5. the electromagnetic wave broadband frequency shift conformal transmission method based on the double-constitutive-parameter time-varying circuit according to claim 1, wherein the dielectric substrate has a relative permittivity of =4.4, Thickness of =1.575 The width of the microstrip line is =2.9 The characteristic impedance of the microstrip transmission line is Z 1 =51.37Ω.
6. The electromagnetic wave broadband frequency shift conformal transmission method based on the double-constitutive-parameter time-varying circuit according to claim 1, wherein in the inductance branch, the series inductance is =62.4 The parallel inductance is =99.84 。

Description

Electromagnetic wave broadband frequency shift conformal transmission method based on double-constitutive-parameter time-varying circuit Technical Field The invention belongs to the technical field of microwave radio frequency, time metamaterial and frequency domain transformation, and particularly relates to an electromagnetic wave broadband frequency shift conformal transmission method based on a double-constitutive-parameter time-varying circuit. Background In the fields of microwave radio frequency communication, radar detection, radio frequency measurement and the like, frequency conversion is a core link of signal processing, and the frequency of an input signal needs to be shifted to a target frequency band, and meanwhile, the integrity, broadband suitability and low loss of signal transmission need to be ensured. The conventional frequency conversion mainly depends on a mixer, and the technical maturity of the frequency conversion is high, but in recent years, defects which are difficult to overcome, such as narrow-band adaptive characteristics, harmonic generation caused by nonlinear characteristics, waveform distortion, obvious signal reflection, structure dependence on local oscillation signals, limited system compatibility and the like are gradually exposed. Therefore, when frequency shift design is performed, it is significant to solve the above problems. Some attempts have been made in the prior art to address the shortcomings of conventional mixers. The subharmonic mixer improves isolation by reducing local oscillator frequency requirements, but still does not break through the bottleneck of narrow-band frequency shift, and the problem of waveform distortion is not solved, the microwave photon mixer can realize ultra-wideband, but has high system complexity, high cost and large volume, and cannot be suitable for miniaturized and low-cost terminal equipment, and the conventional time metamaterial related research such as a time quarter-wave impedance converter tries to reduce reflection through time boundary regulation, but cannot realize the cooperative realization of broadband frequency shift and waveform shape retention. In summary, the existing frequency conversion technology cannot realize broadband frequency shift, no reflection, waveform shape retention, elimination of harmonic wave influence and low system complexity. Disclosure of Invention The invention aims to overcome the defects of the prior art and provide an electromagnetic wave broadband frequency shift conformal transmission method based on a double-constitutive-parameter time-varying circuit. The technical problems proposed by the invention are solved as follows: an electromagnetic wave broadband frequency shift conformal transmission method based on a double-constitutive-parameter time-varying circuit is realized based on a frequency shift transmission circuit, and the frequency shift transmission circuit comprises a microstrip transmission line and a periodically loaded inductance branch; The microstrip transmission line comprises a medium substrate, a microstrip line and a grounding plate, wherein the microstrip line and the grounding plate are respectively positioned on the upper surface and the lower surface of the medium substrate, an inductance branch is periodically loaded on the microstrip transmission line in a set length, the microstrip transmission line is divided into N sections, N is a positive integer, the inductance branch comprises a switch, a series inductance and a parallel inductance, one end of the switch is connected with the initial end of the microstrip line in the segmented microstrip transmission line, the other end of the switch is connected with one end of the series inductance, the other end of the series inductance is connected with the grounding plate, one end of the parallel inductance is connected to the connection point of the switch and the series inductance, when N epsilon [1, N-1], the other end of the parallel inductance corresponding to the nth section microstrip transmission line is connected to the connection point of the switch corresponding to the (n+1) th section microstrip transmission line, and when n=N, the other end of the parallel inductance corresponding to the nth section microstrip transmission line is connected to the tail end of the microstrip line in the microstrip transmission line through a tail end switch; The characteristic impedance of the microstrip transmission line is marked as Z 1, and the characteristic impedance of the frequency shift transmission line is the Bloch impedance Z 2 in the state that all switches are closed, so that the condition Z 2= Z1 is satisfied; when the pulse signal completely enters the microstrip transmission line, all the switches are closed at the same time, and frequency migration occurs due to conservation of wave numbers of the microstrip transmission line, so that frequency shift transmission is realized. Further, the electrical leng