73 results about "Terahertz pulse" patented technology

The utility model discloses a terahertz nondestructive testing robot for a wind power blade, and belongs to the technical field of wind power blade detection. Comprising a terahertz nondestructive testing assembly which emits terahertz pulse waves to scan the wind power blade and outputs sampling information; the defect labeling assembly is connected with the terahertz nondestructive testing assembly, and the defect labeling assembly is used for labeling the defect area of the wind power blade; the low-light night vision device is connected with the terahertz nondestructive testing assembly and outputs image information; a terahertz nondestructive testing assembly, a defect marking assembly and a low-light night vision device are arranged on the mobile platform. The technical scheme has the beneficial effects that by adopting the technical scheme, the detection accuracy can be improved, the detection efficiency is high, a person does not need to enter the blade, and the detection safety is ensured.

The invention relates to a hundred-milliwatt high-power high-repetition-frequency terahertz strong source generating device at room temperature, belongs to the technical field of nonlinear optical frequency conversion, and solves the problems that the terahertz conversion rate is low and additional cooling equipment is needed in the prior art. The beam expanding lens group is used for carrying out light spot beam expanding on the femtosecond pumping laser until the diameter of a light spot is twice of the original diameter; the plane mirror group is used for guiding the pump laser after beam expansion; the first half-wave plate, the reflective diffraction grating, the gold reflector and the third ultrafast reflector are used for adjusting polarization and diffraction reflection; the 4-f telescope imaging lens group is used for reducing the spot diameter of the received pump laser and imaging the pump laser to the lithium niobate crystal; the lithium niobate crystal generates terahertz pulse radiation in the direction perpendicular to the wavefront; the terahertz collection module receives and focuses the terahertz pulse radiation; and the measuring device is used for receiving the focused terahertz pulse radiation for measurement.

The invention provides a detection method of a flexible magnetic-field-free terahertz ultrafast light source and spin terahertz equipment. The detection method comprises the following steps: exciting an ultrafast terahertz light source device to generate an ultrafast terahertz pulse through a near-infrared ultrafast laser pulse, and detecting through a terahertz ultrafast spectrum. Meanwhile, a spinning THz source based on a transition metal oxide heterojunction without an external magnetic field, a flexible ultrafast spinning THz source based on inorganic substrate mica and a new method for widening the THz ultrafast pulse frequency domain width are achieved, and the spinning THz source which is low in energy consumption and practical is achieved.

The invention provides a detection system and method based on terahertz pulse on-chip radiation detection. The detection system and method can be applied to the technical field of terahertz nondestructive detection. The detection system comprises a terahertz pulse radiation unit, a pulse regulation and isolation unit and a terahertz pulse detection unit which are integrated on the same chip, the terahertz pulse radiation unit is used for radiating terahertz detection pulses under the action of the first femtosecond laser pulses; the pulse regulation and isolation unit is used for regulating the terahertz detection pulse input from the first port to be output through the third port and regulating the terahertz reflection pulse input from the third port to be output through the second port; and the terahertz pulse detection unit is connected with the second port and is used for detecting the terahertz reflected pulse to obtain a current signal, so that fault defect detection of the detected sample is realized based on the current signal. According to the detection system, damage to the integrated circuit structure in the detection process is avoided, and the problem of poor fault defect detection accuracy is solved.

The invention belongs to the technical field of terahertz, relates to terahertz communication, and particularly discloses a quasi-optical resonant cavity and a terahertz pulse compression system. According to the invention, the pulse generation module and the coupling compensation module are connected in parallel and are connected to the common reflector through the common coupler, so that function decoupling is realized. In a pulse compression stage, the common coupler introduces an incident terahertz wave beam into two optical paths, and destructive interference occurs between two paths of leakage signals by adjusting the coupling compensation module, so that zero coupling loss is realized, and the problem of large energy loss is solved. Meanwhile, the pulse generation module can independently adjust the optical path of the pulse generation module to control the pulse width, and the adjustment process does not affect the optimized interference condition, so that the high robustness of adjustment is ensured. In the output stage, energy is released by switching the state of the common coupler. Compared with the prior art, low-loss accumulation and robust pulse width continuous adjustment are realized at the same time, so that the terahertz pulse compression effect is remarkably improved.

The invention discloses a thickness detection method. The method comprises the following steps: acquiring a blank time-domain signal, a time-domain signal of a standard sample with known thickness and a time-domain signal of a sample to be detected based on a terahertz time-domain spectroscopy system; performing corresponding frequency domain transformation on the time domain signals, and calculating a refractive index corresponding to each frequency component in the terahertz pulse signal based on a result after the frequency domain transformation; performing signal energy weighted average on all refractive indexes to obtain an equivalent average refractive index; and calculating the thickness of the to-be-measured sample by using the equivalent average refractive index. According to the method, the time-domain signal is converted into the frequency-domain signal, corresponding calculation is carried out, the refractive indexes corresponding to different frequency components in the terahertz pulse signal are obtained, then energy weighted averaging is carried out on the refractive indexes, the more accurate equivalent average refractive index is obtained, and when the thickness is calculated on the basis of the equivalent average refractive index subsequently, the thickness of the terahertz pulse signal is calculated more accurately. The influence caused by the dispersion phenomenon is effectively eliminated, and a more accurate thickness detection effect is obtained.

The application provides a chip-scale package interconnection structure failure analysis method and device, comprising: determining the failure external pin corresponding to the failure CSP package interconnection structure according to the current-voltage characteristic curve corresponding to each external pin; collecting and analyzing the time-domain reflection waveform of the failure external pin by using the electro-optical terahertz pulse reflection technology, positioning the target interconnection failure area in the interconnection path where the failure external pin is located according to the amplitude, time delay and waveform distortion characteristics of the reflection pulse; scanning the target interconnection failure area by using the three-dimensional X-ray microscopic imaging technology, and determining the target position of the failure point on the interconnection path where the failure external pin is located and the corresponding structural defects based on the scanning result. The application realizes the non-destructive failure analysis of the CSP package interconnection structure by combining the electro-optical terahertz pulse reflection technology and the three-dimensional X-ray microscopic imaging technology, and improves the failure point fault positioning accuracy and efficiency.

This invention relates to a high-power, high-repetition-rate terahertz source generating device at room temperature with a capacity of hundreds of milliwatts, belonging to the field of nonlinear optical frequency conversion technology. It solves the problems of low terahertz conversion efficiency and the need for additional cooling equipment in existing technologies. The device comprises, arranged sequentially along the optical path: a pump laser for providing femtosecond pump laser light; a beam-expanding lens group for expanding the femtosecond pump laser beam to twice its original diameter; a plane mirror group for guiding the expanded pump laser; a first half-wave plate, a reflective diffraction grating, a gold mirror, and a third ultrafast mirror for adjusting polarization and diffraction reflection; a 4-f telescope imaging lens group for reducing the diameter of the received pump laser beam and imaging it onto a lithium niobate crystal; a lithium niobate crystal for generating terahertz pulse radiation perpendicular to the wavefront; a terahertz collection module for receiving and focusing the terahertz pulse radiation; and a measurement device for receiving and measuring the focused terahertz pulse radiation.

The invention discloses a terahertz pulse positioning method and system based on local symmetry, and the method comprises the steps: firstly constructing a terahertz pulse signal local symmetry degree function model, and carrying out the processing of a terahertz pulse signal, and obtaining a local symmetry degree function; all minimum value points of the local symmetry degree function are obtained through gradient calculation; and screening according to a threshold method to obtain a local symmetry degree function minimum value, and outputting a signal peak point and an edge point to realize terahertz pulse positioning. According to the terahertz pulse positioning method, the terahertz pulse signal local symmetry degree function model is constructed, and the peak point and the edge point of the signal are determined by adopting the threshold value method, so that the terahertz pulse signal is accurately positioned, and the robustness of the terahertz pulse positioning method is improved.

The present disclosure relates to the technical field of thin film material performance detection, and provides a method and system for testing complex permittivity of epitaxial thin film material in a terahertz frequency band, which comprises the following steps: performing transmission type testing on different transmission regions obtained by dividing a to-be-tested epitaxial thin film material sample and air, to obtain a time-domain waveform of a terahertz pulse transmission electric field; performing Fourier transform on the obtained time-domain waveform to obtain an amplitude spectrum and a phase spectrum of the electric field; calculating a complex refractive index of a substrate material according to the amplitude spectrum and the phase spectrum; constructing a transmission and reflection model for the substrate plus the epitaxial thin film material by taking into account multiple reflections inside the substrate material; obtaining a relationship between the complex permittivity of the epitaxial thin film material and the complex refractive index of the substrate material based on the transmission and reflection model, and inversely calculating the complex permittivity of the epitaxial thin film material. In the process of testing the complex permittivity of the epitaxial thin film material, the testing error introduced by multiple reflections inside the substrate material is taken into account, thereby improving the testing accuracy of the complex permittivity of the material.

The invention discloses a method and system for measuring the dielectric constant of a material, and the method comprises the steps: enabling a terahertz pulse signal to flow through a transmission line and generate reflection through growing a coplanar waveguide transmission line on the surfaces of an electro-optical crystal and a measured material; after femtosecond laser is processed, a terahertz signal is sampled, an optical polarization state analysis system reproduces an electric signal and extracts a peak moment, and a relative dielectric constant is calculated by combining transmission line structure parameters and a formula. According to the invention, electro-optical sampling and time domain reflection technologies are combined, high time resolution and structure adaptability are realized, and accurate measurement of the dielectric constant of the material is realized.

The application discloses a polarization-adjustable multi-period terahertz pulse generation method, and relates to the technical field of terahertz, and comprises the following steps: femtosecond laser emitted by a femtosecond laser is expanded into a large light spot and is collimated after passing through a concave lens and a first off-axis parabolic mirror, and irradiates on a terahertz source film in a terahertz pulse source, so that a terahertz pulse train with a certain time delay is generated, and then the terahertz pulse train is focused through a second off-axis parabolic mirror, and a multi-period terahertz pulse with spatial coincidence is formed at a focal point. The terahertz source film is distributed along the steps through the insulating stepped substrate, and the polarization state of the multi-period terahertz pulse can be changed by changing the magnetic field applied to the terahertz source film through an external magnetic field, and the center frequency of the multi-period terahertz pulse can be changed by changing the step height; and the application has the advantages of simple structure, convenient operation, polarization adjustment, and large frequency adjustment range.

The invention discloses a near-field terahertz nonlinear optical effect excitation detection method and system. A femtosecond laser space-time shaping technology is combined, a strong terahertz pulse is generated based on a femtosecond laser filament, the strong terahertz pulse is coupled with a tapping mode atomic force microscope, and space-time matching of probe vibration and the terahertz pulse is accurately controlled by using a synchronous sampling method, so that the time-space matching of the probe vibration and the terahertz pulse is realized. Mismatch between the low-repetition-frequency strong-field terahertz pulse and the vibration frequency of the near-field microscope probe is overcome, and strong-field terahertz near-field coupling and detection are achieved. The local field enhancement effect of the tip of the nanoprobe can realize nanoscale focusing (peak field intensity reaches MV / cm magnitude) of a terahertz field at a probe-sample gap, the near-field nonlinear interaction is remarkably enhanced, the diffraction limit is broken through, and the nanoscale spatial resolution is realized. According to the method, the excitation detection efficiency and the spatial resolution of the terahertz nonlinear effect are remarkably improved, and accurate excitation, characterization and regulation of the nonlinear optical effect of the sample can be realized.

The invention discloses a simulation method and device for electromagnetic wave transmission characteristics in dust plasma, and belongs to the technical field of electromagnetic simulation. The method comprises the following steps: acquiring feature distribution data of dust plasma in a reaction cavity of a dust plasma simulation model; wherein the dust plasma is obtained by performing electrochemical reaction on reaction gas and dust particles in the reaction cavity, and each dust particle is placed at a random position of a pre-divided virtual grid of the reaction cavity; calculating electromagnetic field distribution of electromagnetic waves in the dust plasma according to the characteristic distribution data of the dust plasma; and determining transmission characteristics of electromagnetic waves in the dust plasma according to the electromagnetic field distribution. The invention can effectively overcome the practical difficulties that the current dust plasma is difficult to prepare in a laboratory, and the terahertz pulse spectrum transmission measurement system is small in dynamic range, high in complexity and difficult to be fused with a huge plasma generation system for combined measurement.

The application provides a high-resolution near-field terahertz time-domain spectroscopy system and a high-precision tomography method, which comprises: a first terahertz source and a second terahertz source for generating a first terahertz pulse and a second terahertz pulse under the triggering of a first pulsed laser and a second pulsed laser respectively; a terahertz detector for receiving a third terahertz pulse and a fourth terahertz pulse generated by the radiation of a sample under the triggering of a third pulsed laser; the third terahertz pulse and the fourth terahertz pulse are generated by the radiation of the sample to the first terahertz pulse and the second terahertz pulse respectively; a pulsed laser light path for transmitting the first pulsed laser, the second pulsed laser and the third pulsed laser; the distance between the sample and the first terahertz source, the distance between the sample and the second terahertz source and the distance between the sample and the terahertz detector are all less than the terahertz wavelength. The application simultaneously utilizes near-field radiation technology and near-field detection technology to improve the resolution of the system and reduce the terahertz transmission loss.

The present application relates to the technical field of terahertz pulse generation of optoelectronics, and discloses a terahertz field generation method based on two-color field phase locking, comprising: through optical system building, using a beam expander to amplify the fringe spot in the optical path. The frequency map and phase map of the amplified spot are obtained, and the periodic frequency point is extracted. The phase change information of the periodic frequency point is analyzed, compared with the expected phase change threshold, and it is judged whether the position of the piezoelectric ceramic needs to be adjusted. If the phase change information is within the threshold range, it is determined that no adjustment is needed; otherwise, the position of the piezoelectric ceramic is adjusted and moved. Through accurate control of the phase of the optical field, the stability of the pulse is improved, the overall structure is simplified, and the cost of the terahertz magnetic field generation is reduced.

The invention relates to a gene marker detection method based on a terahertz signal, which comprises the following steps: irradiating a to-be-detected gene sample by using a terahertz pulse, and acquiring the terahertz signal generated after the gene sample is reflected; performing denoising processing on the terahertz signal to obtain a denoised terahertz signal; establishing a database according to a signal of a known gene marker in a terahertz wave band; comparing the current gene sample with the terahertz signal of the gene marker in the database to obtain a similar value; and when the similarity value exceeds a preset threshold value, determining that the current gene sample has a corresponding gene marker. According to the method, the specific terahertz signal database of the gene markers is established, and the current gene sample is compared with the terahertz signals of the gene markers in the database, so that the requirements of clinical and laboratory on rapid detection of the gene markers can be met, and the detection accuracy and reliability are greatly improved.

The application belongs to the technical field of terahertz pulse source generation, and provides a patterned wave front regulation method of a terahertz spin emitter. According to the patterned design, the method arranges a plurality of sequential terahertz spin film units and a plurality of reverse sequential terahertz spin film units in the terahertz spin emitter in space to obtain a terahertz light beam with a desired shape, realize spatial phase coding of the terahertz light field, and thus complete wave front regulation. Compared with the prior art, the application has the advantages of strong operability, wide applicability, low cost and the like.

The invention relates to the technical field of equipment detection, in particular to an insulating oil aging marker detection system and method and a storage medium, and the system is characterized in that laser generated by a laser device is split into a first light beam and a second light beam through a spectroscope, and the first light beam excites a photoconductive antenna to generate terahertz pulses; the terahertz pulse enters the first reflection assembly, and the first reflection assembly reflects the terahertz pulse to a sample in the sample pool; the acquisition assembly acquires a time domain signal after mixing the terahertz pulse absorbed by the sample and the second light beam; and the processing assembly performs fitting according to the terahertz pulse absorbed by the sample and the time domain signal after the second light beam is mixed to obtain a terahertz absorption spectrum, and analyzes the insulating oil aging marker of the sample according to the terahertz absorption spectrum. Therefore, the problems that a detection mode in the related technology is difficult to meet on-site rapid and real-time intelligent monitoring requirements, the detection period is long and the like are solved.

The invention discloses a film coating device for filter film production based on an electrostatic film coating method, relates to the technical field of filter films, and provides the following scheme aiming at the problems that a base material provided by the background technology is easy to form secondary pollution, the base material cannot be subjected to real-time dust removal treatment, slurry cannot be stably attached to the base material, and the film coating effect is poor. Comprising a base and a base material, the mounting mechanism comprises two mounting seats which are respectively connected to the outer wall of the top of the base through bolts, and two ultrasonic dust removers which are respectively connected to the outer walls of the opposite sides of the two mounting seats through bolts; the two atomization depositor and the two terahertz pulse irradiator are respectively connected to the outer walls of the opposite sides of the two mounting seats through bolts. According to the device, dust attached to a base material can be cleaned in real time, secondary pollution of the base material in the conveying process is prevented, the situation that slurry cannot be stably attached to the base material is avoided, and the film coating effect is improved.

The invention relates to a cookware recognition device, a kitchen range and a range hood, and the cookware recognition device is characterized by comprising a terahertz transmitting and receiving sensor which is arranged near a combustor of the kitchen range and can transmit terahertz pulse signals to cookware arranged above the combustor of the kitchen range, the first echo signal is directly reflected back from the outer surface of the cookware, and the second echo signal is reflected back from the inner surface of the cookware after the terahertz pulse signal penetrates through the wall of the cookware; the signal analysis module is used for processing the second echo signal detected by the terahertz transceiving sensor and judging the specific material of the cookware according to the phase difference between the transmitted terahertz pulse signal and the received second echo signal; and the signal sending module is connected with the signal analysis module and is used for sending the specific material of the cookware placed above the cooker burner to the cooker or the range hood. Compared with the prior art, the material of the cookware can be identified without a built-in chip.

The invention discloses a terahertz wave pulse emitter based on a ferromagnetic heterojunction. The terahertz wave pulse emitter mainly comprises a substrate, a reflecting layer, the ferromagnetic heterojunction, a spacing layer, microspheres, a conductive layer, a rear cover and an anti-reflection layer. In addition, the invention further provides a manufacturing method of the terahertz wave pulse transmitter based on the ferromagnetic heterojunction. By irradiating the terahertz wave pulse emitter based on the ferromagnetic heterojunction with femtosecond laser, terahertz pulses with high peak field intensity can be generated. The terahertz wave pulse emitter provided by the invention has the advantages of simple structure and large spectral bandwidth, and is suitable for the fields of terahertz wave imaging, security and protection and the like.

The invention discloses a terahertz pulse width regulation and control method based on Co / Ru heterojunction, and belongs to the technical field of terahertz photoelectrons. The method comprises the steps of substrate treatment, Co / Ru heterojunction thin film preparation, terahertz emission and detection light path establishment, signal acquisition and treatment and pulse width regulation and control. Sequentially depositing a Co layer and a thickness-adjustable Ru layer on the substrate through magnetron sputtering to form a Co / Ru heterojunction; a femtosecond laser is utilized to excite a heterojunction to generate terahertz pulses, an electro-optical sampling system is utilized to collect time domain signals, and Hilbert transform is adopted to extract pulse width and delay time; based on the monotonic corresponding relation between the thickness of the Ru layer and the terahertz pulse width, continuous adjustment of the pulse width within the range of 100-500 fs is achieved by adjusting the thickness of the Ru layer, and meanwhile the spectral bandwidth and the peak delay time are synchronously regulated and controlled.

The present application relates to the technical field of terahertz wave detection imaging, and particularly relates to an artificial intelligence enhanced strong field terahertz spectroscopy detection imaging device and method, which comprises a femtosecond laser, a beam splitter, a chopper, a laser spot beam expander module, a spin terahertz emitter, a transmission-reflection integrated automatic scanning detection module, a terahertz detection device, and an artificial intelligence enhanced thickness measurement module and an artificial intelligence enhanced defect detection imaging module; the laser emitted by the femtosecond laser generates pump light and detection light by the beam splitter, the pump light sequentially passes through the laser spot beam expander module, the spin terahertz emitter and the transmission-reflection integrated automatic scanning detection module to enter the terahertz detection device; the detection light passes through the transmission-reflection integrated automatic scanning detection module to enter the terahertz detection device, the terahertz detection device outputs a terahertz pulse shape, and finally the sample thickness or defect profile is obtained; the present application can improve the sample defect detection efficiency and reduce the cost.

The invention discloses a porcelain post insulator defect nondestructive testing device, which comprises a femtosecond laser, a spectroscope, a chopper, a time delay device, a terahertz radiation source, a polarization focusing device, a transmission detection device and a lock-in amplifier, the chopper receives a pump pulse generated by the spectroscope, and the polarization focusing device receives a detection pulse generated by the spectroscope; a time delay device is arranged between the chopper and the terahertz radiation source, pulses of the polarization focusing device and the terahertz radiation source are emitted into the transmission detection device, the lock-in amplifier is respectively connected with the chopper and the transmission detection device, and the lock-in amplifier is connected with an external computer. According to the method, the terahertz pulse time domain information of the porcelain post insulator is obtained by analyzing and processing the complex dielectric function space distribution information of the sample contained in the intensity and phase of the terahertz wave pulse transmitted by the porcelain post insulator, so that the non-power-off nondestructive detection of the porcelain insulator can be realized, and the detection efficiency of the porcelain insulator defect is greatly improved.

The application provides a method for generating a multi-pulse terahertz beam with adjustable time interval of single pulse, which comprises the following steps: generating a pulse signal from a same terahertz wave source, then generating two or more pulse signals with consistent performance parameters through beam distribution, generating time interval through different time delay paths, and achieving the detection purpose by hitting the same detection area of the same research object. The method is based on the high-speed and high-precision modulation technology of the terahertz pulse of the pulse beam quasi-optical slow wave generator, and can realize the adjustment of the time interval of the pulse beam.

A tomographic atom probe includes an analysis chamber intended to analyze a sample of material in the form of a nanotip mounted on an anti-vibration support, the nanotip being brought to a temperature of between 0 kelvin and ambient temperature, the nanotip being biased at an adjustable voltage of between 1 kV and 15 kV, the analysis chamber comprising a position-sensitive and time of flight-sensitive ion detector. The atom probe comprises a generator for generating high-peak-intensity single-cycle ultrashort terahertz pulses, the analysis chamber comprising optical means for focusing the terahertz pulses, the focusing of the terahertz pulses causing the atoms of the nanotip to evaporate through the field effect without thermal effects. The terahertz pulses are generated by a femtosecond pulsed laser emitting very high-power ultrashort optical pulses at a high rate.

The application provides a transverse high-resolution terahertz time-domain spectrum imaging method and system, and relates to the technical field of terahertz imaging. The method comprises the following steps: obtaining a terahertz time-domain pulse sampling signal; performing Fourier transform on the terahertz time-domain pulse sampling signal to obtain a frequency spectrum; performing inverse Fourier transform on the frequency spectrum after high-pass filtering and low-pass filtering processing to obtain a time-domain signal; establishing a point spread function; performing deconvolution operation on the time-domain signal and the time-domain form of the established point spread function to obtain an image reconstruction signal; and determining a transverse high-resolution terahertz time-domain spectrum image according to the image reconstruction signal of each sampling point in a scanning area and the time of flight of the terahertz pulse wave. Through the method, image blurring caused by terahertz beam distortion can be better eliminated, and the transverse resolution of the terahertz imaging system and the quality of the reconstructed image can be improved.

A diffractive network is disclosed that utilizes, in some embodiments, diffractive elements, which are used to shape an arbitrary broadband pulse into a desired optical waveform, forming a compact and passive pulse engineering system. The diffractive network was experimentally shown to generate various different pulses by designing passive diffractive layers that collectively engineer the temporal waveform of an input terahertz pulse. The results constitute the first demonstration of direct pulse shaping in terahertz spectrum, where the amplitude and phase of the input wavelengths are independently controlled through a passive diffractive device, without the need for an external pump. Furthermore, a modular physical transfer learning approach is presented to illustrate pulse-width tunability by replacing part of an existing diffractive network with newly trained diffractive layers, demonstrating its modularity. This learning-based diffractive pulse engineering framework can find broad applications in e.g., communications, ultra-fast imaging and spectroscopy.

The application discloses a kind of based on Co / Ru heterojunction terahertz pulse width's regulation and control method, belong to terahertz optoelectronic technical field.The method includes: substrate processing, Co / Ru heterojunction film preparation, terahertz emission and detection optical path establishment, signal acquisition processing and pulse width regulation and control.Co layer and the Ru layer of adjustable thickness are sequentially deposited on substrate by magnetron sputtering, and Co / Ru heterojunction is formed;Terahertz pulse is generated by using femtosecond laser excitation heterojunction, time-domain signal is collected by electro-optic sampling system, and pulse width and delay time are extracted by using Hilbert transform;Based on the monotonic correspondence between Ru layer thickness and terahertz pulse width, the pulse width is continuously adjustable in the range of 100-500fs by adjusting the thickness of Ru layer, while the spectral bandwidth and peak delay time are simultaneously regulated.