CN217238509U

CN217238509U - Quasi-optical system for terahertz waves

Info

Publication number: CN217238509U
Application number: CN202220199830.1U
Authority: CN
Inventors: 刘晓方; 李朝波; 王冬宁; 吴延高
Original assignee: Shanghai Leitan Technology Co ltd
Current assignee: Shanghai Leitan Technology Co ltd
Priority date: 2022-01-25
Filing date: 2022-01-25
Publication date: 2022-08-19
Anticipated expiration: 2032-01-25

Abstract

The utility model discloses a quasi-optical system for terahertz wave, which adopts a first holophote, a filter and a third holophote arranged on a straight line, the filter is obliquely arranged, the reflecting surfaces of the first total reflecting mirror and the third total reflecting mirror face the filter, the second total reflecting mirror is arranged on the side of the filter relative to the filter, electromagnetic waves emitted from the 183GHZ feed source and the 325GHZ feed source are synthesized into one light path or the electromagnetic waves received from the antenna are divided into two light paths of the 183GHZ electromagnetic waves and the 325GHZ electromagnetic waves and then are respectively sent to the two 183GHZ feed sources and the 325GHZ feed sources, so that the distortion and cross polarization components of the beam after transmission through the reflecting mirror are small, and compared with the traditional waveguide technology, the power of the electromagnetic waves received by the feed source machine can be improved, the traditional waveguide power distribution technology is not needed, and meanwhile, the space occupied by the microwave device is reduced.

Description

Quasi-optical system for terahertz waves

Technical Field

The utility model belongs to the technical field of terahertz remote sensing surveys, specifically speaking relates to a quasi-optical system for terahertz wave.

Background

THz (terahertz) waves are between microwaves and light waves, have quasi-optical characteristics close to light waves and have obvious characteristics of microwaves, so that the THz waves have obvious advantages in certain fields.

The THz wave can be converged due to the light wave characteristic, and the divergent light can be converged into a light beam by using a lens; the microwave characteristics of the THz wave include a shorter wavelength, a larger bandwidth and a more specific action with the atmosphere; due to the fact that the wavelength is short, THz wave system components are small in size and light in weight, and the beam width narrower than that of microwaves can be obtained, so that high resolution and tracking accuracy are provided for target tracking and identification; the larger frequency bandwidth can obtain higher information transmission rate, and meet the requirement of very fast information processing speed required by precision tracking and target identification; in addition, compared with light waves and infrared rays, the THz wave attenuation is lower under the severe weather conditions with heavier suspended particles, dust or smoke, so that the THz wave system is more suitable for working under the severe weather conditions.

In the THz wave frequency band, the loss of the waveguide, the microstrip line and the like is large, the cost is high, and the manufacture is difficult, and the quasi-optical method can focus a wave beam on another reflector or lens by utilizing the reflector or the lens so as to form a wave beam waveguide, so that based on the quasi-optical method, a free space Gaussian wave beam method can be utilized to transmit signals, a metal or medium transmission line generating loss is removed, the loss is greatly reduced, and the effect is improved. In addition, the quasi-optical system can simultaneously process a plurality of different beams while maintaining the independent characteristics of the Gaussian beams, which is not possible with the conventional THz wave device. The THz wave solid-state component designed by the quasi-optical method has the advantages of wide bandwidth, good electromagnetic interference resistance, compact design and the like, can conveniently realize broadband power synthesis/distribution, can almost completely separate control/controlled devices, and enables the THz wave technology to become an important development direction in earth meteorology remote sensing detection, astronomical observation, material detection, medical imaging and short-distance communication systems.

SUMMERY OF THE UTILITY MODEL

The utility model aims at 183GHZ, 325GHZ frequency channel, provide a speculum arrangement structure to adopt the frequency selective surface to carry out the separation and the synthesis of different frequency wave bundles, realize a binary channels be used for terahertz wave's quasi-optical system.

The utility model discloses a following technical scheme realizes:

proposed is a quasi-optical system for terahertz waves, comprising: 183GHZ feed source, 325GHZ feed source, first total reflector, second total reflector, filter and third total reflector; the filter adopts a frequency selective surface to transmit 183GHZ electromagnetic waves and totally reflect 325GHZ electromagnetic waves; the first total reflector, the filter and the third total reflector are arranged on the same straight line, the filter is arranged in an inclined mode, and the reflecting surfaces of the first total reflector and the third total reflector face the filter; the second holophote is arranged at the side of the filter relative to the filter; electromagnetic waves received from an antenna are transmitted to the third total reflecting mirror and transmitted to the filter through the reflection of the third total reflecting mirror, 183GHZ electromagnetic waves are transmitted to the first total reflecting mirror through the frequency selection surface, and 325GHZ electromagnetic waves are transmitted to the second total reflecting mirror after being totally reflected by the frequency selection surface; 183GHZ electromagnetic waves are received by the 183GHZ feed source after being reflected by the first total reflector, and 325GHZ electromagnetic waves are received by the 325GHZ feed source after being reflected by the second total reflector; or, 183GHZ electromagnetic waves emitted by the 183GHZ feed source are reflected by the first total reflector and then emitted to the filter, and are emitted to the third total reflector after transmitting the frequency selection surface, 325GHZ electromagnetic waves emitted by the 325GHZ feed source are reflected by the second total reflector and then emitted to the filter, and are emitted to the third total reflector after being totally reflected by the frequency selection surface, and the 183GHZ electromagnetic waves and the 325GHZ electromagnetic waves are synthesized into one path and then reflected to the antenna by the third total reflector.

Further, the first total reflector, the filter and the third total reflector are arranged on a first straight line, the third total reflector and the filter are arranged on a second straight line, and an included angle of 60 degrees is formed between the first straight line and the second straight line.

Furthermore, the frequency selective surface is realized by adopting linear dipole units, the length is 0.8mm, the width is 0.1mm, the distance between each unit column is 0.2mm, and the distance between each unit row is 10 mm.

Further, the quasi-optical system further comprises: and the incident surface of the adjusting reflector group is arranged opposite to the third total reflector, and the emergent surface of the adjusting reflector group is opposite to the reflecting surface of the antenna.

Further, the adjusting mirror group includes: the fourth total reflector is arranged opposite to the third total reflector; the fifth total reflector is arranged opposite to the fourth total reflector; 183GHZ electromagnetic waves and 325GHZ electromagnetic waves which are synthesized to one optical path by the third total reflecting mirror are adjusted by the fourth total reflecting mirror and the fifth total reflecting mirror and then irradiated to the antenna reflecting surface.

Further, the first total reflector, the second total reflector and the third total reflector are all ellipsoidal total reflectors.

Further, the 183GHZ feed source and the 325GHZ feed source adopt a corrugated horn feed source.

Further, the fourth holophote is an ellipsoidal holophote, and the fifth holophote is a paraboloidal holophote.

Compared with the prior art, the utility model discloses an advantage is with positive effect: the utility model provides a quasi-optical system for terahertz wave, adopt three holophotes, a wave filter that separates and synthesize the wave beam of different frequencies by the frequency selective surface realizes, adopt first holophote, wave filter and third holophote set up on a straight line, and the wave filter slope sets up, the plane of reflection of first holophote and third holophote all faces the wave filter, the relative wave filter of second holophote sets up the structure in the avris of wave filter, will respectively from the electromagnetic wave synthesis of 183GHZ feed and 325GHZ feed transmission to a light path or will be from the electromagnetic wave of antenna receipt divide into after two light paths of 183GHZ electromagnetic wave and 325GHZ electromagnetic wave respectively give two 183GHZ feed and 325GHZ feed, make the wave beam distortion and cross polarization component less after the transmission of speculum, and compare with traditional waveguide technique, can improve the electromagnetic wave power that the feed machine received, the traditional waveguide power distribution technology is not needed, and meanwhile, the space occupied by the microwave device is reduced.

Furthermore, in the application, the filter is realized by adopting a frequency selective surface, so that the quasi-optical system has better beam efficiency and smaller beam distortion.

Other features and advantages of the present invention will become more apparent from the following detailed description of embodiments of the invention, which is to be read in connection with the accompanying drawings.

Drawings

Fig. 1 is a schematic optical path diagram of a quasi-optical system for terahertz waves according to the present invention;

fig. 2 is a diagram illustrating a far-field simulation result when f is 183GHZ and phi is 0 in the optical path shown in fig. 1;

fig. 3 is a diagram illustrating a far-field simulation result when f is 183GHZ and phi is 90 in the optical path shown in fig. 1;

fig. 4 is a diagram illustrating a far-field simulation result when f is 325GHZ and phi is 0 in the optical path shown in fig. 1;

fig. 5 is a diagram illustrating a far-field simulation result when f is 325GHZ and phi is 90 in the optical path shown in fig. 1;

fig. 6 is a schematic diagram of a design structure of a frequency selective surface in the filter according to the present invention;

fig. 7 is a schematic diagram of a simulation of a frequency selective surface in a filter according to the present invention;

fig. 8 is a schematic view of a combined optical path of a quasi-optical system for terahertz waves according to the present invention;

fig. 9 is a diagram illustrating far-field simulation results when f is 183GHZ and phi is 0 in the joint optical path shown in fig. 2;

fig. 10 is a diagram illustrating a far-field simulation result when f is 183GHZ and phi is 90 in the joint optical path shown in fig. 2;

fig. 11 is a diagram illustrating a far-field simulation result when f is 325GHZ and phi is 0 in the joint optical path shown in fig. 2;

fig. 12 is a diagram illustrating a far-field simulation result when f is 325GHZ and phi is 90 in the joint optical path shown in fig. 2.

Detailed Description

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

As shown in fig. 1, the quasi-optical system for terahertz waves proposed by the present application includes: 183GHZ feed source 1, 325GHZ feed source 2, first total reflector 3, second total reflector 4, filter 5 and third total reflector 6; the filter 5 is a filter that transmits 183GHZ electromagnetic waves and totally reflects 325GHZ electromagnetic waves by using a frequency selective surface.

The first total reflector 3, the filter 5 and the third total reflector 6 are arranged on a straight line, the filter 5 is obliquely arranged, and the reflecting surfaces of the first total reflector 3 and the third total reflector 6 face the filter 5; the second total reflection mirror 4 is provided on the side of the filter 5 opposite to the filter 5.

Specifically, the first total reflector 3, the filter 5 and the third total reflector 6 are disposed on a first straight line L1, the third total reflector 6 and the filter 5 are disposed on a second straight line L2, and an included angle of 60 ° is formed between the first straight line L1 and the second straight line L2.

Taking the example of combining two channels of electromagnetic waves into one light path for emission, the 183GHZ feed source 1 is parallel to the second straight line L2 in the emitting or receiving direction and is arranged toward the first total reflector 3, after the 183GHZ electromagnetic wave emitted by the 183GHZ feed source is reflected by the first total reflector 3, the reflected signal is emitted to the filter 5 along the first straight line L1, and is emitted to the third total reflector 6 after being transmitted by the frequency selection surface; the exit or receiving direction of the 325GHZ feed source 2 forms an included angle of 60 degrees with a second straight line L2 and is arranged towards the second total reflecting mirror 4, the exit 325GHZ electromagnetic wave is reflected by the second total reflecting mirror 4, the reflected signal is emitted to the filter 5 along the direction of a second straight line L2, and is emitted to the third total reflecting mirror 6 after being totally reflected by the frequency selection surface; the third total reflection mirror 6 combines the 183GHZ electromagnetic wave and the 325GHZ electromagnetic wave into a path and reflects the path to the antenna.

Taking the example of separating the electromagnetic wave received from the antenna into two-channel electromagnetic wave signals as an example, the electromagnetic wave received from the antenna is transmitted to the third total reflecting mirror 6, and is transmitted to the filter 5 through the reflection of the third total reflecting mirror 6, the 183GHZ electromagnetic wave transmission frequency selection surface is transmitted to the first total reflecting mirror 3, and the 325GHZ electromagnetic wave is transmitted to the second total reflecting mirror 4 after being totally reflected by the frequency selection surface; 183GHZ electromagnetic waves are reflected by the first total reflecting mirror 3 and then received by the 183GHZ feed source 1, and 325GHZ electromagnetic waves are reflected by the second total reflecting mirror 4 and then received by the 325GHZ feed source 2.

In some embodiments of the present application, the first total reflecting mirror 3, the second total reflecting mirror 4 and the third total reflecting mirror 6 are all ellipsoidal total reflecting mirrors; the 183GHZ feed 1 and the 325GHZ feed 2 both use a corrugated horn feed, as shown in fig. 2 to 5, which are simulation diagrams of the quasi-optical system, and include: the far-field simulation result when f is 183GHZ and phi is 0, the far-field simulation result when f is 183GHZ and phi is 90, the far-field simulation result when f is 325GHZ and phi is 0, and the far-field simulation result when f is 325GHZ and phi is 90.

In the embodiment of the application, the frequency selective surface is realized by adopting a linear dipole unit, and the size of the dipole unit is estimated according to the following theory: the central frequency is 1.6mm for the gaussian wavelength of 183GHZ, will resonate when the dipole length is about gaussian wavelength half, and effectual scattering, so set up the dipole length to be 0.8mm, the dipole theoretically should be infinitely small for the width, accomplish the minimum in the actual design as far as possible, this application embodiment adopts the width to be 0.1mm, the interval design between each dipole unit is: the column pitch is 0.2mm, the row pitch is 10mm, the designed structure is shown in fig. 6, and the frequency selection simulation result is shown in fig. 7.

In some embodiments of the present application, the quasi-optical system for terahertz waves further includes an adjusting mirror group, an incident surface of which is disposed opposite to the third total reflector 6, and an exit surface of which is disposed opposite to the reflecting surface of the antenna, so as to adjust an incident angle of the electromagnetic waves received by the antenna, and to adjust an exit angle of the electromagnetic waves synthesized after being emitted by the two feed sources, so as to adapt to different antenna design structures.

In one embodiment of the present application, as shown in fig. 8, the adjusting mirror group comprises: a fourth total reflector 7 and a fifth total reflector 8, wherein the fourth total reflector 7 is arranged opposite to the third total reflector 6, and the fifth total reflector 8 is arranged opposite to the fourth total reflector 7; the 183GHZ electromagnetic wave and the 325GHZ electromagnetic wave which are synthesized on one light path by the third total reflecting mirror 6 are adjusted by the fourth total reflecting mirror 7 and the fifth total reflecting mirror 8 and then irradiated to the reflecting surface of the antenna.

In some embodiments of the present application, the fourth total reflecting mirror 7 is an ellipsoidal total reflecting mirror, and the fifth total reflecting mirror 8 is a paraboloidal total reflecting mirror, as shown in fig. 9 to 12, which are joint simulation diagrams of the collimating optical system, including: the far-field simulation result when f is 183GHZ and phi is 0, the far-field simulation result when f is 183GHZ and phi is 90, the far-field simulation result when f is 325GHZ and phi is 0, and the far-field simulation result when f is 325GHZ and phi is 90.

The specific arrangement pitch, angle, etc. between the devices proposed in the embodiments of the present application can be implemented by those skilled in the art based on the existing measurement and process means in the design process of a specific product based on the quasi-optical system architecture proposed in the above application, and the application is not particularly limited.

It should be noted that the above description is not intended to limit the present invention, and the present invention is not limited to the above examples, and the changes, modifications, additions or substitutions made by those skilled in the art within the spirit of the present invention should also belong to the protection scope of the present invention.

Claims

1. A quasi-optical system for terahertz waves, comprising: the feed source is 183GHZ, the feed source is 325GHZ, the first holophote, the second holophote, the filter and the third holophote; the filter adopts a frequency selective surface to transmit 183GHZ electromagnetic waves and totally reflect 325GHZ electromagnetic waves;

the first total reflector, the filter and the third total reflector are arranged on the same straight line, the filter is arranged in an inclined mode, and the reflecting surfaces of the first total reflector and the third total reflector face the filter; the second holophote is arranged at the side of the filter relative to the filter;

electromagnetic waves received from an antenna are transmitted to the third total reflecting mirror and transmitted to the filter through the reflection of the third total reflecting mirror, 183GHZ electromagnetic waves are transmitted to the first total reflecting mirror through the frequency selection surface, and 325GHZ electromagnetic waves are transmitted to the second total reflecting mirror after being totally reflected by the frequency selection surface; the 183GHZ electromagnetic wave is reflected by the first total reflector and then received by the 183GHZ feed source, and the 325GHZ electromagnetic wave is reflected by the second total reflector and then received by the 325GHZ feed source; or, 183GHZ electromagnetic waves emitted by the 183GHZ feed source are reflected by the first total reflector and then emitted to the filter, and are emitted to the third total reflector after transmitting the frequency selection surface, 325GHZ electromagnetic waves emitted by the 325GHZ feed source are reflected by the second total reflector and then emitted to the filter, and are emitted to the third total reflector after being totally reflected by the frequency selection surface, and the 183GHZ electromagnetic waves and the 325GHZ electromagnetic waves are synthesized into one path and then reflected to the antenna by the third total reflector.

2. The quasi-optical system for terahertz waves according to claim 1, wherein the first total reflecting mirror, the filter and the third total reflecting mirror are disposed on a first straight line, the third total reflecting mirror and the filter are disposed on a second straight line, and the first straight line and the second straight line form an included angle of 60 °.

3. The quasi-optical system for terahertz waves of claim 1, wherein the frequency selective surface is implemented with linear dipole elements having a length of 0.8mm, a width of 0.1mm, a cell column pitch of 0.2mm, and a cell row pitch of 10 mm.

4. The quasi-optical system for terahertz waves of claim 1, further comprising:

and the incidence surface of the adjusting reflector group is arranged opposite to the third total reflector, and the exit surface of the adjusting reflector group is opposite to the reflecting surface of the antenna.

5. The quasi-optical system for terahertz waves of claim 4, wherein the set of adjustment mirrors comprises:

the fourth total reflecting mirror is arranged opposite to the third total reflecting mirror;

the fifth total reflector is arranged opposite to the fourth total reflector;

183GHZ electromagnetic waves and 325GHZ electromagnetic waves which are synthesized to one optical path by the third total reflecting mirror are adjusted by the fourth total reflecting mirror and the fifth total reflecting mirror and then irradiated to the antenna reflecting surface.

6. The quasi-optical system for terahertz waves according to claim 1, wherein the first total reflecting mirror, the second total reflecting mirror and the third total reflecting mirror are all ellipsoidal total reflecting mirrors.

7. The quasi-optical system for terahertz waves of claim 1, wherein the 183GHZ feed and the 325GHZ feed employ a corrugated horn feed.

8. The collimating optical system for terahertz waves according to claim 5, wherein the fourth total reflecting mirror is an ellipsoidal total reflecting mirror and the fifth total reflecting mirror is a parabolic total reflecting mirror.