CN207730935U - A kind of radar system - Google Patents

Abstract

The utility model relates to the field of radar, in particular to a radar system. The radar system includes: the optical signal transmitter emits a 1550nm optical signal; the optical signal receiver includes a focusing lens, and also includes an avalanche diode or an avalanche diode array, The 1550nm optical signal is transmitted to the detected object in front and reflected back to the optical signal receiver, and enters the avalanche diode or avalanche diode array through the focusing lens, and the avalanche diode or avalanche diode array converts the received 1550nm optical signal It is an electrical signal; the controller is respectively connected with the optical signal transmitter and the optical signal receiver to control the operation of the optical signal transmitter and collect the electrical signal. It emits 1550nm optical signal, the repetition frequency of 1550nm laser can reach megahertz, and has a high water absorption coefficient. When the laser in this band irradiates the human eye, the damage threshold to the human eye is high, which improves the safety performance of the radar.

Description

a radar system

technical field

The invention relates to the field of radar, in particular to a radar system.

Background technique

Lidar is a radar system that emits laser beams to detect characteristic quantities such as the position and speed of targets. Its working principle is to send a detection signal (laser beam) to the target, and then compare the received signal (target echo) reflected from the target with the transmitted signal, and after proper processing, the relevant information of the target can be obtained, such as Target distance, azimuth, height, speed, attitude, and even shape parameters, so as to detect, track and identify aircraft, missiles and other targets. It consists of a laser transmitter, an optical receiver, a turntable and an information processing system. The laser converts electrical pulses into optical pulses and emits them. The optical receiver then restores the optical pulses reflected from the target into electrical pulses and sends them to the display.

At present, most lidar light sources use semiconductor lasers with a wavelength of 905nm, but their frequency is low and the safety threshold of human eyes is low. When scanning, the light source adopts an asynchronous working mode, and the effective distance of detection is limited.

Contents of the invention

The technical problem to be solved by the present invention is to provide a radar system for the above-mentioned defects of the prior art, which solves the problem that most laser radar light sources use semiconductor lasers with a wavelength of 905nm, but their frequency is low and the safety threshold of human eyes is low. Using a non-synchronous working method, the effective detection distance is limited.

The technical solution adopted by the present invention to solve the technical problem is: provide a radar system, an optical signal transmitter, and the optical signal transmitter emits a 1550 nanometer optical signal;

Optical signal receiver, the optical signal receiver includes a focusing lens, and also includes an avalanche diode or avalanche diode array, the 1550 nanometer optical signal is transmitted to the detected object in front and reflected back to the optical signal receiver, and is incident to the optical signal receiver through the focusing lens In the avalanche diode or the avalanche diode array, the avalanche diode or the avalanche diode array converts the received 1550 nanometer optical signal into an electrical signal;

A controller, the controller is respectively connected with the optical signal transmitter and the optical signal receiver, controls the operation of the optical signal transmitter, and collects electrical signals.

Among them, the preferred solution is: the optical signal transmitter includes a seed source, an optical fiber amplifier and a collimating lens arranged in sequence; the seed source emits a 1550 nanometer optical signal, the optical fiber amplifier amplifies the optical signal, and the collimating lens will The optical signal is collimated and transmitted to the detected object in front.

Among them, the preferred solution is: the seed source, the optical fiber amplifier and the collimating lens are connected through an optical fiber; the seed source emits a 1550 nanometer optical signal and is transmitted to the optical fiber amplifier through an optical fiber, and then transmitted to the collimating lens through an optical fiber middle.

Among them, a preferred solution is: the 1550nm optical signal is a continuous waveform or a pulse waveform.

Among them, the preferred solution is: the optical fiber amplifier uses rare earth elements doped.

Among them, the preferred solution is: the optical signal transmitter is a fiber laser, and the fiber laser emits a laser signal of 1550 nanometers.

Among them, a preferred solution is: the focusing lens is connected to the avalanche diode or the avalanche diode array through an optical fiber; the reflected light received by the focusing lens is transmitted to the avalanche diode or the avalanche diode array through the optical fiber.

The beneficial effect of the present invention is that, compared with the prior art, the present invention transmits a 1550nm optical signal by designing a radar system, the repetition frequency of the 1550nm laser can reach megahertz, and has a higher water absorption coefficient, when When the laser in this band irradiates the human eye, the damage threshold to the human eye is higher, which improves the safety performance of the radar.

Description of drawings

The present invention will be further described below in conjunction with accompanying drawing and embodiment, in the accompanying drawing:

Fig. 1 is the structural representation of radar system of the present invention;

Fig. 2 is the concrete structural representation of radar system of the present invention;

Fig. 3 is a schematic structural view of a seed source optical signal transmitter of the present invention;

Fig. 4 is a schematic structural diagram of the fiber laser of the present invention.

Detailed ways

Now in conjunction with the accompanying drawings, the preferred embodiments of the present invention will be described in detail.

As shown in Figures 1 and 2, the present invention provides a preferred embodiment of a radar system.

A radar system, including an optical signal transmitter, an optical signal receiver and a controller, specifically: the optical signal transmitter emits a 1550 nanometer optical signal; the optical signal receiver includes a focusing lens, and also includes an avalanche diode or an avalanche diode Array, the 1550nm optical signal is transmitted to the detected object in front and reflected back to the optical signal receiver, and is incident into the avalanche diode or avalanche diode array through the focusing lens, and the 1550nm light received by the avalanche diode or avalanche diode array The signal is converted into an electrical signal; the controller is respectively connected with the optical signal transmitter and the optical signal receiver to control the operation of the optical signal transmitter and collect the electrical signal.

Furthermore, the optical signal receiver is only sensitive to light at 1550nm, and light in other wavelength bands can be judged as noise without identification. And, the controller is preferably an MCU, ie a microprocessor.

Among them, the avalanche diode is a solid-state microwave device that uses two physical effects of carrier ionization and transit time in the semiconductor structure to generate negative resistance, and converts the received 1550-nanometer optical signal into an electrical signal. The avalanche diode array arranges a plurality of avalanche diode arrays on a plane to increase the light receiving area and increase the light receiving amount.

Among them, the focusing lens belongs to the graded index lens, and has the characteristics of end face focusing and imaging, and has the characteristic of cylindrical shape.

In this embodiment, the focusing lens communicates with the avalanche diode or the avalanche diode array through an optical fiber; the reflected light received by the focusing lens is transmitted to the avalanche diode or the avalanche diode array through the optical fiber.

In this embodiment, the 1550nm optical signal is a continuous waveform or a pulse waveform.

Among them, the output power of the continuous waveform is limited, and the peak power of the pulse waveform is high.

As shown in FIG. 3 , the present invention provides a preferred embodiment of an optical signal transmitter.

The optical signal transmitter includes a seed source, an optical fiber amplifier and a collimating lens arranged in sequence; the seed source emits a 1550nm optical signal, the optical fiber amplifier amplifies the optical signal, and the collimating lens collimates the divergent optical signal, And transmit to the detected object in front.

Among them, the seed source generates a 1550 nm optical signal after activation.

Among them, the Optical Fiber Amplifier (OFA for short) refers to a new type of all-optical amplifier used in optical fiber communication lines to achieve signal amplification. Compared with the traditional semiconductor laser amplifier (SOA), OFA does not need to go through complex processes such as photoelectric conversion, electro-optical conversion and signal regeneration, and can directly amplify the signal all-optical, with good "transparency".

Further, the seed source, the fiber amplifier and the collimating lens are connected through an optical fiber; the seed source emits a 1550nm optical signal and transmits it to the fiber amplifier through the fiber, and then transmits it to the collimating lens through the fiber.

Among them, the optical fiber amplifier uses doped rare earth elements. Rare earth elements can achieve 1550nm signal light amplification under the action of pump laser.

As shown in Fig. 4, the present invention provides a preferred embodiment of an optical signal transmitter.

The optical signal transmitter is a fiber laser, and the fiber laser emits a laser signal of 1550 nanometers. The above are only the best embodiments of the present invention, and are not used to limit the scope of the present invention. All equivalent changes or modifications made according to the patent scope of the present invention are covered by the present invention.

Claims (7)

1. a kind of radar system, which is characterized in that the radar system includes：

Optical signal transmitter, the optical signal transmitter emit 1550 nanometers of optical signals；

Optical signal receiver, the optical signal receiver include condenser lens, and further include avalanche diode or avalanche diode Array, the detected object and reflected light signal receiver of 1550 nanometers of optical signal launch to front, through over-focusing Mirror is incident in avalanche diode or avalanche photodiode arrays, and the avalanche diode or avalanche photodiode arrays are by reception 1550 nanometers of optical signals are converted into electric signal；

Controller, the controller are connect with optical signal transmitter and optical signal receiver respectively, control optical signal transmitter work, And acquisition electric signal.

2. radar system according to claim 1, it is characterised in that：The optical signal transmitter includes the seed set gradually Source, fiber amplifier and collimation lens；The seed source emits 1550 nanometers of optical signals, which puts optical signal Greatly, which collimates the optical signal of diverging, is concurrently incident upon the detected object in front.

3. radar system according to claim 2, it is characterised in that：The seed source, fiber amplifier and collimation lens Between be connected to by optical fiber；The seed source emits 1550 nanometers of optical signals and is transferred to fiber amplifier by optical fiber, and It is transferred in collimation lens by optical fiber again.

4. radar system according to claim 2, it is characterised in that：1550 nanometers of optical signals are continuous wave or arteries and veins Rush waveform.

5. radar system according to claim 2, it is characterised in that：The fiber amplifier uses doped rare earth element.

6. radar system according to claim 1, it is characterised in that：The optical signal transmitter is optical fiber laser, the light Fibre laser emits 1550 nanometers of laser signal.

7. radar system according to claim 1, it is characterised in that：The condenser lens and avalanche diode or snowslide two It is connected to by optical fiber between pole pipe array；The reflected light that the condenser lens receives is transferred to avalanche diode or snow by optical fiber Collapse diode array.