Ka waveband optical phase equalization system and running method thereof

Abstract

The invention discloses a Ka waveband optical phase equalization system and a running method thereof. A light source, an electro-optical modulation unit, an adjustable delay unit and a photoelectric demodulation unit of the system form an optical link, and output a Ka microwave signal of equalized phase. The electro-optical modulation unit is a quadrature bias MZM modulator, the photoelectric demodulation unit is a PIN photoelectric detector, the adjustable delay unit is an optical delay module with a tuning stepping motor, a microcontroller is connected with a bias control unit and a tuning control unit and respectively controls a bias voltage of the MZM modulator and a revolving speed and a position of the tuning stepping motor, and the microcontroller is connected with an upper computer through a CAN bus. The running method is that power-on self test is carried out, and the microcontroller controls the adjustable delay unit according to a command of the upper computer to realize phase delay; and periodical self test is carried out for guaranteeing output to be normal. Optical delay is expanded to a Ka waveband, delay accuracy is up to 0.1 picosecond, and the optical delay is highly accurate, continuous and adjustable; a single host computer can perform remote control for a plurality of devices, and thus, the system is small in volume, low in power consumption, light in weight and easy to operate.

Description

Technical field [0001] The invention relates to optical communication technology, in particular to a Ka-band optical phase equalization system and an operating method thereof. Background technique [0002] In the past ten years or so, the number of microwave communication users has increased dramatically, making the microwave spectrum crowded. In addition, the development requirements of precision weapon systems have prompted people to extend the operating frequency of the system upwards. For example, the operating frequency of the phased array radar system has been increased to the Ka band (frequency 26.5~40GHz) or even W band (frequency 75~110GHz) . [0003] In a multi-channel microwave communication system, due to the non-ideality of each physical channel, the phase of the microwave signal after transmission is inconsistent. Therefore, it is usually necessary to equalize the phase of the microwave signal in each channel. The optical delay line has small size and weight. It has...

AI Technical Summary

Problems solved by technology

First of all, the currently commonly used optical delay line is incrementally adjustable rather than continuously adjustable. Although the incrementally adjustable delay line can achieve a large delay dynamic range, its accuracy can only reach the order of tens of picoseconds, which is extremely large. Secondly, the operating frequency band of the radar system is gradually increased to the Ka band or even the W band, while the modulation frequency of the existing optical delay line signal is generally below the Ku band (12-18 GHz), which is difficult to meet advanced Requirements for the use of radar systems

In addition, in order to ensure that the optical delay line can stably transmit broadband microwave signals, it is necessary to bias the Mach-Zehnder modulator (MZM) at the quadrature bias point, but the thermal effect will cause the transfer function of the MZM to shift over time

[0004] In the part of communication interface, the control interface of existing optical delay line equipment is mostly RS232 serial communication, which is difficult to realize the point-to-multiple control requirements of the control center

Although a small number of optical delay line devices use the RS422 / 485 serial bus as the communication method, and can also realize the single-master and multiple-slave control method, the reliability of this communication link is low, and there is no effective error handling mechanism. If a node fails, it will easily lead to the paralysis of the entire control network, that is, there is a risk of single point failure

For the application of phased array radar system, the conditions of electromagnetic interference and environmental stress are relatively harsh, and the number of nodes is large, so the existing optical delay line equipment is difficult to meet the requirements

Images