After Lin Yuanzhi left, Xu Jianguo took the initiative to greet Liu Wei and Qi Ying, saying, "Comrade Liu Wei, Comrade Qi Ying, hello. It's a pleasure to work with you!"
"You're welcome. Come on, I'll give you the information and then introduce our research plan to you." Liu Wei said, and without waiting for Xu Jianguo to answer, he turned and walked forward.
Qi Ying stuck out her tongue and followed.
Xu Jianguo was a little confused. He felt that the two men had some hostility towards him, but he didn't know where the hostility came from. However, he didn't care and just followed them.
The three of them arrived at an office. Liu Wei walked over to a filing cabinet, pulled out two stacks of documents, and placed them on the table. He said, "This is the research plan that the professor and other professors agreed on earlier. This is our conception of the radar receiver. Take a look at it first, and come back to me if you have any questions!"
"Okay, thank you!" Xu Jianguo said, then took the two documents on the table and sat aside to read them.
Liu Wei felt uncomfortable seeing Xu Jianguo's cold attitude towards him, so he asked, "Comrade Xu Jianguo, rote learning is useless. Although the teacher said that the materials we are using now were translated by you, I don't believe it psychologically. I wonder if you agree with what I said?"
"What do you want to express?" Xu Jianguo looked up at Liu Wei and asked.
"What I want to say is that you have to be down-to-earth in doing things. Don't think that you are really a major just because you put on a major's uniform. Don't think that it is so great to get in through the back door. There is no such thing as taking shortcuts here!" Liu Wei said, his eyes full of disdain.
"Are you done?" Xu Jianguo asked expressionlessly.
"Why, you have nothing to say?"
Xu Jianguo smiled and said, "It's not that I have nothing to say, I just think your narrow-minded attitude is ridiculous."
"You say I'm a frog in a well? But I..." Liu Wei said angrily.
"Who you are and where you come from has nothing to do with me, and I don't need your approval. Put away your self-righteousness!" Xu Jianguo said.
"You can't say that about my senior brother. He said that for your own good!" Qi Ying also said from the side.
"Don't always impose your will on others under the guise of doing good for them. That's bandit logic!"
"You...you are unreasonable!" Qi Ying was speechless after being confronted by Xu Jianguo, and could only stomp her feet and retort.
"Xu Jianguo, if you think I'm wrong, then you can provide evidence to prove yourself. It's useless to make specious excuses!" Liu Wei continued.
"Oh? How do you need me to prove it?"
"You...the teacher said that you translated the information and that you are very good at mechanical engineering and electromagnetic waves. Then tell me what is Doppler radar? What is a receiver? If you can't tell me, I will definitely go to the teacher and expose you!" Liu Wei said.
"What if I tell it?"
"Then I'll apologize to you!"
Xu Jianguo showed a mocking expression on his face and said, "Haha, your apology is useless to me. Don't take yourself too seriously. I just proved myself because I don't want you two to nag me like flies in the future. Even if you don't bother me, I still do. Listen carefully!"
Doppler radar, also known as pulse Doppler radar, is a type of radar that uses the Doppler effect to detect the position and relative velocity of moving targets. In 1842, Austrian physicist J.C. Doppler discovered that when a wave source and an observer are in relative motion, the frequency of the wave received by the observer differs from the frequency transmitted by the source. This phenomenon is known as the Doppler effect. As the source and observer approach each other, the received frequency increases; as they move away, it decreases. Doppler radar is a type of pulse radar that utilizes this Doppler effect. Pulse Doppler radars contain range gate circuits, single-sideband filters, main-beam clutter suppression circuits, and detection filter banks, effectively suppressing interference from ground objects. Pulse Doppler radars are used in airborne early warning, airborne interception, airborne navigation, low-altitude defense, fire control, battlefield reconnaissance, missile guidance, range measurement, satellite tracking, and weather detection.
Its working principle is that when a radar transmits a pulse wave of a fixed frequency to scan the sky, if it encounters a moving target, the frequency of the echo and the frequency of the transmitted wave will have a frequency difference, which is called the Doppler frequency. Based on the size of the Doppler frequency, the radial relative motion speed of the target with respect to the radar can be measured; based on the time difference between the transmitted pulse and the received pulse, the distance to the target can be measured. At the same time, the frequency filtering method is used to detect the Doppler frequency spectrum of the target and filter out the spectrum lines of interfering clutter, which enables the radar to distinguish the target signal from the strong clutter. Therefore, Doppler radar has a stronger ability to resist clutter interference than ordinary radar and can detect moving targets hidden in the background. "Xu Jianguo's voice was not loud, but every word exploded in the ears of Liu Wei and Qi Ying like a bell, shocking their minds into a blank.
Before the two could react, Xu Jianguo continued, "The radar receiver is a crucial component of the radar system. Its primary function is to preselect, amplify, frequency-convert, filter, demodulate, and digitize the weak signals received by the radar antenna. It also suppresses external interference and internal noise, ensuring that the echo signal retains as much target information as possible for further signal and data processing. The main components of the receiver front end include the receiver protector, RF amplifier, RF filter, and mixer."
After Xu Jianguo finished speaking, he looked at the two of them and asked, "Any more questions?"
"You...how do you know all this?" Liu Wei asked with his eyes wide open and an incredible look on his face.
"How I know this has nothing to do with you. Do you admit that you are a frog in a well?" Xu Jianguo said.
"you……"
"Don't be so abusive. Isn't it time for you to apologize to me?"
Liu Wei stood there with his face flushed and his head lowered, not saying a word.
Xu Jianguo shook his head and continued, "It seems that you are not going to apologize to me. Okay, then I will tell you one more thing!" After that, he stood up from the chair, took out his military officer's certificate from his jacket pocket, walked to Liu Wei, opened the certificate and placed it in front of him.
When Liu Wei saw the photo and content on the officer's ID card, his face turned extremely pale.
Xu Jianguo put away his military officer certificate, picked up the two documents on the table, turned around and left the office.
Continue read on readnovelmtl.com