Millimeter wave radar concept
The so-called millimeter wave is a section of the radio wave. We call the electromagnetic wave with a wavelength of 1-10 mm millimeter wave, which is located in the wavelength range where microwave and far-infrared wave intersect, so it has the characteristics of two kinds of the wave spectrum. The theory and technology of millimeter wave radar are respectively the extensions of microwave to high frequency and the development of light wave to low frequency.
The so-called millimeter wave radar refers to the radar whose working frequency is in the millimeter wave frequency band. The ranging principle is the same as that of ordinary radar, that is, it sends out radio waves (radar waves), receives echoes, and measures the position data of the target according to the time difference between receiving and transmitting. Millimeter wave radar is the radio wave whose frequency is in the millimeter wave band.
Characteristics of Millimeter wave radar
1. In the case of the same antenna aperture, millimeter wave radar has a narrower beam (generally in the order of milliradian), which can improve the angle resolution and angle measurement accuracy of the radar, and is conducive to anti-electronic interference, clutter interference, and multipath reflection interference.
2. Due to the high working frequency, a large signal bandwidth (such as Gigahertz magnitude) and Doppler frequency shift may be obtained, which is conducive to improving the measurement accuracy and resolution of range and speed and analyzing target characteristics.
3. The antenna aperture, components, and devices are small and suitable for aircraft, satellites, or missiles.
Advantages and disadvantages of Millimeter wave radar
Compared with other sensor systems, millimeter wave radar has the following advantages:
(1) High resolution and small size. The smaller size of the antenna and other microwave components allows for a smaller antenna size and the ability to obtain a narrow beam.
(2) Although interference and atmospheric attenuation limit the performance of millimeter wave radar, they also reduce mutual influence when multiple radars work together.
(3) Compared with the infrared system, which is often used for comparison, millimeter wave radar has the advantage of directly measuring range and speed information.
Disadvantages:
(1) The performance of millimeter wave radar has declined compared to microwave radar due to low power of the transmitter and high loss in waveguide devices.
(2) It is heavily impacted by weather, especially during rain.
(3) In the air defense environment, distance ambiguity and velocity ambiguity are inevitable.
(4) Millimeter wave devices are expensive and cannot be mass produced.
Millimeter wave radar speed measurement mode
Like ordinary radar, millimeter wave radar has two ways to measure velocity. One is based on the principle of doppler, which measures the relative movement between the transmitted electromagnetic wave and the detected target. However, this method cannot detect tangential velocity. The second method involves obtaining the velocity by tracking the position and differential.
The operating principle of millimeter wave radar
The millimeter wave velocity measuring radar system is mainly composed of a tuner, a preprocessing system, a terminal system, and an infrared starter.
Millimeter wave radar oscillator generates millimeter wave (8mm) oscillation with a frequency set as f0. This wave is then directed from the antenna and propagates as an electromagnetic wave in space. When the wave encounters a moving target, the reflected electromagnetic wave frequency is added with a Doppler frequency (fd) proportional to the target’s speed (vr). The reversed echo frequency becomes f0 ± fd depending on the target’s distance. This echo is received by the antenna, added to the mixer through the circulator, and then mixed with the signal leaked through the circulator (as the local oscillator signal) f0 in the mixer. The Doppler signal (frequency fd) is then selected by the preamplifier and sent to the main amplifier of the preprocessing system through a long cable (length 50-100m). The main amplifier is equipped with automatic gain control and manual gain control circuits.
Generally, automatic gain control is not used in interior ballistic tests, and is only suitable for testing external ballistics. This is to avoid the interference of muzzle flame before starting the test after an appropriate delay.
The so-called millimeter wave is a section of the radio wave. We call the electromagnetic wave with a wavelength of 1-10 mm millimeter wave, which is located in the wavelength range where microwave and far-infrared wave intersect, so it has the characteristics of two kinds of the wave spectrum. The theory and technology of millimeter wave radar are respectively the extensions of microwave to high frequency and the development of light wave to low frequency.
The so-called millimeter wave radar refers to the radar whose working frequency is in the millimeter wave frequency band. The ranging principle is the same as that of ordinary radar, that is, it sends out radio waves (radar waves), receives echoes, and measures the position data of the target according to the time difference between receiving and transmitting. Millimeter wave radar is the radio wave whose frequency is in the millimeter wave band.
Characteristics of Millimeter wave radar
1. In the case of the same antenna aperture, millimeter wave radar has a narrower beam (generally in the order of milliradian), which can improve the angle resolution and angle measurement accuracy of the radar, and is conducive to anti-electronic interference, clutter interference, and multipath reflection interference.
2. Due to the high working frequency, a large signal bandwidth (such as Gigahertz magnitude) and Doppler frequency shift may be obtained, which is conducive to improving the measurement accuracy and resolution of range and speed and analyzing target characteristics.
3. The antenna aperture, components, and devices are small and suitable for aircraft, satellites, or missiles.
Advantages and disadvantages of Millimeter wave radar
Compared with other sensor systems, millimeter wave radar has the following advantages:
(1) High resolution and small size. The smaller size of the antenna and other microwave components allows for a smaller antenna size and the ability to obtain a narrow beam.
(2) Although interference and atmospheric attenuation limit the performance of millimeter wave radar, they also reduce mutual influence when multiple radars work together.
(3) Compared with the infrared system, which is often used for comparison, millimeter wave radar has the advantage of directly measuring range and speed information.
Disadvantages:
(1) The performance of millimeter wave radar has declined compared to microwave radar due to low power of the transmitter and high loss in waveguide devices.
(2) It is heavily impacted by weather, especially during rain.
(3) In the air defense environment, distance ambiguity and velocity ambiguity are inevitable.
(4) Millimeter wave devices are expensive and cannot be mass produced.
Millimeter wave radar speed measurement mode
Like ordinary radar, millimeter wave radar has two ways to measure velocity. One is based on the principle of doppler, which measures the relative movement between the transmitted electromagnetic wave and the detected target. However, this method cannot detect tangential velocity. The second method involves obtaining the velocity by tracking the position and differential.
The operating principle of millimeter wave radar
The millimeter wave velocity measuring radar system is mainly composed of a tuner, a preprocessing system, a terminal system, and an infrared starter.
Millimeter wave radar oscillator generates millimeter wave (8mm) oscillation with a frequency set as f0. This wave is then directed from the antenna and propagates as an electromagnetic wave in space. When the wave encounters a moving target, the reflected electromagnetic wave frequency is added with a Doppler frequency (fd) proportional to the target’s speed (vr). The reversed echo frequency becomes f0 ± fd depending on the target’s distance. This echo is received by the antenna, added to the mixer through the circulator, and then mixed with the signal leaked through the circulator (as the local oscillator signal) f0 in the mixer. The Doppler signal (frequency fd) is then selected by the preamplifier and sent to the main amplifier of the preprocessing system through a long cable (length 50-100m). The main amplifier is equipped with automatic gain control and manual gain control circuits.
Generally, automatic gain control is not used in interior ballistic tests, and is only suitable for testing external ballistics. This is to avoid the interference of muzzle flame before starting the test after an appropriate delay.
