PCB Blog - Advantages of PCB weather radar

A weather radar is a type of weather radar that is the main tool for monitoring and warning of severe convective weather. The working principle of PCB weather radar is to emit a series of pulse electromagnetic waves, utilizing the scattering and absorption of electromagnetic waves by precipitation particles such as clouds, rain, and snow, to detect the spatial distribution and vertical structure of precipitation, and use it as a warning and tracking precipitation system.

Weather radars are mostly pulsed, transmitting pulses of very short duration at a certain repetition frequency and subsequently receiving echo signals scattered back by precipitation particles. By analysing and judging these precipitation echoes, we can determine a variety of macroscopic and microphysical properties of precipitation. Various theoretical and empirical formulas have been developed to describe the relationship between precipitation echo power and precipitation intensity, and using these relationships, we can measure the distribution of precipitation intensity as well as the total precipitation in the radar coverage area based on the echo power. Given the relatively weak signal reflections from clouds, rainfall and ice crystals, this sets a higher standard for radar reception performance.

Classification of Radar

Classification according to antenna scanning method

According to the scanning method of antenna, radar can be divided into two categories: mechanically scanned radar and phased array radar. At the beginning of the 21st century, China's radar industry is dominated by the mechanical scanning radar, which transmits signal waves centrally and uses the rotation of the mechanical rotary table to guide the signal waves to different directions to detect different targets. However, due to the inefficiency of its mechanical rotation, the detection range and targets are limited, and it has been difficult to adapt to the increasingly complex electromagnetic field development trend. In recent years, phased array technology has been increasingly used in the radar field. Unlike mechanically scanned radar, which realises radar beam steering by rotating the antenna, phased array radar adopts ‘electronic phase shifter’ to complete scanning. Therefore, the phased array radar in the response speed, update frequency, multi-target tracking ability and resolution, etc. have been significantly improved, become the main development direction of the current radar industry. Despite the excellent performance of phased array radar, its technical implementation is complex and costly, and has long been mainly used in the military field. The high price has become a key factor hindering its large-scale application in the civilian field.

According to the difference of waveband, radar can be mainly divided into S-band, C-band, X-band, etc. (or subdivided into over-the-horizon radar, microwave radar, millimetre-wave radar, and laser radar). Typically, radars with lower frequencies have a wider search range, but their accuracy decreases accordingly. Strict national regulations on the use of bands are in place to prevent civilian radars from interfering with military radars and communications systems.

Depending on the transmitter/receiver unit, radars can be divided into two types: active phased array radar (AESE) and passive phased array radar (PESE). The core difference between them is the T/R module (i.e., transmitter/receiver module). The antenna array of an active phased array radar consists of numerous transmitter/receiver modules, so its surface is covered with protruding T/R components, and each T/R module is equipped with both transmitter and receiver functions, so it is also called an active phased array radar. In contrast, passive phased array radar is only equipped with a central transmitter and receiver, all radiation units share this central T/R module, its antenna appearance is flat, the high-frequency energy generated by the transmitter is distributed to the various units of the antenna array through the power distribution network, and the signals reflected from the target are also collected by the various antenna units and then sent to the receiver to be unified and amplified, and thus it is also known as passive phased array radar.

Functionally, since each radiator of active phased array radar is equipped with a transmitter/receiver component that can generate and receive electromagnetic waves autonomously, its response speed, scanning range, multi-target tracking capability, reliability and anti-jamming capability are significantly better than those of previous radar systems. In addition, active phased array radar can form multiple independent beams at the same time to achieve multiple functions such as search, identification, tracking, guidance and passive detection. The passive phased array radar has only one central transmitter and receiver, and its high-frequency energy is automatically distributed to each radiator of the antenna array by the computer, and the signals reflected from the target need to be uniformly amplified by the receiver, so it is not as good as active phased array radar in terms of power, efficiency, beam control and reliability. However, passive phased array radar is relatively low in cost and technical difficulty.

PCB weather radar

The commonly used wavelengths for PCB weather radar are mostly in the range of 1-10cm. Because the attenuation of the 10cm wavelength is small, it is better to detect typhoons, rainstorms and hail. The commonly used domestically are domestically produced 713 mines (5.6cm), 714 radars (10cm), and 711 radars (3.2cm), which can detect weather systems within a range of several hundred kilometers around radar stations.

Advantages of PCB weather radar

1. PCB weather radar signals can penetrate materials such as clouds and rubber.

2. The PCB weather radar circuit can determine the speed, distance, and position of objects during movement.

3. The signals/pulses from PCB weather radar do not require media (wires) for transmission, as they can travel through space, water, and air.

4. PCB weather radar operates at high frequencies to save a large amount of data.

5. The signal from PCB weather radar can cover a large area without additional cost.

The basic components of PCB weather radar include:

1. Transmitter: The signal from the waveform generator is not strong enough for the radar. Therefore, the purpose of the transmitter is to amplify the signal using a power amplifier.

2. Receiver: The receiver uses a receiver processor (such as superheterodyne) to detect and process reflected signals.

Antenna: including parabolic reflector, planar array or electronically controlled phased array. It is responsible for sending and receiving pulses.

3. Duplexer: A duplexer is a device that enables an antenna to complete transmitter and receiver tasks. The working principle of a duplexer.

The working principle of PCB weather radar

PCB weather radar is an instrument used to detect weather phenomena such as precipitation, clouds, and storms in the atmosphere. Its basic working principle is to use radar beams to emit electromagnetic waves into the atmosphere. When these electromagnetic waves encounter substances such as water droplets and ice crystals in the atmosphere, they will undergo scattering and reflection. These reflected waves will be received by the receiver and converted into electrical signals. Through signal processing and analysis, information such as precipitation, clouds, storms, etc. in the atmosphere can be obtained.

The transmitter of PCB weather radar usually uses high-frequency electromagnetic waves with wavelengths ranging from 1 to 10 centimeters, which can penetrate clouds and precipitation without being absorbed or scattered. A radar transmitter emits electromagnetic waves into the atmosphere, which propagate in a certain direction to form a radar beam. When this radar beam encounters substances such as water droplets and ice crystals in the atmosphere, it undergoes scattering and reflection, which are received by the receiver and converted into electrical signals.

The receiver of PCB weather radar usually uses a highly sensitive receiver that can receive weak electrical signals. After receiving the reflected wave, the receiver converts it into an electrical signal and obtains information such as precipitation, clouds, storms, etc. in the atmosphere through signal processing and analysis. The process of signal processing and analysis includes steps such as filtering, denoising, demodulation, and demodulation. The final information obtained can be used to predict weather and formulate response measures.

The radar PCB can be described as an electronic circuit responsible for creating, transmitting, and receiving radio frequency signals. In addition, it also has an antenna structure installed in high-frequency laminated material, which transmits radar lobes generated by RF circuits.

In addition, the same antenna will receive reflected radar pulses once it hits a target and has been analyzed by the RF circuit. Usually, this modern radar circuit board will be equipped with digital circuits at the rear, which helps analyze any echoes, while the antenna and RF part is located at the front.

Key Elements of PCB Weather Radar

Range

The radar has an antenna that can transmit light-speed signals to the target. Once the target is hit, the signal will be reflected into the antenna. The distance between the object and the radar defines the distance.Usually, it is better to use a wider range because it allows users to reach distant goals.

Pulse repetition frequency

The transmission of radar signals must occur within all clock cycles, with appropriate delay intervals between these clock cycles. Ideally, the device should receive the echo of the signal before transmitting it to the next pulse. Similarly, the function of radar PCB is the same, sending periodic signals to form rectangular narrow pulse waves.

The delay between these two clock pulses will form the repetition time of the pulses. Considering this,the frequency of pulse repetition is the inverse of pulse repetition time. This helps to determine the time when the radar PCB sends the signal.

Clarify maximum distance

Each clock pulse needs to transmit a signal.Moreover,the echo of the current clock pulse can only be received when there is a short interval between the current clock pulse and the next clock pulse. However, you will find that the target's range is shorter than normal.That's why you must choose the delay between these intervals wisely.

Usually, you must receive the echo of the current clock pulse before the next clock pulse is emitted.In this way,the signal will provide you with a very clear image and a view of the actual range of the object, which is the clear maximum range.

Minimum range

Contrary to this range, this minimum coverage range is the time it takes for the echo to reach the antenna after the initial transmission of the pulse width.

PCB weather radar plays an irreplaceable role in disaster weather monitoring and warning.