Printed Circuit Board (PCB) is also known as Printed Wiring Board (PWB). It is used as the basis of circuit design in electronics and electrical engineering. It acts as a foundation, eliminating the need for redundant wiring and making any circuit cleaner. Removing excess wires makes the circuit more manageable and reduces weight. It is engraved with patterns and patterns that highlight the components connected to it, as well as patterns and traces that distinguish each PCB.

These traces act like wires, highlighting the access points and connections of different components placed on the PCB. Soldering is used to connect different components, which not only provides electrical connections to other devices connected, but also physically protects them. Let’s analyze one type of it: radar PCB, to understand what it is best suited for.

What is a radar PCBs?

Radar PCBs are described as PCB substrates designed for radars. These PCBs are essential for communication circuits and detection. Radar PCBs use high-frequency PCB materials. Since they are used for communication and detection circuits, radar PCBs need to be highly efficient and operate at higher frequency outputs than standard PCBs. They are designed to send and receive radio frequency signals.

The radar PCB contains an RF circuit that generates the radar lobe on its base, which is made of high-frequency laminate material, and an antenna is mounted on the base for transmission and reception. Modern radar PCBs also have digital circuits. This circuit analyzes the echoes encountered when transmitting and receiving, and its optimal location is on the back of the PCB.

Basic Components that Make Up a Radar PCB

Any PCB contains some components necessary to perform its main tasks. For a radar PCB, these are some of the components.

Transmitter: A radar cannot operate with the weak signal of a waveform generator. Therefore, the function of the transmitter is to use a power amplifier to boost the signal.
Receiver: The receiver uses a receiver processor (such as a superheterodyne) to find and analyze the reflected signal.
Antenna: A phased array, planar array, or parabolic reflector is responsible for transmitting and receiving pulses.
Duplexer: A duplexer is an electronic device that enables two-way (duplex) communication over a single path. It separates the receiver from the transmitter in radar and radio communication systems so that they can share an antenna. Antennas can be used as both transmitters and receivers and are equipped with a duplexer.

Waveguides: Data is transmitted through transmission lines in any mode. When information is transmitted in the form of waves, these transmission lines are also called waveguides. In radar PCBs, these waveguides are used as transmission lines for the path of transmitting and receiving signals.
Threshold Determination: When designing a circuit for any signal receiver, there will be a circuit for detecting noise. In music, noise refers to sounds below a certain frequency, which is considered pollution. This component compares the output of the receiver with a threshold to assess whether an object is present. After comparison, if the work is below that point, it can be inferred that noise is present.
Key Features of Radar PCBs
The quality of radar PCBs is defined with the following qualities as reference points:

PCB Range
The antenna in the radar sends a signal to the target at the speed of light. This signal is reflected into the antenna after colliding with the object. The distance between the object and the radar determines the range. Generally, a wide range is preferred because it can hit targets at a distance. For circuits, having a wider range is always preferred. This provides a wider basis for research because data can be transmitted and received from a greater distance. This allows fewer sensors to be installed when mapping a specific area.

Pulse Repetition Frequency
The transmission of a radar signal should occur every clock cycle if there is a reasonable delay between the clock cycles. Ideally, the device should only send out the next pulse after receiving an echo of the signal. Like a clock radio, the radar PCB sends a periodic signal via a wave of small rectangular pulses. The pulse repetition time is defined as the interval between two clock pulses.

Given this, the relationship between the pulse repetition frequency and the pulse repetition time is inversely proportional. It specifies how often the radar PCB transmits the signal. To improve the quality of the signal and received data, the more frequently the data is transmitted, the greater the depth of the received data.

Maximum Clear Range
The maximum distance at which a radar can see a target to ensure that the signal or pulse reflected from that target matches the most recently transmitted pulse. The time difference between the transmission and reception of a pulse calculates the radar range.

It is common to think of a received pulse as being connected to the most recently transmitted pulse because a received pulse will match the previous transmitted pulse and targets that are further away than the specified range will appear closer.

By encoding the pulses to distinguish between the most recently transmitted pulse and the older pulses, this problem can be avoided and ranges beyond the “clear range” can be measured. The echo of the signal is necessary to map (detect) any object, and if the echo is received alternately between the transmitted signals, there is a risk of critical data being lost.

Minimum Detection Range of Radar PCB
The minimum range of a radar PCB is defined as the situation where the echo of the transmitted wave is received before the full signal propagates. This indicates the minimum range of the signal by mapping the distance between the object and the receiver.

The minimum range of any radar PCB is crucial because it helps define the data that is not needed when it is used. The minimum range is crucial for positioning the sensor throughout the area to be mapped, and more importantly, where to avoid placing these PCBs.

Different Types of Radar PCBs
Radar technology is constantly improving. Therefore, there is no single technology for radar PCBs either. There are five types of radar PCBs. These five types are:

Doppler Radar PCB
As the name suggests, this type uses the Doppler effect to calculate the data velocity of an object at a certain distance away. When an object is closer to a stationary observer than it is closer to the source, it experiences higher frequency waves. However, when an object is farther from the observer, the wavelength of its waves is shorter than the source.

The Doppler effect is the name given to this frequency shift phenomenon. It transmits an electromagnetic signal to a target and then determines how the target affects the frequency of the echo. The radar PCB can be used as a reference for measurement and adjustment to determine the speed of an object.

Monopulse radar PCB is a type of radar that provides precise directional information by using an additional radio signal encoding. The term refers to the device’s ability to distinguish between distance and direction in a single signal pulse.

Monopulse radar avoids the troubles of conical scanning radar systems caused by sudden changes in signal strength. In addition, the system makes interference more challenging. Since the 1960s, most radars have been monopulse systems.

In addition, passive systems such as radio astronomy and power support systems also use monopulse technology. Monopulse radar systems can be built with reflectors, lenses, or array antennas.

Monopulse radar PCB compares the received signal using a specific pulse by comparing the characteristics of the signal with previously detected signals. Conical scanning radar PCB circuit is the most popular one. It compares the results of the two techniques to directly measure the position of an object.

Passive Radar PCB
A passive radar PCB system is a class of radar systems that detect and track objects by processing reflections from non-cooperative ambient lighting sources, such as commercial broadcast and communication signals. Passive radar systems are also known as passive coherent positioning, passive surveillance systems, and passive covert radars.

It is a special instance of bistatic radar that uses both cooperative and non-cooperative radar transmitters. A passive radar PCB is a detection device. It processes ambient lighting information, and once that mission is over, they assist in tracking the target.

Weather Radar PCB
Weather radar PCBs use radio frequency signals to assist with wind and weather detection, which is critical in today’s society. However, there is a trade-off between attenuation and reflections from precipitation due to atmospheric humidity. Similarly, you can use dual-polarized weather radars to identify precipitation types and use Doppler shifts to detect wind speeds.

Pulse Radar PCB
Finally, this PCB type transmits a high-frequency, high-intensity pulse to a target and then waits for the bounce signal to be transmitted. Doppler shift technology determines the range and resolution of the radar PCB by repeating the frequency of the transmission. Using the echo signal, this method can detect moving objects as shown below:

The signals from the static objects are in phase and cancel out when reflected.
When there is a phase difference in the pulses sent by the moving object.

Radar PCBs are an integral part of this world. The military and airports use them for air traffic control, remote sensing, and ground transportation. They also have space applications.