60G mmWave Radar
2022-04-24 284

Advantages and Challenges of Using 60GHz Frequency
From an engineering point of view, the application of 60 GHz frequency in radar systems still presents some challenges.
A big challenge is that it becomes difficult to track objects at the edges of the field of view (FOV), because the reflected signal strength is stronger the closer to the center of the FOV, so the reflected signal strength is weakest at the edges. This is a well-known situation, but can be compensated by using multiple radar system sensors.
Another challenge involves the algorithms that radar systems use to determine which are tracked targets and which are background interference. Like a stationary object in a cluttered background environment (eg, several people sitting at a table for an extended period of time), traditional Doppler domain processing sometimes incorrectly classifies stationary objects as background distractors.
The potential benefits of radar systems designed at 60 GHz may far outweigh these challenges.
There are some potential benefits to developing applications at the 60GHz frequency. The first one is not related to factors inherent in the frequency itself, but due to the fact that other radio frequencies are congested successfully: for example the frequencies of Wi-Fi are the lower 2.4GHz and 5GHz, due to the high congestion on these frequencies, Wi-Fi networks suffer from increasing performance issues. The 60GHz frequency does not have the trouble of congestion at present, so it can guarantee better signal integrity.
A related benefit is that the unlicensed 60GHz frequencies offer up to 9GHz of spectrum - many times more bandwidth than those unlicensed lower frequencies offer. This also supports the claim that the 60GHz frequency guarantees better signal integrity.
In the past ten years, people's attention and research on 60GHz has mainly focused on wireless communication. However, for areas such as radar systems, the large bandwidth of the 60GHz frequency can provide more accurate radar readings, extending radar uses to people counting, building automation, workplace and perimeter security, etc. that have not been widely implemented before. application.
Another benefit of the 60GHz frequency comes from its shorter wavelength. The short wavelengths of the 60GHz frequency are unlikely to pass through walls and buildings (2.4GHz Wi-Fi signals do). This used to be seen as a drawback, as we used to look at frequencies primarily through the lens of communication systems, so we sought out radio signals that could travel through walls and buildings (eg, cellular and Wi-Fi networks). In many cases we do desire signals that can pass through walls, however, with the proliferation of radio signals such as broadcast television, wireless communications, etc., the need to keep the signal in a specific space continues to increase.
There are several factors that affect whether a signal can penetrate solid objects (such as the walls of a building), some of which are related to the wavelength of the signal. Whether a wireless signal can penetrate a physical barrier such as a building wall depends largely on the material of the wall. As long as the walls are not made of highly conductive metals or extremely dense materials (bricks, concrete, etc.), Wi-Fi signals usually have no problems propagating from one room of the home to another.
The most common RF and microwave signals - such as AM/FM radio signals, TV signals, cellular signals and Wi-Fi signals - outline some relatively longer wavelengths in descending order from wavelengths of a few meters to the 12mm wavelength used by Wi-Fi signals Applications. For signals with these wavelength levels, normal building walls are effectively "transparent" and they pass through the walls as easily as light passes through glass. However, at higher signal frequencies, the wall becomes less like a glass window that lets light through, and more like a closed door.