BACKGROUND

Radars are useful devices that can detect and track objects, map surfaces, and display weather patterns. While radar is a common tool used in military and air traffic control operations, technological advances are making it possible to integrate radars in electronic devices. In many cases, a radar may replace bulky and expensive sensors, such as a camera, and provide improved performance in the presence of different environmental conditions, such as low lighting, motion, or overlapping targets. While it may be advantageous to use the radar, there are many challenges associated with using radar in commercial devices and commercial applications.

One such problem involves integrating and operating the radar in the presence of an attenuator. The attenuator may include an exterior housing of the electronic device or another external material that attenuates or distorts a radar signal. As available power may be limited in small and mobile radar systems, compensating for the attenuation by increasing the transmitted power may not be possible. As such, the attenuator degrades performance of the radar by decreasing an effective range, limiting the ability to detect smaller targets, and reducing tracking accuracy. Consequently, the effective operation and capability of the radar can be significantly reduced due to the attenuator, thereby frustrating users or limiting the types of applications or environments the radar can support.

SUMMARY

Techniques and apparatuses are described that enable radar attenuation mitigation. To improve radar performance, characteristics of an attenuator and/or properties of a radar signal are determined to reduce attenuation of the radar signal due to the attenuator and enable the radar system to detect a target located on an opposite side of the attenuator. These techniques are beneficial in situations in which the attenuator is unavoidably located between the radar system and a target, either due to integration within other electronic devices or due to an operating environment. These techniques save power and cost by reducing the attenuation without increasing transmit power or changing material properties of the attenuator.

Aspects described below include an apparatus comprising a radar system and an attenuator. The radar system operates within a frequency range and a range of steering angles. The radar system transmits a radar signal using a frequency of the frequency range and a steering angle of the range of steering angles to detect a target. The attenuator is located between the radar system and the target. The attenuator has a semi-transparent material that attenuates the radar signal. The attenuator is located at a distance from the radar system and has a non-zero thickness. The distance is a best distance within the range of distances and the non-zero thickness is a best thickness within the range of thicknesses. The best distance and the best thickness are effective to mitigate attenuation of the radar signal to within approximately thirty percent of a minimum attenuation that exists across the range of distances and the range of thicknesses for the frequency of the radar signal and the steering angle of the radar signal.

Aspects described below also include a system comprising an attenuator and a radar system. The attenuator has a thickness and semi-transparent material that attenuates a radar signal. The radar system is located on a side of the attenuator. The radar system determines a desired frequency and a desired steering angle of the radar signal based on the thickness of the attenuator and a distance between the attenuator and the radar system. In addition, the radar system transmits the radar signal using the desired frequency and the desired steering angle effective to detect a target that is located on an opposite side of the attenuator.

Aspects described below also include a method comprising determining, by a radar system, a thickness of an attenuator that is located between the radar system and a target. The attenuator has a semi-transparent material that attenuates a radar signal. The method also includes determining, by the radar system, a distance between the attenuator and the radar system. Based on the thickness of the attenuator and the distance between the attenuator and the radar system, a desired frequency and a desired steering angle of the radar signal that mitigates attenuation of the radar signal through the attenuator is determined. Using the desired frequency and the desired steering angle, the method further includes transmitting the radar signal effective to detect the target through the attenuator.

Aspects described below also include a system comprising means for determining a characteristic of an attenuator or a property of a radar signal to mitigate attenuation of the radar signal that passes through the attenuator.

