With the help of high-frequency technology, radar systems can be developed with which the distance to an object can be determined relatively or absolutely. Fields of application are non-contact distance, vibration or layer thickness measurements in industry, or the detection of vital parameters in medical and life science applications. A further area of application is, for example, presence detection in front of doors and for security systems.
When measuring vital parameters, the great advantage is that the measured values can be recorded contactlessly through clothing or bed covers. The radar system can be installed behind covers, so that the person is not aware of the measurement and therefore does not have the feeling of being monitored. In addition to the areas of application for monitoring people, for example in motor cars and beds, countless others are thinkable.
In industrial applications radar also offers many advantages. On the one hand, the component costs for the necessary components have fallen sharply in recent years due to their integration in MMICs (Monolithic Microwave Integrated Circuits) and high-performance microcontrollers, making the systems compact and inexpensive to manufacture. On the other hand, with radar systems it is possible to measure distances contactlessly and simultaneously under harsh environmental conditions. Dust or fog can be penetrated by the electromagnetic waves to a large extent. This results in lower costs and an advantage over conventionally used optical measuring systems.
Extremely sensitive sensors can be constructed using different types of RF resonators. These can be designed either as electroacoustic components or as cavity resonators. The higher the frequency, the smaller the resulting structures. With the knowledge of the exact parameters of the resonator, unknown materials can be characterized. Due to the influence of different physical parameters, a resonance frequency shift occurs, which can be detected extremely fast. With planar resonators, materials can also be characterized in terms of their losses and permittivities. These parameters are decisive for antenna coverage, among other things.