Frequency mixer for a doppler radar module

摘要

A frequency mixer for a Doppler radar module with directional recognition, can be operated with a single transmitting and receiving antenna. It is thereby possible to create a Doppler radar module with low space requirements even for transmitting and receiving frequencies below 5 GHz. In the frequency mixer, a first microstrip line is coupled to a first terminal of a first diode and a second microstrip line is coupled to a first terminal of a second diode. The two microstrip lines are connected to each other through a capacitor. An antenna is coupled to the first microstrip line and an oscillator is coupled to the second microstrip line. Second terminals of each of the diodes are connected to a fixed potential in an electrically conductive manner. A phase comparator is coupled to the two microstrip lines.