A sensor front end for an electronic radar sensor is disclosed that provides
for
a lower parts count while providing technical functionality by using multifunction
parts, i.e., parts that are used both in transmitting and receiving. The sensor
front end includes a continuous wave signal source that functions as a signal source
when the front end is transmitting a signal and as a local oscillator when the
front end is receiving a signal. The sensor front end also includes a tri-mode
mixer that functions as a phase-modulator and transmit switch when the front end
is transmitting a signal and as a mixer/down-converter when the front end is receiving
a signal. The sensor front end further includes a common aperture antenna that
acts as both a transmitting antenna for transmitting a sensor signal and for receiving
a reflected signal from a object. A phase shifter can be added to provide a predetermined
phase shift in the transmitted sensor signal, the received reflected signal, or
both, such that in-phase and quadrature signal components are provided. In addition,
phase coding may be added to the signal to reduce the degenerative impact of interfering
signals. A receiver module is coupled to the tri-mode mixer such that, when receiving
a reflected signal, the receiver provides a baseband sensor output signal that
can be used to determined the position and velocity of the object. A sampling module
can be added such that the sensor output signal is sampled and provided as an analog
signal, or the sampled sensor output signal can be provided to an analog-to-digital
converter to convert the sensor output signal into a digital format, or both.