Self-injection-locking monopulse radar

A self-injection-locking monopulse radar comprising:

• a self-injection-locking oscillator (SILO) configured to generate an oscillation signal;
• a transmit antenna coupled to the SILO and configured to receive and transmit the oscillation signal to an object as a transmitted signal;
• two receive antennas configured to receive a reflected signal reflected from the object as a first echo signal and a second echo signal, respectively;
• a hybrid coupler electrically connected to the two receive antennas and the SILO and configured to receive the first and second echo signals and output a difference signal and a sum signal, the difference signal is configured to be injected into the SILO to achieve a SIL state;
• a first demodulator coupled to the SILO and configured to receive and demodulate the oscillation signal to produce a first demodulated signal;
• a second demodulator coupled to the hybrid coupler and the SILO to receive the sum signal and the oscillation signal and configured to demodulate the sum signal using the oscillation signal as a reference signal to produce a second demodulated signal;
• and
• a processor electrically connected to the first and second demodulators and configured to receive and process the first and second demodulated signals to produce a monopulse ratio signal,
• wherein the first demodulator is configured to frequency-demodulate the oscillation signal, and the second demodulator is configured to phase-demodulate the sum signal using the oscillation signal as the reference signal.