Motion/vibration sensor
A motion/vibration sensor includes a transmit/receive antenna unit, an oscillation unit and a frequency-mixing unit. The transmit/receive antenna unit receives an output signal from the oscillation unit and transmits a detection signal toward at least one object. The detection signal is reflected by the object as a reflected detection signal and received by the transmit/receive antenna unit. The oscillation unit receives the reflected detection signal from the transmit/receive antenna unit for self-injection locking; and the frequency-mixing unit receives the reflected detection signal from the transmit/receive antenna unit for frequency demodulation. The frequency-mixing unit mixes and demodulates the reflected detection signal from the transmit/receive antenna unit with the output signal from the oscillation unit into a baseband output signal which represents a motion/vibration information.
1. A motion/vibration sensor, including:
a transmit/receive antenna unit;
an oscillation unit, coupled to the transmit/receive antenna unit; and
a frequency-mixing unit coupled to the transmit/receive antenna unit and the oscillation unit;
wherein the transmit/receive antenna unit receives an output signal from the oscillation unit and transmits a detection signal toward at least one object according to the output signal;
the detection signal is reflected by the object as a reflected detection signal and received by the transmit/receive antenna unit;
the oscillation unit receives the reflected detection signal from the transmit/receive antenna unit for self-injection locking and the frequency-mixing unit receives the reflected detection signal from the transmit/receive antenna unit for frequency demodulation; and
the frequency-mixing unit mixes and demodulates the reflected detection signal from the transmit/receive antenna unit with the output signal from the oscillation unit into a baseband output signal which represents a motion/vibration information.
2. The motion/vibration sensor according to claim 1 , further including:
a processing unit, coupled to the oscillation unit and the frequency-mixing unit, for receiving the baseband output signal from the frequency-mixing unit;
the processing unit controls an operation frequency of the oscillation unit and processes the baseband output signal from the frequency-mixing unit to obtain the motion/vibration information.
3. The motion/vibration sensor according to claim 2 , wherein the oscillation unit includes:
a first one of a pair of differential signal output ports, for outputting the output signal to the transmit/receive antenna unit and receiving the reflected detection signal from the transmit/receive antenna unit;
a second one of the pair of differential signal output ports, for sending the output signal to the frequency-mixing unit; and
a voltage input port, coupled to the processing unit, for receiving an analog control voltage from the processing unit.
4. The motion/vibration sensor according to claim 2 , wherein the oscillation unit includes:
a single-ended signal output port, for outputting the output signal to the transmit/receive antenna unit and the frequency-mixing unit;
an injection signal input port, for receiving the reflected detection signal from the transmit/receive antenna unit; and
a voltage input port, coupled to the processing unit, for receiving an analog control voltage from the processing unit.
5. The motion/vibration sensor according to claim 2 , wherein the oscillation unit includes:
a first one of a pair of differential signal output ports, for outputting the output signal to the transmit/receive antenna unit;
a second one of the pair of differential signal output ports, for outputting the output signal to the frequency-mixing unit;
an injection signal input port, for receiving the reflected detection signal from the transmit/receive antenna unit; and
a voltage input port, coupled to the processing unit, for receiving an analog control voltage from the processing unit.
6. The motion/vibration sensor according to claim 2 , wherein the frequency-mixing unit includes:
a mixer, coupled to the transmit/receive antenna unit and the oscillation unit, for mixing the reflected detection signal from the transmit/receive antenna unit and the output signal from the oscillation unit; and
a low pass filter, coupled to the mixer and the processing unit, for performing a low-pass filtering on a mixing signal from the mixer to generate the baseband output signal and output the baseband output signal to the processing unit.
7. The motion/vibration sensor according to claim 1 , wherein the transmit/receive antenna unit includes:
a first antenna, for transmitting the detection signal and receiving the reflected detection signal.
8. The motion/vibration sensor according to claim 1 , wherein the transmit/receive antenna unit includes:
a first antenna, for transmitting the detection signal; and
a second antenna, for receiving the reflected detection signal.
9. The motion/vibration sensor according to claim 1 , wherein the transmit/receive antenna unit includes:
an electrical-to-optical converter, for converting the output signal from the oscillation unit to an optical detection wave; and
an optical-to-electrical converter, for converting the reflected detection signal into a voltage signal and sending the voltage signal to the oscillation unit and the frequency-mixing unit.
10. A motion/vibration sensor, including:
a transmit/receive antenna unit;
an oscillation unit, coupled to the transmit/receive antenna unit; and
a frequency-mixing unit coupled to the transmit/receive antenna unit and the oscillation unit;
wherein the oscillation unit outputs a first output signal to the transmit/receive antenna unit and outputs a second output signal to the frequency-mixing unit;
the transmit/receive antenna unit receives the first output signal and transmits a detection signal toward at least one object according to the first output signal;
the transmit/receive antenna unit receives a reflected detection signal from the at least one object which reflects the detection signal as the reflected detection signal;
the transmit/receive antenna unit receives the reflected detection signal as a first injection signal and a second injection signal;
the oscillation unit receives the first injection signal from the transmit/receive antenna unit for self-injection locking;
the frequency-mixing unit mixes and demodulates the second injection signal from the transmit/receive antenna unit with the second output signal from the oscillation unit into a baseband output signal which represents a motion/vibration information.
11. The motion/vibration sensor according to claim 10 , further including:
a processing unit, coupled to the oscillation unit and the frequency-mixing unit, for receiving the baseband output signal from the frequency-mixing unit;
wherein the processing unit controls an operation frequency of the oscillation unit and processes the baseband output signal from the frequency-mixing unit to obtain the motion/vibration information.
12. The motion/vibration sensor according to claim 11 , wherein the oscillation unit includes:
a first one of a pair of differential signal output ports, for outputting the first output signal to the transmit/receive antenna unit and receiving the first injection signal from the transmit/receive antenna unit; and
a second one of the pair of differential signal output ports, for outputting the second output signal to the frequency-mixing unit.
13. The motion/vibration sensor according to claim 11 , wherein the oscillation unit includes:
a first one of a pair of differential signal output ports, for outputting the first output signal to the transmit/receive antenna unit;
a second one of the pair of differential signal output ports, for outputting the second output signal to the frequency-mixing unit; and
an injection signal input port, for receiving the first injection signal from the transmit/receive antenna unit.
14. The motion/vibration sensor according to claim 11 , wherein the frequency-mixing unit includes:
a mixer, coupled to the transmit/receive antenna unit and the oscillation unit, for mixing the second injection signal from the transmit/receive antenna unit and the second output signal from the oscillation unit; and
a low pass filter, coupled to the mixer and the processing unit, for performing a low-pass filtering on a mixing signal from the mixer to generate the baseband output signal and output the baseband output signal to the processing unit.
15. The motion/vibration sensor according to claim 11 , wherein the oscillation unit includes:
a single-ended signal output port, for outputting the first output signal to the transmit/receive antenna unit and the second output signal to the frequency-mixing unit; and
an injection signal input port, for receiving the first injection signal from the transmit/receive antenna unit.
16. The motion/vibration sensor according to claim 11 , wherein the oscillation unit includes:
a voltage input port for receiving a control voltage from the processing unit.
17. The motion/vibration sensor according to claim 10 , wherein the transmit/receive antenna unit includes:
a first antenna, for transmitting the detection signal and receiving the reflected detection signal.
18. The motion/vibration sensor according to claim 10 , wherein the transmit/receive antenna unit includes:
a first antenna, for transmitting the detection signal; and
a second antenna, for receiving the reflected detection signal.
19. The motion/vibration sensor according to claim 10 , wherein the transmit/receive antenna unit includes:
an electrical-to-optical converter, for converting the first output signal from the oscillation unit to an optical detection wave; and
an optical-to-electrical converter, for converting the reflected detection signal into a voltage signal and sending the voltage signal as the first injection signal and the second injection signal.