US 9,157,996 B1 · Multiple ultrasonic preamplifiers with independent automatic gain control

Abstract

Multiple signals are received from multiple receivers in a motion sensor. Each signal is amplified and undergoes a gain adjustment individually to generate multiple preamplified received ultrasonic signals. A separate demodulator circuit receives a different preamplified received ultrasonic signal and generates a sum of the demodulated signals and a difference between the demodulated signals. A low pass filter corresponding to a demodulator circuit removes the sum of the demodulated signals. The mixer circuit combines the difference between the demodulated signals to generate an integrated circuit. The gain of each preamplifier may be adjusted based on a sensitivity setting, target levels of the preamplifier, and a level of a preamplified ultrasonic signal, resulting in an integrated motion sign that originated from multiple signals to different receivers in the sensor housing.

Claims27

Dependent claims

A method for generating an integrated signal, the method comprising:

receiving, via a first preamplifier, a first signal from a first receiver of a plurality of receivers;
processing, using a first demodulator, a first amplified signal to generate a first demodulated signal, wherein the first amplified signal is derived from the first signal;
receiving, via a second preamplifier, a second signal from a second receiver of the plurality of receivers;
processing, using a second demodulator, a second amplified signal to generate a second demodulated signal, wherein the second amplified signal is derived from the second signal;
processing the first demodulated signal and the second demodulated signal to generate the integrated signal;
and
determining a target level for the first preamplifier and the second preamplifier, wherein the target level comprises a minimum target level and a maximum target level.

4 more elements

An ultrasonic occupancy sensor, comprising:

a first demodulator configured to generate a first demodulated signal, wherein the first demodulated signal is derived from a first signal received by a first receiver;
a second demodulator circuit configured to generate a second demodulated signal, wherein the second demodulated signal is derived from a second signal received by a second receiver;
and
a mixer circuit communicably coupled to the first demodulator and the second demodulator, wherein the mixer circuit is configured to:
receive a difference between the first demodulated signal and the second demodulated signal;
and
generate an integrated signal.

4 more elements

Dependencies are inferred from the claim text.

Multiple ultrasonic preamplifiers with independent automatic gain control

Life of this patent

Multiple ultrasonic preamplifiers with independent automatic gain control

Life of this patent

Abstract

Claims27