Low noise amplifier for multiple channels
First Claim
Patent Images
1. A signal transmission system comprising:
- an amplifier configured to amplify an input signal having a plurality of different channels to produce an amplified input signal having the plurality of different channels;
a demodulator group configured to demodulate the amplified input signal to produce at least one demodulated signal for each channel, demodulating causing each demodulated signal to have noise relating to at least one other channel, the demodulator group comprising;
a first-channel demodulator comprising a switching arrangement controlled by a first-channel drive signal to produce a first baseband signal; and
a second-channel demodulator comprising a switching arrangement controlled by a second-channel drive signal to produce a second baseband signal;
a first filter in communication with the first-channel demodulator and configured to mitigate the noise on the first baseband signal;
a second filter in communication with the second-channel demodulator and configured to mitigate the noise on the second baseband signal;
a first output coupled to the first filter and configured to transmit a filtered version of the first baseband signal; and
a second output coupled to the second filter and configured to transmit a filtered version of the second baseband signal.
1 Assignment
0 Petitions
Accused Products
Abstract
An amplifier system has an amplifier for amplifying a plurality of input signals from a plurality of different channels, and a plurality of demodulators each operatively coupled with the amplifier for receiving amplified input signals from the amplifier. Each demodulator is configured to demodulate a single amplified input channel signal from a single channel of the plurality of different channels. The system thus also has a plurality of filters, coupled with each of the demodulators, for mitigating the noise.
13 Citations
20 Claims
-
1. A signal transmission system comprising:
-
an amplifier configured to amplify an input signal having a plurality of different channels to produce an amplified input signal having the plurality of different channels; a demodulator group configured to demodulate the amplified input signal to produce at least one demodulated signal for each channel, demodulating causing each demodulated signal to have noise relating to at least one other channel, the demodulator group comprising; a first-channel demodulator comprising a switching arrangement controlled by a first-channel drive signal to produce a first baseband signal; and a second-channel demodulator comprising a switching arrangement controlled by a second-channel drive signal to produce a second baseband signal; a first filter in communication with the first-channel demodulator and configured to mitigate the noise on the first baseband signal; a second filter in communication with the second-channel demodulator and configured to mitigate the noise on the second baseband signal; a first output coupled to the first filter and configured to transmit a filtered version of the first baseband signal; and a second output coupled to the second filter and configured to transmit a filtered version of the second baseband signal. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A method of processing a signal produced by a MEMS device having a beam movable in a plurality of axes, the MEMS device having a first-axis variable capacitor disposed to respond to motion of the beam along a first axis, the first-axis variable capacitor driven by a periodic first-axis drive signal having a first-channel drive frequency, and also having a second-axis variable capacitor disposed to respond to motion of the beam along a second axis, the second-axis variable capacitor driven by a periodic second-axis drive signal having a second-channel drive frequency, the method comprising:
-
providing an amplifier having an amplifier input electrically coupled to the first-axis variable capacitor and the second-axis variable capacitor, to amplify first-axis motion and second-axis motion signals from the first-axis variable capacitor and the second-axis variable capacitor, respectively; providing a plurality of demodulators operatively coupled with the amplifier for receiving amplified input signals from the amplifier, each demodulator comprising a switching arrangement, the plurality of demodulators comprising; a first-channel demodulator coupled to the periodic first-axis drive signal and operable to demodulate the amplified motion signals to produce a first-axis output signal including second-axis noise; and a second-channel demodulator coupled to the periodic second-axis drive signal and operable to demodulate the amplified motion signal to produce a second-axis output signal including first-axis noise; filtering the first-axis output signal through a first-channel low-pass filter coupled to the first-channel demodulator, the first-channel low-pass filter having a cutoff frequency below the frequency of the second-axis noise generated by the second-channel demodulator; and filtering the second-axis output signal noise through a second-channel low-pass filter coupled to the second-channel demodulator, the second-channel low-pass filter having a cutoff frequency below the frequency of the first-axis noise generated by the first-channel demodulator; the filters mitigating the noise on their respective channels. - View Dependent Claims (8, 9, 10, 11, 12, 13)
-
-
14. A signal transmission system comprising:
a demodulator group receiving an output signal of a first stage, the output signal having a plurality of modulated signals associated with a plurality of channels, the demodulator group configured to demodulate the output signal to produce at least one demodulated signal for each channel, the demodulator group comprising; a first-channel demodulator comprising a switching arrangement controlled by a first-channel drive signal to produce a first baseband signal; and a first filter in communication with the first-channel demodulator and configured to mitigate noise on the first baseband signal; a first output coupled to the first filter and configured to transmit a filtered version of the first baseband signal; a second-channel demodulator comprising a switching arrangement controlled by a second-channel drive signal to produce a second baseband signal; a second filter in communication with the second-channel demodulator and configured to mitigate noise on the second baseband signal; and a second output coupled to the second filter and configured to transmit a filtered version of the second baseband signal. - View Dependent Claims (15, 16, 17, 18, 19, 20)
Specification