Abstract: In one embodiment, an automated interferometric noise measurement system includes: a signal source adapted to provide a carrier signal; a delay line adapted to delay a first version of the carrier signal to provide a delayed signal to a device-under-test (DUT); a variable attenuator adapted to attenuate a second version of the carrier signal to provide an attenuated signal; a first variable phase-shifter adapted to phase-shift the attenuated signal to provide a first phase-shifted signal; a hybrid coupler adapted to receive an output signal from the DUT and the first phase-shifted signal to provide a carrier-suppressed signal and a carrier-enhanced signal; a low-noise amplifier adapted to amplify the carrier-suppressed signal to provide an amplified signal; a second variable phase-shifter adapted to phase-shift a version of the carrier-enhanced signal to provide a second phase-shifted signal; a first mixer adapted to mix a first version of the amplified signal and the second phase-shifted signal to provide a

Abstract: A distributed receiver in signal communication with an active antenna array is described. The distributed receiver may include an exciter, a plurality of transmit/receive (“T/R”) modules, and a frequency source operable to provide a frequency reference signal to the T/R modules.

Abstract: In one embodiment, a low-noise source includes: a signal source; a variable amplifier adapted to amplify an output signal from the signal source to provide an amplified signal; a feed-forward amplifier adapted to amplify the amplified signal to provide an amplified output signal; a phase noise measurement system adapted to provide a first feedback signal responsive to phase noise in the amplified output signal; and a processor adapted to control the amplification provided by the variable amplifier responsive to the feedback signal so as to minimize phase noise in the amplified output signal.

Abstract: A noise test measurement system configured to measure a noise component of a transmitted RF signal is described. The noise test measurement system may include an antenna, a low-noise amplifier, a local oscillator, a first coupler, a first variable phase-shifter, a first mixer, and a processor.

Abstract: In one embodiment, a low-noise source includes: a signal source; a variable amplifier adapted to amplify an output signal from the signal source to provide an amplified signal; a feed-forward amplifier adapted to amplify the amplified signal to provide an amplified output signal; a phase noise measurement system adapted to provide a first feedback signal responsive to phase noise in the amplified output signal; and a processor adapted to control the amplification provided by the variable amplifier responsive to the feedback signal so as to minimize phase noise in the amplified output signal.

Abstract: In one embodiment, a low-noise source includes: a signal source; a variable amplifier adapted to amplify an output signal from the signal source to provide an amplified signal; a feed-forward amplifier adapted to amplify the amplified signal to provide an amplified output signal; a phase noise measurement system adapted to provide a first feedback signal responsive to phase noise in the amplified output signal; and a processor adapted to control the amplification provided by the variable amplifier responsive to the feedback signal so as to minimize phase noise in the amplified output signal.

Abstract: A noise test measurement system configured to measure a noise component of a transmitted RF signal is described. The noise test measurement system may include an antenna, a low-noise amplifier, a local oscillator, a first coupler, a first variable phase-shifter, a first mixer, and a processor.

Abstract: In one embodiment, an automated interferometric noise measurement system includes: a signal source adapted to provide a carrier signal; a delay line adapted to delay a first version of the carrier signal to provide a delayed signal to a device-under-test (DUT); a variable attenuator adapted to attenuate a second version of the carrier signal to provide an attenuated signal; a first variable phase-shifter adapted to phase-shift the attenuated signal to provide a first phase-shifted signal; a hybrid coupler adapted to receive an output signal from the DUT and the first phase-shifted signal to provide a carrier-suppressed signal and a carrier-enhanced signal; a low-noise amplifier adapted to amplify the carrier-suppressed signal to provide an amplified signal; a second variable phase-shifter adapted to phase-shift a version of the carrier-enhanced signal to provide a second phase-shifted signal; a first mixer adapted to mix a first version of the amplified signal and the second phase-shifted signal to provide a

Abstract: In one embodiment, a low-noise source includes: a signal source; a variable amplifier adapted to amplify an output signal from the signal source to provide an amplified signal; a feed-forward amplifier adapted to amplify the amplified signal to provide an amplified output signal; a phase noise measurement system adapted to provide a first feedback signal responsive to phase noise in the amplified output signal; and a processor adapted to control the amplification provided by the variable amplifier responsive to the feedback signal so as to minimize phase noise in the amplified output signal.

Abstract: A direct downconversion receiver combines a received RF signal and a local oscillator (LO) signal to form a combined signal. The local oscillator signal is also phase-shifted by approximately 90 degrees to form a quadrature signal. A mixer forms the product of the combined signal and the quadrature signal to produce a baseband output signal.

Abstract: A direct downconversion receiver combines a received RF signal and a local oscillator (LO) signal to form a combined signal. The local oscillator signal is also phase-shifted by approximately 90 degrees to form a quadrature signal. A mixer forms the product of the combined signal and the quadrature signal to produce a baseband output signal.