Abstract: A radiation pattern of a phased array antenna, comprising a plurality of antenna elements, may be dynamically modified using phase shifters to apply variable phase shifts between antenna elements. In a phased array antenna designed for airborne applications, the phase shifters may be required to enable a fine phase-shifting resolution and to operate over a wide temperature range. The phase shifters may also be required to perform while exhibiting small process variations, small form factor, low power consumption, and low loss. One possible solution to this is a passive vector-interpolating phase shifter configured to exhibit such characteristics.

Abstract: In an illustrative integrated circuit, a chirp generator provides a chirp signal having linearly-ramped chirp intervals, while a shift frequency generator provides a signal having a different shift frequency during each of multiple segments in each chirp interval. A modulator combines the signals to derive a segmented chirp signal having multiple linearly-ramped chirp segments in each chirp interval. The modulator may be a single sideband modulator to provide frequency up-shifted and frequency down-shifted chirp segments. The segmented chirp signal may be suppressed during resettling intervals of the original chirp signal.

Abstract: An improved circuit configuration is disclosed for calibrating and/or verifying the operation of phase shifters in a phased array radar system. In one illustrative embodiment, a method includes: (i) programming a set of phase shifters to convert a radio frequency signal into a set of channel signals; (ii) splitting off a monitor signal from each channel signal while coupling the set of channel signals to a set of antenna feeds; and (iii) while taking the monitor signals in pairs associated with adjacent channels, measuring a relative phase between each pair of monitor signals.

Abstract: Disclosed active reflector apparatus and methods that inhibit self-induced oscillation. One illustrative apparatus embodiment includes an amplifier and an adjustable phase shifter. The amplifier amplifies a receive signal to generate a transmit signal, the transmit signal causing interference with the receive signal. The adjustable phase shifter modifies the phase of the transmit signal relative to that of the receive signal to inhibit oscillation. A controller may periodically test a range of settings for the adjustable phase shifter to identify undesirable phase shifts prone to self-induced oscillation, and may maintain the phase shift setting at a value that inhibits oscillation.

Abstract: In an illustrative integrated circuit, a chirp generator provides a chirp signal having linearly-ramped chirp intervals, while a shift frequency generator provides a signal having a different shift frequency during each of multiple segments in each chirp interval. A modulator combines the signals to derive a segmented chirp signal having multiple linearly-ramped chirp segments in each chirp interval. The modulator may be a single sideband modulator to provide frequency up-shifted and frequency down-shifted chirp segments. The segmented chirp signal may be suppressed during resettling intervals of the original chirp signal.

Abstract: A split-steer amplifier with an invertible phase output, includes a first transistor having its base coupled to a positive node of an input port, its emitter coupled to ground, and collector connected to a positive intermediate node; a second transistor having its base coupled to a negative node of the input port, its emitter coupled to ground, and collector connected to a negative intermediate node; and multiple output ports each having a transistor arrangement operable to couple a positive node of that output port to the positive intermediate node and a negative node of that output port to the negative intermediate node, operable to couple the positive node of that output port to the negative intermediate node and the negative node of that output port to the positive intermediate node, and operable to decouple the positive node and the negative node of that output port from the intermediate nodes.

Abstract: Disclosed active reflector apparatus and methods that inhibit self-induced oscillation. One illustrative apparatus embodiment includes an amplifier and an adjustable phase shifter. The amplifier amplifies a receive signal to generate a transmit signal, the transmit signal causing interference with the receive signal. The adjustable phase shifter modifies the phase of the transmit signal relative to that of the receive signal to inhibit oscillation. A controller may periodically test a range of settings for the adjustable phase shifter to identify undesirable phase shifts prone to self-induced oscillation, and may maintain the phase shift setting at a value that inhibits oscillation.

Abstract: A radiation pattern of a phased array antenna, comprising a plurality of antenna elements, may be dynamically modified using phase shifters to apply variable phase shifts between antenna elements. In a phased array antenna designed for airborne applications, the phase shifters may be required to enable a fine phase-shifting resolution and to operate over a wide temperature range. The phase shifters may also be required to perform while exhibiting small process variations, small form factor, low power consumption, and low loss. One possible solution to this is a passive vector-interpolating phase shifter configured to exhibit such characteristics.

Abstract: In an illustrative integrated circuit, a chirp generator provides a chirp signal having linearly-ramped chirp intervals, while a shift frequency generator provides a signal having a different shift frequency during each of multiple segments in each chirp interval. A modulator combines the signals to derive a segmented chirp signal having multiple linearly-ramped chirp segments in each chirp interval. The modulator may be a single sideband modulator to provide frequency up-shifted and frequency down-shifted chirp segments. The segmented chirp signal may be suppressed during resettling intervals of the original chirp signal.

Abstract: A split-steer amplifier with an invertible phase output, includes a first transistor having its base coupled to a positive node of an input port, its emitter coupled to ground, and collector connected to a positive intermediate node; a second transistor having its base coupled to a negative node of the input port, its emitter coupled to ground, and collector connected to a negative intermediate node; and multiple output ports each having a transistor arrangement operable to couple a positive node of that output port to the positive intermediate node and a negative node of that output port to the negative intermediate node, operable to couple the positive node of that output port to the negative intermediate node and the negative node of that output port to the positive intermediate node, and operable to decouple the positive node and the negative node of that output port from the intermediate nodes.

Abstract: Illustrative methods and circuits to verify operation of phase shifters. One illustrative method includes: obtaining a first set of in-phase and quadrature components (I1,Q1) of a phase shifter output signal with a first setting; measuring a second set of components (I2,Q2) with a second setting, the second setting being offset from the first by a predetermined phase difference; and combining the first and second sets to determine whether their relationship corresponds to the predetermined phase difference. An illustrative transmitter includes: a phase shifter, an I/Q mixer, and a processing circuit. The phase shifter converts a transmit signal into an output signal having a programmable phase shift. The I/Q mixer mixes the output signal with a reference signal to obtain in-phase and quadrature components of the output signal. The processing circuit is coupled to the I/Q mixer implement the disclosed method.

Abstract: Automotive radar methods and systems for enhancing resistance to interference using a built-in self-test (BIST) module. In one illustrative embodiment, an automotive radar transceiver includes: a signal generator that generates a transmit signal; a modulator that derives a modulated signal from the transmit signal using at least one of phase and amplitude modulation; at least one receiver that mixes the transmit signal with a receive signal to produce a down-converted signal, the receive signal including the modulated signal during a built-in self-test (BIST) mode of operation; and at least one transmitter that drives a radar antenna with a selectable one of the transmit signal and the modulated signal.

Abstract: A split-steer amplifier with an invertible phase output, includes a first transistor having its base coupled to a positive node of an input port, its emitter coupled to ground, and collector connected to a positive intermediate node; a second transistor having its base coupled to a negative node of the input port, its emitter coupled to ground, and collector connected to a negative intermediate node; and multiple output ports each having a transistor arrangement operable to couple a positive node of that output port to the positive intermediate node and a negative node of that output port to the negative intermediate node, operable to couple the positive node of that output port to the negative intermediate node and the negative node of that output port to the positive intermediate node, and operable to decouple the positive node and the negative node of that output port from the intermediate nodes.

Abstract: A radiation pattern of a phased array antenna, comprising a plurality of antenna elements, may be dynamically modified using phase shifters to apply variable phase shifts between antenna elements. In a phased array antenna designed for airborne applications, the phase shifters may be required to enable a fine phase-shifting resolution and to operate over a wide temperature range. The phase shifters may also be required to perform while exhibiting small process variations, small form factor, low power consumption, and low loss. One possible solution to this is a passive vector-interpolating phase shifter configured to exhibit such characteristics.

Abstract: An improved circuit configuration is disclosed for calibrating and/or verifying the operation of phase shifters in a phased array radar system. In one illustrative embodiment, a method includes: (i) programming a set of phase shifters to convert a radio frequency signal into a set of channel signals; (ii) splitting off a monitor signal from each channel signal while coupling the set of channel signals to a set of antenna feeds; and (iii) while taking the monitor signals in pairs associated with adjacent channels, measuring a relative phase between each pair of monitor signals.

Abstract: Automotive radar methods and systems for enhancing resistance to interference using a built-in self-test (BIST) module. In one illustrative embodiment, an automotive radar transceiver includes: a signal generator that generates a transmit signal; a modulator that derives a modulated signal from the transmit signal using at least one of phase and amplitude modulation; at least one receiver that mixes the transmit signal with a receive signal to produce a down-converted signal, the receive signal including the modulated signal during a built-in self-test (BIST) mode of operation; and at least one transmitter that drives a radar antenna with a selectable one of the transmit signal and the modulated signal.

Abstract: A radiation pattern of a phased array antenna, comprising a plurality of antenna elements, may be dynamically modified using phase shifters to apply variable phase shifts between antenna elements. In a phased array antenna designed for airborne applications, the phase shifters may be required to enable a fine phase-shifting resolution and to operate over a wide temperature range. The phase shifters may also be required to perform while exhibiting small process variations, small form factor, low power consumption, and low loss. One possible solution to this is a passive vector-interpolating phase shifter configured to exhibit such characteristics.

Abstract: In an illustrative integrated circuit, a chirp generator provides a chirp signal having linearly-ramped chirp intervals, while a shift frequency generator provides a signal having a different shift frequency during each of multiple segments in each chirp interval. A modulator combines the signals to derive a segmented chirp signal having multiple linearly-ramped chirp segments in each chirp interval. The modulator may be a single sideband modulator to provide frequency up-shifted and frequency down-shifted chirp segments. The segmented chirp signal may be suppressed during resettling intervals of the original chirp signal.

Abstract: An improved circuit configuration is disclosed for calibrating and/or verifying the operation of phase shifters in a phased array radar system. In one illustrative embodiment, a method includes: (i) programming a set of phase shifters to convert a radio frequency signal into a set of channel signals; (ii) splitting off a monitor signal from each channel signal while coupling the set of channel signals to a set of antenna feeds; and (iii) while taking the monitor signals in pairs associated with adjacent channels, measuring a relative phase between each pair of monitor signals.

Abstract: A split-steer amplifier with an invertible phase output, includes a first transistor having its base coupled to a positive node of an input port, its emitter coupled to ground, and collector connected to a positive intermediate node; a second transistor having its base coupled to a negative node of the input port, its emitter coupled to ground, and collector connected to a negative intermediate node; and multiple output ports each having a transistor arrangement operable to couple a positive node of that output port to the positive intermediate node and a negative node of that output port to the negative intermediate node, operable to couple the positive node of that output port to the negative intermediate node and the negative node of that output port to the positive intermediate node, and operable to decouple the positive node and the negative node of that output port from the intermediate nodes.