A radar transceiver is provided. The radar transceiver includes an electrical balance duplexer that is coupled to a transmission node of a transmission path, a reception node of a reception path, and an antenna node and that is configured to isolate the transmission path from the reception path. The electrical balance duplexer includes a hybrid transformer network and a non-tunable balancing impedance. The non-tunable balancing impedance is configured to provide a fixed impedance value that corresponds to an impedance value at the antenna node.

A radar apparatus includes a plurality of transmit antennas that transmits a plurality of transmission signals using a multiplexing transmission, and a transmission circuit that applies phase rotation amounts corresponding to combinations of Doppler shift amounts and code sequences to the plurality of transmission signals. Each of the plurality of transmission signals is assigned a different combination among the combinations. The combinations include at least one combination of different numbers of multiplexing by the code sequences.

A multi-pixel terahertz transceiver is constructed using a stack of semiconductor layers that communicate using vias defined within the semiconductor layers. By using a stack of semiconductor layers, the various electrical functions of each layer can be tested easily without having to assemble the entire transceiver. In addition, the design allows the production of a transceiver having pixels set 10 mm apart.

Radar transmitter includes a plurality of transmit antennas that transmit a plurality of transmission signals using a multiplexing transmission, and a transmission circuit. The transmission circuit applies phase rotation amounts corresponding to combinations of Doppler shift amounts and code sequences to the plurality of transmission signals. Each of the combinations of the Doppler shift amounts and the code sequences has at least one different from other combination. The number of multiplexes of the code sequence corresponding to at least one of the Doppler shift amounts in the combinations is different from the number of multiplexing of code sequences corresponding to the remaining Doppler shift amounts.

Multi-input downconversion mixers, systems, and methods are provided with input switching in the intermediate frequency or baseband domain. One illustrative mixer embodiment includes: multiple differential pairs of transistors and multiple pairs of switches. Each differential transistor pair has their bases or gates driven by a differential reference signal, their emitters or sources connected to a common node having a current or voltage driven based on a respective one of multiple receive signals, and their collectors or drains providing a product of the differential reference signal with the respective one of the multiple receive signals. Each of the switch pairs selectively couples differential output nodes to the collectors or drains of a respective one of the multiple differential pairs, enabling the differential output nodes to convey an output signal that is a sum of products from selected ones of the multiple differential pairs.

In a ranging module, a first calculator calculates a distance from a processed signal corresponding to a current pixel. A determiner determines whether the distance calculated by the first calculator differs from a preset limit distance. A re-extractor is configured to, in response to the determiner determining that the distance differs from the preset limit distance, extract pieces of data of processing sections each corresponding to a sweep time of a transmission wave from a time-series of the processed signals saved in a data storage corresponding from a pixel previous to the current pixel in a scanning direction of a scanner to the current pixel while shifting the processing sections one after the other by a time period shorter than the sweep time. A second calculator calculates the distance from the data of each processing section extracted by the re-extractor.

Multi-input downconversion mixers, systems, and methods are provided with input switching in the intermediate frequency or baseband domain. One illustrative mixer embodiment includes: multiple differential pairs of transistors and multiple pairs of switches. Each differential transistor pair has their bases or gates driven by a differential reference signal, their emitters or sources connected to a common node having a current or voltage driven based on a respective one of multiple receive signals, and their collectors or drains providing a product of the differential reference signal with the respective one of the multiple receive signals. Each of the switch pairs selectively couples differential output nodes to the collectors or drains of a respective one of the multiple differential pairs, enabling the differential output nodes to convey an output signal that is a sum of products from selected ones of the multiple differential pairs.

A radar apparatus includes a plurality of transmit antennas that transmits a plurality of transmission signals using a multiplexing transmission, and a transmission circuit that applies phase rotation amounts corresponding to combinations of Doppler shift amounts and code sequences to the plurality of transmission signals. Each of the plurality of transmission signals is assigned a different combination among the combinations. The combinations include at least one combination of different numbers of multiplexing by the code sequences.

Radar circuitry can include an isolator and a mixer. The isolator can isolate a transmission signal path and a reception signal path from each other, and generate a mixing (e.g. oscillation) signal based on a transmission signal. The isolator can be coupled to the mixer such that the drive signal drives the mixer (e.g. serves as the local oscillation signal of the mixer). The mixer mixes a received signal and the drive signal to generate a converted signal (e.g. a down-converted signal). The isolator can be a hybrid transformer or electrically balanced duplexer.

A radar apparatus includes a plurality of transmit antennas that transmits a plurality of transmission signals using a multiplexing transmission, and a transmission circuit that applies phase rotation amounts corresponding to combinations of Doppler shift amounts and code sequences to the plurality of transmission signals. Each of the plurality of transmission signals is assigned a different combination among the combinations. The combinations include at least two combinations of a same number of multiplexing by the code sequences.