Abstract: A radar device includes radar transmission and receiving circuits. The radar transmission circuit transmits one or more transmission signals, each having a transmission period Tr. The radar receiving circuit receives one or more reflected signals in which the transmission signals are reflected by an object and estimates a direction of the object based on the reflected signals. The radar transmission circuit includes Nt transmission antennas. A control circuit sets a transmission gap period between a first and second periods, with the transmission gap period being a period during which the transmission signals are not transmitted. The first period is equal to an integral multiple of a period Np, the period Np is equal to or more than Nt times the transmission period Tr, and the second period is set after the first period and is equal to an integral multiple of the period Np.

Abstract: The target detection accuracy of a radar apparatus is improved. The radar apparatus includes transmission circuitry, which, in operation, transmits a transmission signal using a plurality of transmit antennas, and reception circuitry, which, in operation, receives using a plurality of receive antennas a reflected wave signal that is the transmission signal reflected by an object, in which the plurality of transmit antennas include at least one first transmit antenna and a plurality of second transmit antennas, and, in a first direction, an absolute value of a difference between, on one hand, a spacing between the at least one first transmit antenna and a phase center of those of the plurality of second transmit antennas which are used for beam synthesis, and, on another hand, a spacing between adjacent receive antennas of the plurality of receive antennas is a defined value based on a wavelength of the plurality of transmission signals.

Abstract: A radar transmitter transmits a radar signal through a transmitting array antenna at a predetermined transmission period, and a radar receiver receives a reflected wave signal which is the radar signal reflected by a target through a receiving array antenna. A transmitting array antenna and a receiving array antenna each include multiple subarray elements, the subarray elements in the transmitting array antenna and the receiving array antenna are linearly arranged in a first direction, each subarray element includes multiple antenna elements, the subarray element has a dimension larger than a predetermined antenna element spacing in the first direction, and an absolute value of a difference between a subarray element spacing of the transmitting array antenna and a subarray element spacing of the receiving array antenna is equal to the predetermined antenna element spacing.

Abstract: 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.

Abstract: A radar transmitter transmits a radar signal through a transmitting array antenna at a predetermined transmission period, and a radar receiver receives a reflected wave signal which is the radar signal reflected by a target through a receiving array antenna. A transmitting array antenna and a receiving array antenna each include multiple subarray elements, the subarray elements in the transmitting array antenna and the receiving array antenna are linearly arranged in a first direction, each subarray element includes multiple antenna elements, the subarray element has a dimension larger than a predetermined antenna element spacing in the first direction, and an absolute value of a difference between a subarray element spacing of the transmitting array antenna and a subarray element spacing of the receiving array antenna is equal to the predetermined antenna element spacing.

Abstract: A radar transmitter transmits a radar signal through a transmitting array antenna at a predetermined transmission period, and a radar receiver receives a reflected wave signal which is the radar signal reflected by a target through a receiving array antenna. A transmitting array antenna and a receiving array antenna each include multiple subarray elements, the subarray elements in the transmitting array antenna and the receiving array antenna are linearly arranged in a first direction, each subarray element includes multiple antenna elements, the subarray element has a dimension larger than a predetermined antenna element spacing in the first direction, and an absolute value of a difference between a subarray element spacing of the transmitting array antenna and a subarray element spacing of the receiving array antenna is equal to the predetermined antenna element spacing.

Abstract: 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.

Abstract: Provided is a radar apparatus whose performance is enhanced. The radar apparatus, includes: signal generation circuitry, which, in operation, generates a plurality of chirp signals; and a transmission antenna, which, in operation, transmits the plurality of chirp signals. The signal generation circuitry configures a transmission delay for the plurality of chirp signals for each of a predetermined number of transmission periods, where the predetermined number is greater than or equal to two. The signal generation circuitry changes a center frequency of the plurality of chirp signals for each of the predetermined number of transmission periods.

Abstract: A transmitting array antenna includes a second antenna group placed in a position inside a first antenna group in a first direction and a position different from the first antenna group in a second direction. A receiving array antenna includes a fourth antenna placed in a position outside a third antenna group arranged in the first direction and a position different from the third antenna group in the second direction. An interelement spacing between a receiving antenna of the third antenna group located at an end on a second side is identical to an interelement spacing in the first direction between a transmitting antenna of the first antenna group on the first side and each of the second antenna group. In a case where the first antenna group and the third antenna group are identical in position in the second direction, positions of antennas are different.

Abstract: Provided is a radar apparatus that detects a target object with high accuracy. The radar apparatus includes: transmission circuitry, which, in operation, alternately outputs a first transmission signal with a first central frequency and a second transmission signal with a second central frequency higher than the first central frequency for each transmission period; and one or a plurality of transmission antennas, which, in operation, transmit the fast transmission signal and the second transmission signal. The second central frequency is higher than a frequency (1+1/Nc) times the first central frequency, where Nc is an integer indicating a number of times of transmission of each of the first transmission signal and the second transmission signal for the each transmission period within a predetermined duration.

Abstract: A radar device includes radar transmission and receiving circuits. The radar transmission circuit transmits one or more transmission signals, each having a transmission period Tr. The radar receiving circuit receives one or more reflected signals in which the transmission signals are reflected by an object and estimates a direction of the object based on the reflected signals. The radar transmission circuit includes Nt transmission antennas. A control circuit sets a transmission gap period between a first and second periods, with the transmission gap period being a period during which the transmission signals are not transmitted. The first period is equal to an integral multiple of a period Np, the period Np is equal to or more than Nt times the transmission period Tr, and the second period is set after the first period and is equal to an integral multiple of the period Np.

Abstract: This radar device comprises a signal generation circuit for generating a baseband signal, a code generation circuit for generating a plurality of code sequences, a phase rotation circuit for applying phase rotation based on one of the code sequences from among the plurality of code sequences to the baseband signal and generating a plurality of code multiplexed transmission signals, and a plurality of transmission antennas for transmitting the plurality of transmission signals. The code length of the plurality of code sequences is greater than the code multiplexing number of the plurality of transmission signals.

Abstract: 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.

Abstract: A radar apparatus includes a plurality of transmission antennae and a radar transmitter that transmits transmission signals by using the plurality of transmission antennae. In a virtual reception array including a plurality of virtual antennae formed of a plurality of reception antennae and the plurality of transmission antennae, disposition positions of at least two of the virtual antennae are the same as each other, and, transmission intervals of the transmission signals that are sequentially transmitted from transmission antennae corresponding to the at least two virtual antennae among the plurality of transmission antennae are an equal interval.

Abstract: 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.

Abstract: A radar transmitter includes: a plurality of transmission antennas that transmit a transmission signal; and a transmission circuit that applies a phase rotation amount corresponding to a Doppler shift amount and a code sequence to the transmission signal to perform multiplexing transmission of the transmission signal from the plurality of transmission antennas. Each of the plurality of transmission antennas is associated with each of a plurality of combinations of the Doppler shift amount and the code sequence. Each of the plurality of combination is different at least one of the Doppler shift amount and the code sequence, and the Doppler shift amounts of those of the plurality of combinations which are associated respectively with at least two transmission antennas of the plurality of transmission antennas are the same Doppler shift amount, the at least two transmission antennas being a first sub-array antenna.

Abstract: The radar apparatus includes: a plurality of transmission antennas that transmit a transmission signal; and a transmission circuit that applies a phase rotation amount corresponding to a Doppler shift amount and a code sequence to the transmission signal to perform multiplexing transmission of the transmission signal from the plurality of transmission antennas. A transmission delay of the transmission signal is set for a transmission period of the transmission signal. Each of the plurality of transmission antennas is associated with a combination of the Doppler shift amount and the code sequence such that at least one of the Doppler shift amount and the code sequence is different between a plurality of the combinations. A number of multiplexing by the code sequence corresponding to a first Doppler shift amount is different from a number of multiplexing by the code sequence corresponding to a second Doppler shift amount.

Abstract: Each of the plurality of transmission antenna groups includes a plurality of transmission antennas that are disposed at second intervals in a first direction, and are disposed at fourth intervals each of which is an interval of an integral multiple of a third interval in a second direction. Each of the plurality of reception antenna groups includes a plurality of reception antennas that are disposed at fifth intervals in the first direction, and are disposed at sixth intervals each of which is an interval of an integral multiple of the third interval in the second direction. The difference between the second interval and the fifth interval is the first interval, and the difference between the fourth interval and the sixth interval is the third interval.

Abstract: A plurality of transmission antennas include Nt1 transmission antennas arranged in a first direction and Nt2 transmission antennas arranged in a second direction orthogonal to the first direction, a plurality of reception antennas include Na1 reception antennas arranged in the first direction and Na2 reception antennas arranged in the second direction. In the first direction, an inter-element space between any two of the Nt1 transmission antennas and an inter-element space between any two of the Na1 reception antennas are each a value which is a product of a first space and an integer and are all values different from each other, and in the second direction, an inter-element space between any two of the Nt2 transmission antennas and an inter-element space between any two of the Na2 reception antennas are each a value which is a product of a second space and an integer and are all values different from each other.

Abstract: A radar apparatus includes a radar transmitter that transmits a radar signal in a predetermined transmission cycle and a radar receiver that receives a reflection wave signal being a reflection of the radar signal on a target. The radar transmitter includes a phase rotation controller that randomly varies a pattern of a phase rotation every period corresponding to a plurality of transmission cycles, the pattern being to be applied to the radar signal within a period, and a transmission phase rotator that assigns a first phase rotation to the radar signal in accordance with the pattern. The radar receiver includes a reception phase rotator that assigns a second phase rotation in a direction opposite to a direction of the first phase rotation to the reflection wave signal in accordance with the pattern.