公开(公告)号：US20220276366A1

公开(公告)日：2022-09-01

申请号：US17637662

申请日：2019-08-23

申请人： Nippon Telegraph and Telephone Corporation

发明人： Tatsuya IIZUKA ,  Fumihiko ISHIYAMA ,  Yohei TORIUMI ,  Jun KATO

IPC分类号： G01S13/34 ,  G01S7/35 ,  G01S13/38

摘要： A radar apparatus (1) of the present embodiment includes a transmitting unit (12) that transmits a frequency chirp signal whose frequency linearly changes with time, a receiving unit (13) that receives a reflected wave that is the frequency chirp signal reflected by an object, a mixer (14) that mixes the transmitted frequency chirp signal and the received reflected wave to obtain a beat signal, a frequency estimation unit (15) that estimates a frequency of the beat signal, and a distance estimation unit (16) that estimates a distance to the object based on the frequency of the beat signal. The frequency estimation unit (15) calculates an autoregressive coefficient of an autoregressive model from a sequence of discrete signal values of the beat signal and estimates the frequency of the beat signal using a base frequency that is based on a pole of the autoregressive model.

公开(公告)号：US20230194691A1

公开(公告)日：2023-06-22

申请号：US17925680

申请日：2020-05-29

申请人： Nippon Telegraph and Telephone Corporation

发明人： Tatsuya IIZUKA ,  Yohei TORIUMI ,  Fumihiko ISHIYAMA ,  Jun KATO

IPC分类号： G01S13/536 ,  G01S7/35 ,  G01S13/42 ,  G01S7/41

CPC分类号： G01S13/536 ,  G01S7/354 ,  G01S13/42 ,  G01S7/415

摘要： A radar apparatus includes: a transmission unit that transmits a chirp signal; a reception unit that receives a reflected signal that is the chirp signal reflected by a scatterer; and a pole calculation unit that calculates a beat signal based on the chirp signal and the reflected signal and calculates a pole of the beat signal by eigenvalue decomposition of an autocorrelation matrix of the beat signal. The radar apparatus further includes: a complex amplitude calculation unit that calculates a complex amplitude corresponding to the pole by using a least squares method between a basis waveform corresponding to the pole and the beat signal; a distance calculation unit that calculates a distance to the scatterer based on the beat signal; and an intensity calculation unit that calculates an intensity of the reflected signal based on the complex amplitude.

公开(公告)号：US20210408693A1

公开(公告)日：2021-12-30

申请号：US17289835

申请日：2019-10-16

申请人： Nippon Telegraph and Telephone Corporation

发明人： Go ITAMI ,  Yohei TORIUMI ,  Jun KATO

IPC分类号： H01Q15/00 ,  H01Q15/14 ,  G06F30/39

摘要： To accurately estimate frequency characteristics from structural parameters of a frequency selective surface. A frequency selective surface design apparatus includes an LC generation unit 20 that receives an input of a structural parameter, and generates an inductance L and a capacitance C of a unit cell, a corrected resonance point calculation unit 30 that receives the number n of times of calculation input from an outside, the inductance L, and the capacitance C, models a correction circuit by using a circuit in which a virtual capacitance is connected in parallel via a transmission line to each distribution inductance obtained by division of the inductance L by the calculation number n and the transmission line is terminated at the capacitance C, and calculates a corrected resonant frequency fC from the impedance of the correction circuit, and a characteristic calculation unit 40 that receives inputs of the inductance L, the capacitance C, and the corrected resonant frequency fC, calculates a pre-correction resonant frequency from the inductance L and the capacitance C, obtains a correction coefficient by dividing the corrected resonant frequency fC by the pre-correction resonant frequency, and calculates a corrected return loss and a corrected insertion loss.