Antenna device and signal processing method

Patent metadata

Field	Value
Publication number	US-9843109-B2
Application number	US-201415025195-A
Country	US
Kind code	B2
Filing date	Jul 14, 2014
Priority date	Sep 27, 2013
Publication date	Dec 12, 2017
Grant date	Dec 12, 2017

Abstract

An antenna device includes a plurality of antenna elements respectively configured to receive incident waves coming from an object, a modulating unit respectively configured to modulates a first received signal of the incident waves output from the antenna elements into a second received signal, the second received signals having a plurality of different frequencies and phases corresponding to polarization directions of the received incident waves, a synthesizing unit configured to synthesize the plurality of second received signals and generates a synthetic signal, a signal processing unit, configured to perform predetermined signal processing on the synthetic signal, and an extracting unit configured to extract third received signals for each frequency and each phase from the synthetic signal on which has been performed the predetermined signal processing.

First claim

The invention claimed is:

1. An antenna device comprising:
a plurality of antenna elements respectively configured to receive incident waves coming from an object and output a first received signal on a basis of received incident waves, the plurality of antenna elements including at least a first antenna element that receives incident waves of a predetermined polarization direction and a second antenna element that receives incident waves of a polarization direction different from the incident waves received by the first antenna element;
a plurality of modulating units respectively configured to modulate the first received signal output from a respective antenna element into a second received signal, such that the second received signal has a frequency corresponding to a position of the respective antenna element in the antenna device and has a phase corresponding to the polarization directions of the incident waves received by the respective antenna element, so that a plurality of second received signals have a plurality of different frequencies corresponding to the respective position of the respective antenna element in the antenna device and have phases corresponding to the polarization directions of the incident waves received by the plurality of antenna elements;
a synthesizing unit configured to synthesize the plurality of second received signals respectively modulated by the plurality of modulating units so as to generate one synthetic signal;
a signal processing unit configured to perform signal processing on the synthetic signal; and
an extracting unit configured to extract third received signals from the synthetic signal on which has been performed the signal processing, each of the third received signals having a frequency and a phase equal to the frequency and the phase of each of the plurality of second received signals modulated by the plurality of modulating units.

2. The antenna device according to claim 1 , wherein:
the first antenna element mainly receives the incident waves of a horizontally polarized component, and
the second antenna element mainly receives the incident waves of a vertically polarized component.

3. The antenna device according to claim 1 , further comprising:
an array antenna in which the plurality of antenna elements is arranged in a two dimensional form, wherein the plurality of modulating units respectively modulates the first received signal output from the respective antenna element into the second received signal, such that the second received signal has a frequency corresponding to a position of the respective antenna element on the array antenna.

4. The antenna device according to claim 3 , wherein the modulating unit extracts a difference between a frequency allocated to a row in which the respective antenna element is arranged and a frequency allocated to a column in which the respective antenna element is arranged as the frequency corresponding to the position of the respective antenna element on the array antenna.

5. The antenna device according to claim 3 , wherein the plurality of modulating units modulates each first received signal output from the plurality of antenna elements corresponding to a predetermined reception range of the array antenna into second received signals having the same frequency and the same phase.

6. The antenna device according to claim 3 , wherein the plurality of modulating units modulates each first received signal output from the antenna elements consecutively arranged in an array direction corresponding to a vertical direction of a reception range of the array antenna into each second received signal having the same frequency and the same phase.

7. The antenna device according to claim 1 , wherein the plurality of modulating units modulate each first received signal into second received signals having frequencies within a specific frequency band different from a frequency band of frequencies before modulating.

8. The antenna device according to claim 7 , wherein the specific frequency band is decided on a basis of a conversion time period of the second received signal at which the second received signal is converted from an analog signal to a digital signal and/or a receiving time period of the incident waves.

9. The antenna device according to claim 1 , wherein the extracting unit extracts the third received signals from the synthetic signal by performing phase synchronization on the synthetic signal using phases of the plurality of second received signals modulated by the modulating units.

10. The antenna device according to claim 1 , further comprising:
a control unit configured to perform a modulation control process for controlling the plurality of modulating units so that the plurality of modulating units respectively modulate the first received signals output from each of the plurality of antenna elements into the second received signals having the same frequency.

11. The antenna device according to claim 10 , wherein the control unit is further configured to:
detect power of the first received signal output from each of the plurality of antenna elements;
determine a degree of influence of a noise on the first received signal output from each of the plurality of antenna elements on a basis of an error of the power; and
perform the modulation control process when the degree of the influence of the noise is determined to be equal to a predetermined value or more.

12. The antenna device according to claim 10 , further comprising:
an acquiring unit configured to acquire a moving speed of a moving object equipped with the antenna device,
wherein the control unit modulates the first received signals output from the plurality of antenna elements so that a slower the moving speed of the moving object is, a greater a number of the first received signals that are modulated into the second received signals having the same frequency, compared to when the moving speed of the moving object is fast.

13. The antenna device according to claim 1 , further comprising:
a detecting unit configured to detect the object on a basis of the first received signal,
wherein the plurality of modulating units modulates only the first received signal on the basis of a horizontally polarized component until the detecting unit detects the object using the first received signal of the horizontally polarized component,
when the detecting unit detects the object using the first received signal on the basis of the horizontal polarized component, the plurality of modulating units modulates the first received signal of the horizontal polarized component and the first received signal of a vertically polarized component.

14. The antenna device according to claim 1 , further comprising:
a transmitter configured to transmit transmission waves to the object,
wherein the antenna element receives electromagnetic waves as the incident waves, the electromagnetic waves coming as the transmission waves transmitted by the transmitter and reflected by the object.

15. An antenna device comprising:
a plurality of first antenna elements respectively configured to receive first incident waves of a predetermined polarization direction coming from an object and respectively configured to output a first received signal on a basis of received first incident waves;
a plurality of second antenna elements respectively configured to receive second incident waves of a polarization direction different from the polarization direction of the first incident waves and respectively configured to output a second received signal on a basis of received second incident waves;
a plural

Assignees

• Nissan Motor

Inventors

• Nakamura Mitsunori
• Satoh Hiroshi
• Nishioka Shinichi
• Nishiuchi Hidekazu

Classifications

• G01S7/03

  Details of HF subsystems specially adapted therefor, e.g. common to transmitter and receiver · CPC title

• G01S7/352

  Receivers · CPC title

• G01S7/024

  using polarisation effects (in waveguides H01P1/165; for aerials H01Q, e.g. H01Q15/22, H01Q15/24, H01Q19/195) · CPC title

• G01S13/931

  of land vehicles · CPC title

• H01Q3/22

  varying the orientation in accordance with variation of frequency of radiated wave · CPC title