US 12,320,912 B2
Positioning system
Kenichirou Sanji, Nisshin (JP); Nobuyasu Okabe, Kariya (JP); Masakazu Ikeda, Nisshin (JP); and Yuuji Kakuya, Nisshin (JP)
Assigned to DENSO CORPORATION, Kariya (JP)
Filed by DENSO CORPORATION, Kariya (JP)
Filed on Oct. 22, 2021, as Appl. No. 17/508,107.
Application 17/508,107 is a continuation of application No. PCT/JP2020/010091, filed on Mar. 9, 2020.
Claims priority of application No. 2019-085381 (JP), filed on Apr. 26, 2019.
Prior Publication US 2022/0043100 A1, Feb. 10, 2022
Int. Cl. G01S 5/02 (2010.01); B60R 25/01 (2013.01); B60R 25/24 (2013.01); G01S 5/00 (2006.01); H01Q 1/32 (2006.01); H01Q 9/04 (2006.01); H01Q 21/24 (2006.01)
CPC G01S 5/0284 (2013.01) [G01S 5/012 (2020.05); H01Q 1/3241 (2013.01); H01Q 9/0421 (2013.01); H01Q 21/24 (2013.01); B60R 25/01 (2013.01); B60R 25/245 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A positioning system comprising:
a vehicle exterior communication device configured to be disposed at an outer surface portion of a vehicle being at least one of a side surface portion of the vehicle or a rear side surface portion of the vehicle, and including an antenna configured to receive a wireless signal transmitted from a portable terminal, the wireless signal being a radio wave of 1 GHz or higher; and
a positioning device configured to determine whether or not the portable terminal exists at an exterior operating area being a region outside a vehicle compartment within a predetermined operating distance from the vehicle, based on a reception status of the wireless signal received by the vehicle exterior communication device from the portable terminal,
wherein the antenna is further configured to radiate a main polarized wave in a predetermined direction and radiate a cross-polarized wave in a direction perpendicular to a radiating direction of the main polarized wave,
wherein the vehicle exterior communication device is further configured to be disposed in a posture such that:
the main polarized wave is radiated in a direction along the outer surface portion at which the vehicle exterior communication device is attached; and
the cross-polarized wave is radiated in a direction perpendicular to the outer surface portion,
wherein the antenna includes:
a ground plate made of a conductor with a flat plate shape;
only one opposing conductive plate made of another conductor with a flat plate shape, and configured to be disposed to space apart from the ground plate with a predetermined distance; and
a short-circuit portion configured to be disposed at a central region of the opposing conductive plate and electrically connect the opposing conductive plate and the ground plate,
wherein a virtual line located on the ground plate is parallel to the ground plate and passes through a center of the ground plate,
wherein a center of the only one opposing conductive plate is deviated from the center of the ground plate along the virtual line, as viewed in a direction perpendicular to the ground plate,
wherein the antenna is further configured to generate parallel resonance in a communication frequency as a frequency for the wireless communication by adopting an electrostatic capacitance between the opposing conductive plate and the ground plate and an inductance in the short-circuit portion,
wherein the vehicle exterior communication device is further configured to be attached at the outer surface portion in a posture such that the ground plate faces the outer surface portion,
wherein the center of the only one opposing conductive plate is deviated from the center of the ground plate with a predetermined distance along the virtual line, and
wherein λ denotes a wavelength of the radio wave, and the predetermined distance is set to a value in a range of 0.08λ to 0.25λ.