04873530 is referenced by 37 patents and cites 74 patents.

In a ratio-mediated keyless entry system for an automotive vehicle, two vehicle-mounted antennae, lying in mutually perpendicular planes are used to receive radio signals from a portable, manually operable transmitter. When the transmitter is left in the passenger compartment and then the doors are locked, the system generates an alarm to notify the driver of the fact. On antenna completely encircles the passenger compartment. Encircling the passenger compartment with one of the vehicle-mounted antennae ensures that wherever the transmitter is left in the passenger compartment, its presence will be detected no matter how limited the transmitter's range.

Title
Antenna device in automotive keyless entry system
Application Number
6/912518
Publication Number
4873530
Application Date
September 29, 1986
Publication Date
October 10, 1989
Inventor
Takahisa Tomoda
Sagamihara
JP
Kenichi Mitamura
Fujisawa
JP
Kinichiro Nakano
Zama
JP
Mikio Takeuchi
Zama
JP
Agent
Foley & Lardner Schwartz Jeffery Schwaab Mack Blumenthal & Evans
Assignee
Nissan Motor
JP
IPC
H01Q 1/32
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