Radar transponder

• US 5,724,045 A
• Filed: 09/20/1995
• Issued: 03/03/1998
• Est. Priority Date: 09/22/1994
• Status: Expired due to Term

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Kawakami, Youichi
• Primary Examiner(s): Blum, Theodore M.
• Application Number:
  US08/531,072
• Time in Patent Office: 895 Days
• Field of Search: 342/357, 364/449.7, 343/881, 343/882
• US Class Current: 342/357.55
• CPC Class Codes: H01Q 1/084 Pivotable antennas
• CPC Class Codes: H01Q 1/34 Adaptation for use in or on ships, submarines, buoys or torpedoes for subaqueous use H01Q1/04
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00

Abstract

A multi-functional radar transponder functions as SART in an emergency condition and as monitor, GPS receiver and VHF transceiver for non-emergency conditions. The radar transponder has an antenna including a SART antenna, a GPS antenna and a Marine VHF antenna. The radar transponder further includes a SART circuit with a monitor output device for monitoring a radar signal, and transfer switches for transferring a monitor process in a normal mode to a responding process in an emergency mode, and vice versa. The GPS antenna closes to a position parallel to the SART antenna in the normal mode and opens vertically against the SART antenna in the emergency mode. The Marine VHF antenna locks the GPS antenna together with the SART antenna for preventing a false emergency response in the normal mode and unlocks the SART antenna for an emergency response in the emergency mode.

Claims

1. A multi-functional radar transponder having a Global Positioning System (GPS) receiver and equipped for being mounted in a ship comprising:

means for monitoring radar signals from other ships in a normal mode and for receiving and transmitting marine disaster signals in an emergency mode;

a multi-functional antenna structure comprising;

a first antenna for receiving the radar signals from other ships in the normal mode and for receiving and transmitting marine disaster signals in the emergency mode; and

a second antenna for receiving GPS signals mounted to be positioned adjacent to and to be folded out to a position extending at an angle of about 90 degrees to the first antenna in the emergency mode; and

a first switch operated with the positioning of the second antenna from the normal mode to the emergency mode for disenabling the transmission of the marine disaster signals in the normal mode and for enabling the transmission of the marine disaster signals in the emergency mode.

2. The radar transponder according to claim 1, further comprising:

a VHF antenna movable between two positions for transmitting and receiving VHF radio signals, wherein the VHF antenna holds the second antenna together with the first antenna in a first of the two positions corresponding to the normal mode, and frees the second antenna in a second of the two positions corresponding to the emergency mode.

3. The radar transponder according to claim 2, wherein the VHF antenna includes a sliding structure for enabling sliding movement of the VHF antenna between the first and second positions.

4. The radar transponder according to claim 2, wherein the VHF antenna includes a folding structure for enabling folding movement of the VHF antenna between the first and second positions.

5. The radar transponder according to claim 1, further comprising:

a monitor operated by the first switch, for monitoring received signals from another ship through the first antenna in the normal mode.

6. The radar transponder according to claim 1, further comprising:

a monitor for monitoring received signals from another ship through the first antenna.

7. The radar transponder according to claim 5 or 6, wherein the monitor is a speaker.

8. The radar transponder according to claim 5, wherein the first switch is a micro-switch.

9. The radar transponder according to claim 5, wherein the first switch is a reed-switch.

10. A multi-functional radar transponder having a Global Positioning System (GPS) receiver and equipped for being mounted in a ship comprising:

a multi-functional antenna structure comprising;

a first antenna for monitoring radar signals from other ships in a normal mode and for receiving and transmitting marine disaster signals in an emergency mode;

a second antenna for receiving GPS signals mounted to be positioned adjacent to and parallel with the first antenna in the normal mode and to be folded out at an angle of about 90 degrees to the first antenna in the emergency mode; and

a switch operated by the folding out of the second antenna to the emergency mode for preventing power from being supplied to the radar transponder in the normal mode and for supplying power to the radar transponder in the emergency mode.

11. A method of operating a multi-functional radar transponder and Global Positioning System (GPS) receiver operable in normal and emergency modes and having a first antenna operable with the radar transponder for receiving GPS signals in a normal mode, a second antenna foldable between positions against and away from the first antenna, said second antenna also for receiving GPS signals, and a switch operable with the folding of the second antenna between the positions for selecting one of a radar monitoring and a transmitting marine disaster signal function, comprising the steps of:

positioning the second antenna in a horizontal position substantially parallel to the earth'"'"'s surface and receiving GPS signals from the vertical direction in a normal mode; and

positioning the first antenna in a vertical position substantially perpendicular to the earth'"'"'s surface and monitoring radar signals from other ships also in a normal mode.

12. A method of operating a multi-functional radar transponder and Global Positioning System (GPS) receiver operable in normal and emergency modes and having a first antenna operable with the radar transponder for receiving GPS signals in a normal mode, a second antenna foldable between positions against and away from the first antenna, said second antenna also for receiving GPS signals, and a switch operable with the folding of the second antenna between the positions for selecting one of a radar monitoring and a transmitting marine disaster signal function, comprising the steps of:

folding up the second antenna at an angle of about 90 degrees with respect to the first antenna for selecting said transmitting marine disaster signal function in an emergency mode;

receiving a GPS signal by the second antenna in emergency mode if needed, wherein the first antenna is set horizontally; and

receiving and transmitting a marine disaster signal by the first antenna set horizontally in an emergency mode.