Method and apparatus using fast electronic switching for multi-channelizing a single-channel radar system

• US 7,557,747 B1
• Filed: 04/05/2006
• Issued: 07/07/2009
• Est. Priority Date: 04/13/2005
• Status: Expired due to Fees

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Morgan, Donald G., Ransom, Paul E. Jr., Smith, Jerry Rosson Jr.
• Primary Examiner(s): ALSOMIRI, ISAM A
• Application Number:
  US11/398,233
• Time in Patent Office: 1,189 Days
• Field of Search: 342 73- 74, 342444-445, 342/465, 343/824
• US Class Current: 342/74
• CPC Class Codes: G01S 13/9058 Bistatic or multistatic SAR
• CPC Class Codes: G01S 2013/0254 Active array antenna
• CPC Class Codes: G01S 7/024 using polarisation effects in waveguides H01P1/165; for aerials H01Q, e.g. H01Q15/22, H01Q15/24, H01Q19/195
• CPC Class Codes: G01S 7/288 Coherent receivers
• CPC Class Codes: H01Q 3/24 varying the orientation by switching energy from one active radiating element to another, e.g. for beam switching

Abstract

According to typical practice of an inventive radar system, a switching device is capable of activating a receiver array one at a time so that when a receiver is activated the remaining receivers are inactivated. A switch control circuit is pre-programmed with control logic that is based on the counting of radio pulses that are emitted by a signal generator (for transmission by a transmitter). The control logic dictates, via the switching device, the rapid sequential cycling through of the arrayed receivers so that each receiver is activated for the same prescribed period of time, which corresponds to a pre-programmed number N of emitted radio pulses wherein N=[the number of frequencies in the wave table]×[the number of pulse integrations in the wave table]×[1 polarization or 2 polarizations]. Radio pulse input from the receivers is interleaved in a manner associable with individual receivers.

Claims

1. An electromagnetic receiver array system comprising:

a plurality of receiver antennae for receiving electromagnetic pulses;

a switching device associated with said receiver antennae and capable of causing each said receiver antenna to be in one of an active state and an inactive state, wherein when a said receiver antenna is in said active state said receiver antenna is receptive to electromagnetic pulses, and wherein when a said receiver antenna is in said inactive state said receiver is not receptive to electromagnetic pulses;

a switch control circuit associated with said switching device and capable of controlling said switching device so that at any given time one said receiver antenna is in said active state and every other said receiver antenna is in said inactive state, and so that said receiver antennae are sequentially cycled through said active states; and

means for emitting electromagnetic pulses, said means for emitting electromagnetic pulses being associated with said switch control circuit;

wherein each said receiver antenna is in said active state for a duration commensurate with a selected number of emitted electromagnetic pulses, wherein each said receiver antenna is in said active state for the same said duration, wherein said emitted electromagnetic pulses are characterized by a wave table, and wherein said switch control circuit is characterized by logic whereby each said duration equals the product of the number of frequencies in said wave table times the number of pulse integrations in said wave table.

2. The electromagnetic receiver array system of claim 1, wherein said switch control circuit is capable of controlling said switching apparatus so that said receiver antennae are sequentially cycled through said active states at least twice.

3. The electromagnetic receiver array system of claim 1, further comprising a data storage device associated with said receiver antennae and capable of storing information pertaining to electromagnetic pulses received by said receiver antennae, said storing being effected in an interleaved manner so that each portion of said information corresponds with receipt of electromagnetic pulses by a particular said receiver antenna.

4. The electromagnetic receiver array system of claim 1, wherein said duration is no less than 800 nanoseconds.

5. An electromagnetic receiver array of system comprising:

a plurality of receiver antennae for receiving electromagnetic pulses;

a switching device associated with said receiver antennae and capable of causing each said receiver antenna to be in one of an active state and an inactive state, wherein when a said receiver antenna is in said active state said receiver antenna is receptive to electromagnetic pulses, and wherein when a said receiver antenna is in said inactive state said receiver is not receptive to electromagnetic pulses;

a switch control circuit associated with said switching device and capable of controlling said switching device so that at any given time one said receiver antenna is in said active state and every other said receiver antenna is in said inactive state, and so that said receiver antennae are sequentially cycled through said active states; and

means for emitting electromagnetic pulses, said means for emitting electromagnetic pulses being associated with said switch control circuit;

wherein;

each said receiver antenna is in said active state for a duration commensurate with a selected number of emitted electromagnetic pulses, each said receiver antenna is in said active state for the same said duration;

said emitted electromagnetic pulses are characterized by a wave table;

said switch control circuit is characterized by logic whereby each said duration equals the product of the number of frequencies in said wave table times the number of pulse integrations in said wave table times the number of polarizations;

said number of polarizations is either of one or two;

said number of polarizations of one represents either of horizontal polarization and vertical polarization;

said number of polarizations of two represents both of horizontal polarization and vertical polarization.

6. The electromagnetic receiver array system of claim 5, further comprising a data storage device associated with said receiver antennae and capable of storing information pertaining to electromagnetic pulses received by said receiver antennae, said storing being effected in an interleaved manner so that each portion of said information corresponds with receipt of electromagnetic pulses by a particular said receiver antenna at a particular time.

7. The electromagnetic receiver array system of claim 5, further comprising at least one transmitter antenna for transmitting said emitted electromagnetic pulses, wherein at least one transmitted said emitted electromagnetic pulse is received by at least one said receiver antenna.

8. A method for using plural receiver antennae, the method comprising:

associating a switching device with plural receiver antennae, said switching device being capable of causing each said receiver antenna to be in one of an active state and an inactive state, wherein when a said receiver antenna is in said active state said receiver antenna is receptive to electromagnetic signals, and wherein when a said receive antenna is in said inactive state said receiver is not receptive to electromagnetic signals;

associating a switch control circuit with said switching device, said switch control circuit being capable of controlling said switching apparatus so that at any given time one said receiver antenna is in said active state and every other said receiver antenna is in said inactive state, and so that said receiver antennae are sequentially cycled through said active states; and

associating said switch control circuit with means for emitting electromagnetic signals;

wherein each said receiver antenna is in said active state for a duration commensurate with a selected number of electromagnetic signals emitted from a transmitter antenna, wherein emitted electromagnetic signals are characterized by a wave table, and wherein each said duration equals the product of the number of frequencies in said wave table times the number of signal integrations in said wave table.

9. The method for using plural receiver antennae as recited in claim 8, said method further comprising storing data pertaining to electromagnetic signals received by said receiver antennae, said storing being effected in an interleaved manner so that each portion of said data corresponds with receipt of electromagnetic signals by a particular said receiver antenna.

10. The method for using plural receiver antennae as recited in claim 9, said storing being effected in an interleaved manner so that each portion of said data corresponds with receipt of electromagnetic signals by a particular said receiver antenna at a particular time.

11. The method for using plural receiver antennae as recited in claim 8, wherein said duration is at least 800 nanoseconds, and wherein each said receiver antenna is in said active state for the same said duration.

12. A method for using plural receiver antennae, the method comprising:

associating a switching device with plural receiver antennae, said switching device being capable of causing each said receiver antenna to be in one of an active state and an inactive state, wherein when a said receiver antenna is in said active state said receiver antenna is receptive to electromagnetic signals, wherein when a said receiver antenna is in said inactive state said receiver is not receptive to electromagnetic signals;

associating a switch control circuit with said switching device, said switch control circuit being capable of controlling said switching apparatus so that at any given time one said receiver antenna is in said active state and every other said receiver antenna is in said inactive state, and so that said receiver antennae are sequentially cycled through said active states; and

associating said switch control circuit with means for emitting electromagnetic signals;

wherein;

each said receiver antenna is in said active state for a duration commensurate with a selected number of electromagnetic signals emitted from a transmitter antenna;

said emitted electromagnetic signals are characterized by a wave table;

each said duration equals the product of the number of frequencies in said wave table times the number of signal pulse integrations in said wave table times the number of polarizations;

said number of polarizations is either of one and two;

said number of polarizations of one represents either of horizontal polarization and vertical polarization;

said number of polarizations of two represents both of horizontal polarization and vertical polarization.