Low-loss, fault-tolerant antenna interface unit

• US 6,018,644 A
• Filed: 01/28/1997
• Issued: 01/25/2000
• Est. Priority Date: 01/28/1997
• Status: Expired due to Term

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: Northrop Grumman Corporation
• Inventors: Minarik, Ronald W.
• Primary Examiner(s): Urban, Edward F.
• Assistant Examiner(s): Nguyen, Thuan T.
• Application Number:
  US08/789,770
• Time in Patent Office: 1,092 Days
• Field of Search: 455/78, 455/82, 455/83, 455/103, 455/129, 455/127, 455/561, 455/562, 455/8, 455/9, 455/20
• US Class Current: 455/82
• CPC Class Codes: H01Q 3/267 Phased-array testing or checking devices
• CPC Class Codes: H04B 1/0466 Fault detection or indication H04B1/0483 takes precedence
• CPC Class Codes: H04B 1/44 Transmit/receive switching

Abstract

An antenna interface unit (AIU) for providing low power loss, fault tolerant connectivity between multiple transmitters and an antenna, and between multiple receivers and the antenna. The antenna interface unit also eliminates single point failures in a transmit/receive (T/R) mechanism. The antenna interface unit includes (a) a power combiner/splitter connectable to the antenna; a receive channel connected to the power combiner/splitter; and a transmit channel connected to the power combiner/splitter. The transmit channel is a different channel from the receive channel. The receivers are connectable to the antenna via the receive channel and through the power combiner/splitter. The transmitters are connectable to the antenna via the transmit channel and through the power combiner/splitter. Different variations of the receive channel and the transmit channel are provided by using different combinations of power combiners and power splitters.

Claims

1. A radio system including an antenna interface unit providing fault-tolerant connectivity between a plurality of receivers and a plurality of transmitters to an antenna, the antenna interface unit comprising:

a substantially zero failure rate power combiner/splitter including a plurality of inputs and an output, said output being connected to the antenna;

a plurality of fault tolerant transmit/receive (T/R) circuit elements connected to said inputs of the power combiner splitter;

a plurality of receive channels corresponding to the plurality of receivers connected to the power combiner/splitter via said T/R circuit elements, the receivers thereby being connectable to the antenna via respective receive channels of said plurality of receive channels, through the substantially zero failure rate power combiner/splitter, and the fault tolerant T/R circuit elements; and

a plurality of transmit channels corresponding to the plurality of transmitters also connected to the power combiner/splitter via said T/R circuit elements, said transmit channels being different channels from each of the receive channels, the transmitters being connectable to the antenna via respective transmit channels of said plurality of transmit channels, through the substantially zero failure rate RF power combiner/splitter and the fault tolerant switching means.

2. An antenna interface unit as in claim 1, wherein the fault tolerant T/R circuit elements comprise transmit/receive (T/R) switches, duplexers or circulators.

3. An antenna interface unit as in claim 1 and further comprising:

a substantially zero failure rate transmit signal power combiner connected to said plurality of transmitters, receiving signals transmitted by said transmitters and producing a combined transmit signal;

a substantially zero failure rate transmit signal power splitter connected to the transmit signal power combiner, receiving the combined transmit signal produced thereby and producing a plurality of split transmit signals at least equal in number to said plurality of transmit channels; and

,

signal summers connected between said transmit signal power splitter and said fault tolerant T/R circuit elements and producing summed signals thereby, said summed signals being thereafter fed to said switching means.

4. An antenna interface unit as in claim 3 wherein the plurality of split transmit signals is at least twice the number of transmit channels and applied in pairs of split transmit signals to said signal summers.

5. An antenna interface unit as in claim 4 and wherein the combined transmit signal produced by the transmit signal power combiner is phase and amplitude matched with a combined transmit signal produced by and appearing at the output of said power combiner/splitter.

6. A fault tolerant antenna interface unit for selectively connecting multiple RF receivers and multiple RF transmitters to a common antenna, comprising:

a substantially zero failure rate unitary RF power combiner/splitter having a plurality of inputs and an output connectable to the antenna;

a plurality of transmit/receive channels connected to said plurality of inputs of the unitary RF power combiner/splitter;

a respective plurality of fault tolerant circuit means connected to the plurality of transmit/receive channels for coupling transmit RF signals and receive RF signal to and from said unitary RF power combiner/splitter;

a plurality of receive channels, respectively corresponding to a respective plurality of RF receivers connected to said fault tolerant circuit means for coupling, said RF receivers thereby being connectable to the antenna via said plurality of transmit/receive channels and through said unitary RF power combiner/splitter;

a plurality of transmit channels, respectively corresponding to a respective plurality of RF transmitters connected to said fault tolerant circuit means for coupling, and including,

a substantially zero failure rate transmit signal RF power combiner including a plurality of inputs respectively connected to the transmitters, receiving signals transmitted by said transmitters via said plurality of inputs and producing a corresponding combined transmit signal,

a plurality of split RF transmit signal paths,

a substantially zero failure rate transmit signal RF power splitter connected between the transmit signal RF power combiner and the split RF transmit signal paths, receiving the combined transmit signal produced by the transmit signal RF power combiner and producing split transmit signals for said split RF transmit signal paths,

a plurality of summed RF transmit signal paths equal in number to the number of transmit channels,

a plurality of RF transmit signal summers equal in number to said summed RF transmit signal paths connected between the split RF transmit signal paths and the summed RF transmit signal paths, and producing and feeding summed RF transmit signals to the circuit means for coupling and then to said unitary RF power combiner/splitter via said summed RF transmit signal paths and said transmit/receive channels, respectively.

7. A fault tolerant antenna interface unit as in claim 6 and further comprising:

another substantially zero failure rate transmit signal RF signal power combiner connected to said plurality of signal summers and producing another combined transmit signal; and

another substantially zero failure rate transmit signal RF power splitter connected between said fault tolerant circuit means for coupling and said another transmit RF signal power combiner;

said substantially zero failure rate transmit signal RF power splitter, said split RF transmit signal paths, said signal summers, and said another substantially zero failure rate transmit signal RF power combiner comprising components of a fault tolerant power amplifier.

8. An antenna interface unit as in claim 7, wherein when said transmitters are transmitting, said another combined transmit signal produced by said another transmit signal RF power combiner connected to said signal summers is phase and amplitude matched with said combined transmit signal produced by said transmit signal RF power combiner connected to the transmitters.

9. An antenna interface unit as in claim 8, wherein when said transmitters are transmitting, said another combined transmit signal is phase and amplitude matched with transmit signals output to said antenna by unitary RF power combiner/splitter.

10. An antenna interface unit according to claim 6, and further comprising:

a substantially zero failure rate receive signal RF power combiner connected to said receive channels and being responsive to split receive signals produced by said unitary RF power combiner/splitter, when receivers are receiving, for producing a combined receive RF signal at an output terminal thereof.

11. An antenna interface unit according to claim 10 wherein said combined receive signal at said output terminal is phase and amplitude matched with the split receive signals produced by said unitary RF power combiner/splitter.

12. An antenna interface unit according to claim 10 and additionally including a substantially zero failure rate receive signal RF power splitter located externally of the antenna interface unit and being connected to said output terminal of said substantially zero failure rate receive RF signal power combiner for producing individual receive signals which are respectively connected to said plurality of receivers.

13. An antenna interface unit as in claim 6 and further comprising:

another substantially zero failure rate transmit signal RF power combiner connected to said plurality of signal summers and producing an intermediate combined transmit signal;

another substantially zero failure rate transmit signal RF power splitter connected between said another transmit signal power combiner and said circuit means for coupling for producing a plurality of intermediate split transmit signals coupled to said unitary RF power combiner during a transmit mode of operation;

a substantially zero failure rate receive signal RF power combiner, connected to said unitary RF power combiner/splitter via said circuit means for coupling, for producing an intermediate combined receive during a receive mode of operation; and

a substantially zero failure rate receive signal RF power splitter connected to said receive signal RF power combiner for producing individual receive signal respectively connected to said plurality of receivers.

14. An antenna interface unit as in claim 6 wherein said fault tolerant circuit means for coupling the transmit and receive signals to and from the antenna via said power combiner/splitter includes T/R switches, duplexers and circulators.

15. An antenna interface unit as in claim 6 wherein each receive channel includes a band pass filter, an automatic gain control circuit and a low noise amplifier.

16. A fault tolerant power amplifier having fault tolerant T/R switching in an antenna interface unit which connects multiple receivers and multiple transmitters to an antenna, the receivers being connected to the amplifier through respectively corresponding receive signal channels and the transmitter being connected to the amplifier through a substantially zero failure rate transmit signal RF power combiner, the amplifier comprising:

a plurality of common transmit/receive signal channels at least equal in number to the number of receive signal channels;

a plurality of transmit channels;

a substantially zero failure rate transmit signal RF power splitter connected to the transmit signal RF power combiner, receiving a combined transmit signal from said RF power combiner and producing a plurality of split transmit signals which are coupled to said plurality of transmit channels;

a substantially zero failure rate RF power combiner/splitter connectable to the antenna and said common input/output signal channels, and

respective fault tolerant T/R switching means equal in number to the number of receive signal channels and the number of said common input/output signal channels, each said fault tolerant T/R switching means being connected to a respective receive signal channel, a respective common input/output signal channel and a respective transmit signal channel, and selectively allowing either the corresponding receive signal channel to receive signals from the antenna via the RF power combiner/splitter or the corresponding transmit signal channel to transmit signals to the antenna via the RF power combiner/splitter.

17. A fault tolerant power amplifier as in claim 16 and further comprising:

a plurality of transmit signal sub-channels greater in number than said plurality of transmit signal channels located between the transmit signal RF power splitter and the transmit channels for coupling the split transmit signals to the transmit channels via signal summers, and

a plurality of signal summers, equal in number to the transmit signal channels and the receive signal channels, connected between said transmit signal channels and the transmit signal sub-channels and receiving the split transmit signals from the transmit sub-channels and producing summed transmit signals applied to the transmit channels, said fault tolerant T/R switching means allowing either the corresponding receive channel to receive RF signals from the antenna via the RF power combiner/splitter or the corresponding transmit channel to transmit RF signals to the antenna via the RF power combiner/splitter.

18. An amplifier as in claim 17 wherein said transmit signal sub-channels are connected in pairs to respective ones of said plurality of signal summers.