Controller-based radio frequency amplifier module and method

• US 6,078,222 A
• Filed: 07/03/1997
• Issued: 06/20/2000
• Est. Priority Date: 07/05/1996
• Status: Expired due to Term

• Current Assignee: Thales Broadcast & Multimedia Incorporated (Groupe Sipromad SA)
• Original Assignee: Thomcast Communications Incorporated (Groupe Sipromad SA)
• Inventors: Harris, Clifford, Correa, Paulo, Ungvarsky, Carl
• Primary Examiner(s): Mottola, Steven J.
• Application Number:
  US08/887,940
• Time in Patent Office: 1,083 Days
• Field of Search: 330/277, 330/285, 330/286, 330/295, 330/298
• US Class Current: 330/295
• CPC Class Codes: H01P 1/2138 using hollow waveguide filters H01P1/2131 takes precedence
• CPC Class Codes: H01Q 3/267 Phased-array testing or checking devices
• CPC Class Codes: H03F 1/526 protecting by using redundant amplifiers
• CPC Class Codes: H03F 2200/294 the amplifier being a low noise amplifier [LNA]
• CPC Class Codes: H03F 2200/372 Noise reduction and elimination in amplifier
• CPC Class Codes: H03F 3/602 Combinations of several amplifiers
• CPC Class Codes: H03G 1/0088 using discontinuously variable devices, e.g. switch-operated
• CPC Class Codes: H03G 3/3042 in modulators, frequency-changers, transmitters or power amplifiers transmission power control in bidirectional transmission systems H04W52/04
• CPC Class Codes: H04L 1/22 using redundant apparatus to increase reliability
• CPC Class Codes: H04W 52/52 using AGC [Automatic Gain Control] circuits or amplifiers

Abstract

A controller-based radio frequency amplifier method and module are employed in a modular transmission system in which respective of the controller-based radio frequency amplifier modules amplify a portion of a signal that is input into the system. Each amplifier module includes an amplifier submodule have a plurality of discrete amplifiers arranged in an amplifier chain, a processor submodule is configured to control a level of the amplified output signal that is output from each amplifier module, a power supply module, and an enclosure. The processor submodule is configured to control the discrete amplifiers in the amplifier submodule such that the module may be removed or added to the system without damaging the power amplifier module or other system components.

Claims

1. A power amplifier module for amplifying an input signal applied thereto and providing an amplified output signal to a N-way radial combiner that combines said amplified output signal with other amplified output signals from other power amplifier modules, said power amplifier module comprising:

an amplifier submodule comprising a plurality of discrete amplifiers arranged in an amplifier chain which amplifies said input signal and provides an amplified output signal, each discrete amplifier having a gate terminal, a drain terminal and a source terminal, each amplifier having a gate-to-source voltage applied between said gate terminal and said source terminal and a drain voltage applied to said drain terminal;

a processor submodule configured to control a level of said amplified output signal, comprising,

a monitoring mechanism configured to monitor respective gate-to-source voltages and said drain voltages,

a comparison mechanism configured to compare said gate-to-source voltages and said drain voltages as monitored by said monitoring mechanism with predetermined gate-to-source voltages and drain voltages, and

an adjustment mechanism configured to adjust at least one of said respective gate-to-source voltages and said drain voltages;

a power supply submodule configured to supply said drain voltages to said discrete amplifiers in said amplifier submodule, said processor submodule configured to apply said gate-to-source voltages to said discrete amplifiers in said amplifier submodule;

a bus connected to said power supply submodule, said processor submodule and said amplifier submodule for transferring data, voltages, and control commands therebetween; and

an enclosure having an internal portion that houses at least said amplifier submodule, said processor submodule, and said bus therein.

2. The power amplifier module of claim 1, wherein said processor submodule comprises a processing unit programmed to respond to at least one of a command sent from a system controller and an internally detected fault condition, said processing unit controlling said respective gate-to-source voltages and said drain voltages via said power supply submodule when said processor submodule enters a cold standby mode of operation, a transition mode of operation, a hot-standby mode of operation, a transmit mode of operation and a failed mode of operation.

3. The power amplifier module of claim 2, wherein:

said input signal is in the wireless cable frequency range; and

said processor turns off said discrete amplifiers in said amplifier chain when in the cold standby mode of operation.

4. The power amplifier module of claim 2, wherein, when in said transition mode of operation, said processor is configured to successively control respective gate-to-source voltages so as to pinch-off respective channels in said discrete amplifiers, increase respective drain voltages, and then adjust said respective gate-to-source voltages to normal operating voltages.

5. The power amplifier module of claim 2, wherein, when in said hot-standby mode of operation, said processor is configured to adjust said respective drain voltages and gate-to-source voltages to remain at normal operating voltages although said input signal is disconnected from said amplifier chain so that said amplifier chain does not amplify said input signal.

6. The power amplifier module of claim 2, wherein, when in said transmit mode of operation, said processor is configured to adjust respective drain voltages and gate-to-source voltages of said discrete amplifiers to normal operating voltages and connect said input signal to said amplifier chain so that said amplifier chain amplifies said input signal.

7. The power amplifier module of claim 2, wherein, when in said failed mode of operation, said processor is configured to turn off respective discrete amplifiers and send a message to a system controller indicating that said power amplifier module has failed.

8. The power amplifier module of claim 1, further comprising:

a coupler configured to monitor an output power of said amplified output signal and produce a monitored output power parameter that is communicated to said processor submodule; and

a signal level adjustment mechanism connected to said amplifier chain and configured to adjust a level of said input signal applied to said amplifier chain, wherein

said processor submodule being configured to control a level at which said amplified output signal is output by comparing said monitored output power parameter with a predetermined range of values, and if said monitored output power parameter is outside of said predetermined range, controlling said signal level adjustment mechanism to bring said amplified output signal to within said predetermined range.

9. The power amplifier module of claim 8, wherein:

said monitored output power parameter comprises a forward power parameter and a reflected power parameter, said processor submodule being configured to turn-off said amplifier module and send a message to a system controller indicating said power amplifier has failed if said reflected power parameter exceeds a predetermined threshold.

10. The power amplifier module of claim 1, further comprising a local bus connector configured to connect to another bus through which data is communicated between said processor submodule and said other power amplifier modules.

11. The power amplifier module of claim 1, wherein said enclosure comprises a conductive material, said internal portion being defined by opposing walls, at least one of said opposing walls having a channel formed therein having a depth and width of sufficient size to hold said bus therein, said metallic material and said channel cooperating to reduce electromagnetic interference generated by said amplifier submodule, said processor submodule and said power supply submodule.

12. The power amplifier module of claim 11, wherein said internal portion of said enclosure comprises electromagnetic isolation shields that subdivide said internal portion into compartments that host said amplifier submodule, said processor submodule and said power supply submodule, said channel extending between at least two of said compartments.

13. The power amplifier module of claim 1, further comprising:

a chassis; and

a backplane having a plurality of connectors formed thereon, wherein said enclosure is configured to slide within said chassis and plug into at least one of said plurality of connectors.

14. The power amplifier module of claim 2, wherein said enclosure assembly comprises a front-panel having an interlock switch disposed thereon, said processor submodule configured to detect when said interlock switch is actuated by a user and respond by entering said cold standby mode of operation by sequentially changing respective of said gate-to-source voltages of said discrete amplifiers to pinch-off respective channels of said discrete amplifiers, and substantially reducing said drain voltage prior to enabling said power amplifier to be disconnected from said N-way radial combiner.

15. The power amplifier module of claim 1, wherein said processor submodule comprises a module shut-down mechanism configured to turn off said discrete amplifiers in response to receiving a shut-down message received from a system controller, said processor submodule causing said discrete amplifiers to shut-off by sequentially changing respective of said gate-to-source voltages of said discrete amplifiers so as to pinch-off respective channels of said discrete amplifiers, and substantially reducing said drain voltage prior to enabling said power amplifier to be disconnected from said N-way radial combiner.

16. A power amplifier module for amplifying an input signal applied thereto and providing an amplified output signal to a radial combiner that combines said amplified output signal with other amplified output signals from other power amplifier modules, said power amplifier module comprising:

means for amplifying said input signal and providing an amplified output signal, comprising,

a plurality of discrete amplifiers, and

means for applying a gate-to-source voltage and a drain voltage to respective of said discrete amplifiers;

means for controlling a level of said amplified output signal, comprising,

means for monitoring said gate-to-source voltage and said drain voltage of respective of said discrete amplifiers,

means for comparing said gate-to-source voltage and said drain voltage of respective of said discrete amplifiers with predetermined gate-to-source voltages and drain voltages, and for producing a comparison result, and

means for adjusting at least one of said gate-to-source voltage and said drain voltage of respective of said discrete amplifiers based on said comparison result;

means for transferring data, voltages, and control commands between said means for amplifying and means for controlling; and

means for enclosing said means for amplifying, means for controlling, and means for transferring in a single enclosure.

17. The power amplifier module of claim 16, further comprising means for responding to at least one of a command sent from a system controller and an internally detected fault condition by operating said means for controlling in one of a cold standby mode of operation, a transition mode of operation, a hot-standby mode of operation, a transmit mode of operation and a failed mode of operation.

18. The power amplifier module of claim 16, further comprising:

means for monitoring an output power of said amplified output signal and producing a monitored output power parameter; and

means for adjusting a level of said input signal applied to said amplifier chain by comparing said monitored output power parameter with a predetermined range of values and if said monitored output power parameter is outside of said predetermined range, bringing said amplified output signal to within said predetermined range.

19. The power amplifier module of claim 16, wherein said means for enclosing further comprises means for reducing electromagnetic interference between said means for amplifying, means for controlling and means transferring.

20. The power amplifier module of claim 16, further comprising means for mounting said power amplifier module in a rack by pluggably connecting said power amplifier module to a backplane configured to host said other power amplifier modules.

21. The power amplifier module of claim 16, further comprising means for disconnecting said power amplifier module from said radial combiner while said other power amplifier modules continue to amplify said input signal.

22. The power amplifier module of claim 21, further comprising:

means for receiving a shut-down message from at least one of a system controller and a fault detection mechanism; and

means for responding to said shut-down message by sequentially changing respective of said gate-to-source voltages of said discrete amplifiers so as to pinch-off respective channels of said discrete amplifiers, and substantially reducing said drain voltage of said discrete amplifiers.

23. A method for amplifying an input signal applied a power amplifier and providing an amplified output signal to a radial combiner that combines said amplified output signal with other amplified output signals from other power amplifier modules, said method comprising the steps of:

amplifying said input signal by applying said input signal to a plurality of discrete amplifiers;

applying a gate-to-source voltage and a drain voltage to respective of said discrete amplifiers;

controlling with a processor a level of said amplified output signal, comprising the steps of,

monitoring said gate-to-source voltage and said drain voltage of respective of said discrete amplifiers,

comparing said gate-to-source voltage and said drain voltage of respective of said discrete amplifiers with predetermined gate-to-source voltages and drain voltages, and producing a comparison result, and

adjusting at least one of said gate-to-source voltage and said drain voltage of respective of said discrete amplifiers based on said comparison result; and

enclosing said discrete amplifiers and said processor in a single enclosure.

24. The method of claim 23, further comprising the step of responding to at least one of a command sent from a system controller and an internally detected fault condition by operating said discrete amplifiers in one of a cold standby mode of operation, a transition mode of operation, a hot-standby mode of operation, a transmit mode of operation and a failed mode of operation.

25. The method of claim 23, further comprising the steps of:

monitoring an output power of said amplified output signal and producing a monitored output power parameter; and

adjusting a level of said input signal applied to said discrete amplifiers by comparing said monitored output power parameter with a predetermined range of values and if said monitored output power parameter is outside of said predetermined range, bringing said amplified output signal to within said predetermined range.

26. The method of claim 23, further comprising the step of mounting said single enclosure in a rack with similar enclosures that enclose said other power amplifiers.

27. The method of claim 23, further comprising the step of disconnecting said power amplifier from said radial combiner while said other power amplifiers continue to amplify said input signal.

28. The method of claim 23, further comprising the steps of:

receiving a shut-down message from at least one of a system controller and a fault detection mechanism; and

responding to said shut-down message by sequentially changing respective of said gate-to-source voltages of said discrete amplifiers so as to pinch-off respective channels of said discrete amplifiers, and substantially reducing said drain voltage of said discrete amplifiers.