Pulse transmitters having multiple outputs in phase relationship and methods of operation

• US 7,345,626 B2
• Filed: 09/15/2004
• Issued: 03/18/2008
• Est. Priority Date: 09/15/2004
• Status: Active Grant

• Current Assignee: L3 Technologies, Inc. (L3Harris Technologies, Inc.)
• Original Assignee: Aviation Communications And Surveillance Systems, LLC
• Inventors: Stayton, Gregory T., Smith, Mark D.
• Primary Examiner(s): Sotomayor; John B
• Application Number:
  US10/942,727
• Publication Number:
  US 20060057977A1
• Time in Patent Office: 1,280 Days
• Field of Search: 342/175, 342 29- 37, 342 42- 51, 375/297, 455/114.2, 455/115.1
• US Class Current: 342/175
• CPC Class Codes: G01S 13/933 of aircraft or spacecraft
• CPC Class Codes: G01S 7/4008 of transmitters

Abstract

A transmitter provides a plurality of output signals. The transmitter includes a processor, a modulator, a first circuit, and a second circuit. The modulator provides a modulated signal responsive to the processor. The modulated signal includes an amplitude modulated radio frequency for transmitting a pulse. The first circuit provides a first output signal, responsive to and with higher power than the modulated signal. The first output signal has a first phase during transmitting of the pulse. The second circuit provides a second output signal, responsive to and with higher power than the modulated signal. The second output signal has a second phase during transmitting of the pulse. The second phase is controlled by the second circuit in accordance with the first phase, the second phase, and indicia of a third phase provided by the processor.

Claims

1. A transmitter that provides a plurality of output signals, the transmitter comprising:

a processor;

a signal generator that provides a generated signal comprising an amplitude modulated radio frequency for transmitting a pulse;

a first circuit that provides a first output signal, responsive to and with higher power than the generated signal, the first output signal having a first phase during transmitting of the pulse; and

a second circuit that provides a second output signal, responsive to and with higher power than the generated signal, the second output signal having a second phase during transmitting of the pulse, the second phase controlled by the second circuit in accordance with the first phase, the second phase, and indicia of a third phase provided by the processor.

2. The transmitter of claim 1 wherein the second circuit operates to reduce a first absolute difference between the second phase and the first phase.

3. The transmitter of claim 2 wherein the second circuit further operates to reduce a second absolute difference between the first absolute difference and the third phase.

4. The transmitter of claim 3 wherein the second circuit comprises a second processor having a memory that includes a compensation value applied by the processor to reduce the second absolute difference.

5. The transmitter of claim 1 wherein:

the first circuit comprises a first sampling circuit that provides indicia of the first phase; and

the second circuit comprises;

(1) an amplifier that provides the second output signal;

(2) a second sampling circuit that provides indicia of the second phase;

(3) a phase detector that provides an error signal in accordance with the indicia of the first phase and the indicia of the second phase;

(4) a phase controller that provides a phase control signal in accordance with the error signal and the indicia of the third phase; and

(5) a phase shifter that couples the generated signal to the amplifier and introduces an adjustment phase shift in the generated signal in accordance with the phase control signal.

6. The transmitter of claim 1 wherein:

the generated signal further comprises a first portion for synchronization of a provided receiver and a second portion for conveying data in accordance with a phase modulation; and

the first portion comprises the pulse.

7. The transmitter of claim 6 wherein:

the first circuit comprises a first sampling circuit that provides indicia of the first phase; and

the second circuit comprises;

(1) an amplifier that provides the second output signal;

(2) a second sampling circuit that provides indicia of the second phase;

(3) a phase detector that provides an error signal in accordance with the indicia of the first phase and the indicia of the second phase;

(4) a phase controller that provides a phase control signal in accordance with the error signal and the indicia of the third phase; and

(5) a phase shifter that couples the generated signal to the amplifier and introduces an adjustment phase shift in the generated signal in accordance with the phase control signal, the adjustment phase shift not subject to change during transmitting.

8. The transmitter of claim 7 wherein the phase shifter comprises a second processor having a memory that includes a compensation value applied by the processor to reduce the second absolute difference.

9. The transmitter of claim 1 wherein:

the first circuit and the second circuit each comprise a respective power amplifier; and

each output signal of the plurality has a power of greater than 200 watts.

10. The transmitter of claim 1 wherein the pulse is part of a Mode S interrogation.

11. A method performed by a transmitter for transmitting in a Mode S format, the method comprising:

providing an output signal for a first period of time according to a portion of the Mode S format;

during a second period of time included in the first period of time, detecting a first phase of the output signal; and

adjusting a circuit of the transmitter that provided the output signal, adjusting in accordance with the detected first phase to subsequently provide the output signal with a second phase different from the first phase.

12. The system of claim 11 wherein adjusting is performed at least in part while transmitting.

13. A method performed by a transmitter for transmitting in a Mode S format, the method comprising:

providing a plurality of output signals for a first period of time according to a portion of the Mode S format;

during a second period of time included in the first period of time, detecting a respective first phase of each output signal of the plurality; and

adjusting a circuit of the transmitter that provided a particular output signal of the plurality, adjusting in accordance with the detected first phase of each of two output signals of the plurality to subsequently provide the particular output signal with a second respective phase different from the first respective phase.

14. The method of claim 13 wherein adjusting is performed at least in part while transmitting.