TCAS transmitter phase tuning system and method
AssigneeRockwell Collins, Inc.
InventorsSami R. Wahab, Constantinos S. Kyriakos, Charles L. Holecek
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Abstract
A TCAS receiver/transmitter which uses an improved calibration scheme for improving the ability of the device to transmit in a narrow directional field where the device uses the transmitter frequency source to generate signals for calibration purposes. The calibration uses a technique of simultaneously transmitting from two antennas and manipulating the phase of the signal through successive settings. The signals are monitored by the remaining two antennas and calibration adjustments are made in response thereto.
Claims20
A transmitter on board an aircraft for making directionally targeted transmissions to other aircraft, comprising:
- at least four antenna elements coupled to at least one transmission source operating at a predetermined interrogation frequency;
- and
- a transmitter calibration signal source operating at said predetermined interrogation frequency for providing calibration signals used in controlling phase relationship between interrogation signals radiating from said at least four antennas.
A method of calibrating a transmitter having at least four antenna elements in an array;
- the method comprising the steps of:
- providing an array of four antenna elements;
- providing a first test signal simultaneously across two adjacent antenna elements of said array;
- rotating a phase characteristic of one of said two adjacent antenna elements, through at least two phase settings;
- and measuring a phase characteristic of a signal received at each of a remaining two antenna elements of said array.
A directional transmitter/antenna assembly comprising:
- an array of four or more antenna elements disposed around a periphery of a predetermined area for receiving responses from intruding aircraft and for radiating interrogations at a first predetermined frequency;
- a plurality of receivers for processing signals received by said antenna elements;
- and
- a transmission calibration source operating at said first predetermined frequency used for generating a calibration signal which is radiated by one of said four or more antenna elements and thereafter received by a first and second other of said four or more antenna elements.
A TCAS transmitter comprising:
- first means for radiating electromagnetic energy at a predetermined frequency and with a first predetermined phase characteristic;
- second means for radiating electromagnetic energy at a predetermined frequency and with a second predetermined phase characteristic;
- third means for radiating electromagnetic energy at a predetermined frequency and with a third predetermined phase characteristic;
- fourth means for radiating electromagnetic energy at a predetermined frequency and with a fourth predetermined phase characteristic;
- means for simultaneous radiating electromagnetic energy from said first means radiating and said fourth means for radiating;
- means for rotating said fourth predetermined phase characteristic through at least two phase settings and measuring a phase characteristic of a signal received by said second and third means for radiating.
Dependencies are inferred from the claim text.