System and method of generating a radio frequency signal
AssigneeIndra Australia Pty Limited
InventorsDavid Le Comte, Andrew Cain
Life of this patent
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Abstract
A system and method of generating a radio frequency signal adapted for allowing a receiving device to calculate a navigational indicator relative to a plurality of antennas. The system comprising a radio frequency generator unit for generating: a primary signal for driving at least one antenna of the plurality of antennas to provide a primary transmission; and an actively derived secondary signal to complement the primary signal for driving at least one other antenna of the plurality of antennas to provide, collectively with the primary transmission, the combined transmission, wherein the combined transmission, relative to the primary transmission only, provides a reduced observed distortion at the receiving device.
Claims27
A system for providing a combined transmission for allowing a receiving device to calculate a navigational indicator relative to a plurality of antennas, the system comprising a radio frequency generator unit for generating:
- a primary signal for driving at least one antenna of the plurality of antennas to provide a primary transmission;
- and
- an actively derived secondary signal to complement the primary signal for driving at least one other antenna of the plurality of antennas to provide, collectively with the primary transmission, the combined transmission,
- wherein the combined transmission, relative to the primary transmission only, provides a reduced observed distortion at the receiving device.
A system according to any one of the preceding claims, wherein the plurality of antennas are arranged circumferentially about a circle, wherein the frequency generator unit is adapted to generate:
- a first set of signals including at least two primary and two secondary signals for driving four adjacent antennas of the plurality of antennas;
- a second set of signals including at least two primary and two secondary signals for driving four adjacent antennas of the plurality of antennas;
- wherein the first and second sets of signals are coupleable to diametrically located antennas to simultaneously drive two sets of at least four adjacent antennas such that each set of antennas are substantially diametrically located on the circle.
A system according to any one of the preceding claims, wherein the system comprises a means for dynamically selectively coupling each primary and secondary signal to an antenna of the plurality of antennas, such that the source of the combined transmission is transitionable in a substantially continuous cycle about the circumference of the circle.
A system according to anyone of the preceding claims, wherein the distortion arises from the juxtaposition of the plurality of antennas.
A system, according to anyone of the preceding claims wherein the distortion arises from simultaneous transition from two or more antennas of the plurality of antennas.
A system according to anyone of the preceding claims wherein the distortion includes AM modulation of the combined transmission observed at the receiving device.
A system according to anyone of the preceding claims, wherein the frequency generator unit is further adapted to generate a respective reference signal for driving an antenna to provide a reference transmission.
A system according to anyone of the preceding claims, wherein the frequency generator unit is adapted to dynamically control phase, frequency and amplitude of each of the primary and secondary signals.
A system according to anyone of the preceding claims, wherein the frequency generator unit includes a plurality of numerically controlled oscillators for actively independently generating each of the primary and secondary signals.
A system according to anyone of the preceding claims, wherein the navigational indicator is a directional indicator relative to the plurality of antennas.
A system for generating a doppler very high frequency omni-directional range (D-VOR) air navigation signal comprising:
- a radio frequency generator unit for actively generating a plurality of signals,
- an antenna distribution system (ADS) coupled to the frequency generator unit;
- a plurality of circumferentially located omni-directional sideband antennas;
- a centrally located reference antenna;
- wherein the antenna distribution system is adapted to selectively drives diametrically located predetermined sets of the sideband antennas.
Dependencies are inferred from the claim text.