Method and apparatus for feeding over-modulated message signals to antennas of an antenna array
AssigneeAlcatel
InventorGiuseppe Bertocchi
Life of this patent
Estimating the term…
Abstract
A feeding method and device, particularly for a Doppler VOR system, and to a Doppler VOR system using such a feeding device. The feeding method performs a blending function, which is an approximation of the sinX/X function limitedly to the three central lobes, and is obtained by amplitude overmodulation of a single signal according to a periodic function. The blending function can be controlled through the control of the periodic function.
Claims10
A method of feeding a message signal to antennas of an antenna array, in particular of a Doppler VOR system, comprising the steps of:
- performing a blending function that gradually switches said message signal between said antennas by using a modulated message signal generated by modulating the amplitude of said message signal with a periodic signal having a modulation index greater than 100%;
- and
- providing each antenna with a corresponding time fraction of said modulated message signal.
A feeding device for a system provided with an antenna array, in particular a Doppler VOR system, comprising:
- switching means for switching a modulated message signal between the antennas of said antenna array;
- filter means for performing a blending function in order that said switching of a message signal between the antennas of the antenna array is gradual and wherein the filter means comprises at least one amplitude modulator capable of modulating said message signal with a periodic signal having a modulation index greater than 100% (percent) to generate the modulated message signal;
- and
- a control logic unit for controlling said switching means and said filter means.
A Doppler VOR system having an antenna array, comprising:
- switching means for switching a modulated message signal between antennas of said antenna array;
- filter means for performing a blending function in order that said switching of the modulated message signal between the antennas of the antenna array is gradual and wherein the filter means comprises at least one amplitude modulator capable of modulating a message signal with a periodic signal having a modulation index greater than 100% (percent) to generate the modulated message signal;
- and
- a control logic unit for controlling said switching means and said filter means by providing to each antenna a corresponding time fraction of the modulated message signal.
Dependencies are inferred from the claim text.