System and method for a digitally beamformed phased array feed
Systems and methods are provided for a digital beamformed phased array feed. The system may include a radome configured to allow electromagnetic waves to propagate; a multi-band software defined antenna array tile; a power and clock management subsystem configured to manage power and time of operation; a thermal management subsystem configured to dissipate heat generated by the multi-band software defined antenna array tile; and an enclosure assembly. The multi-band software defined antenna array tile may include a plurality of coupled dipole array antenna elements; a plurality of frequency converters; and a plurality of digital beamformers.
1 . A method of transmitting radio signals from a moving vehicle, the method comprising:
a. receiving, at a first beamformer, a first partial beam of a first beam of a plurality of beams via a data transport bus;
b. receiving, at a second beamformer, a second partial beam of the first beam of the plurality of beams via the data transport bus;
c. applying, by the first beamformer, a first weighting factor to the first partial beam to form first transmit digital data associated with the first partial beam;
d. applying, by the first beamformer, a second weighting factor to the second partial beam to form second transmit digital data associated with the second partial beam;
e. converting, by a first digital to analog converter operatively connected to the first beamformer, the first transmit digital data to a first analog signal having a first intermediate frequency;
f. converting, by a second digital to analog converter operatively connected to the second beamformer, the second transmit digital data to a second analog signal having the first intermediate frequency;
g. converting, by a first principal polarization frequency converter of a first pair of frequency converters of a plurality of pairs of frequency converters operably connected to the first digital to analog converter and the second digital to analog converter, a first modulated signal associated with the first analog signal into a second modulated signal associated with a first radio frequency;
h. converting, by a first orthogonal polarization frequency converter of the first pair of frequency converters, a third modulated signal associated with the second analog signal into a fourth modulated signal associated with the first radio frequency;
i. transmitting, from the first principal polarization frequency converter to a first principal polarization component oriented in a first direction of a respective coupled dipole array antenna element of a plurality of coupled dipole array antenna elements, the second modulated signal;
j. transmitting, from the first orthogonal polarization frequency converter to a first orthogonal polarization component oriented in a second direction of the respective coupled dipole array antenna element of the plurality of coupled dipole array antenna elements, the fourth modulated signal;
k. transmitting, by the first principal polarization component of the respective coupled dipole array antenna element away from the moving vehicle, the second modulated signal; and
l. transmitting, by the first orthogonal polarization component of the respective coupled dipole array antenna element away from the moving vehicle, the fourth modulated signal.
2 . The method of claim 1 , wherein the plurality of coupled dipole array antenna elements are tightly coupled relative to a wavelength of operation.
3 . The method of claim 1 , wherein the plurality of coupled dipole array antenna elements are spaced at less than half a wavelength of operation.
4 . The method of claim 1 , wherein the first intermediate frequency is between 50 MHz and 1250 MHz.
5 . The method of claim 1 , wherein the first radio frequency is between 900 MHz and 6000 MHz.
6 . The method of claim 1 , wherein the first radio frequency is between 2000 MHz and 12000 MHz.
7 . The method of claim 1 , wherein the first radio frequency is between 10000 MHZ and 50000 MHz.