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 for digital beamforming comprising:
(a) receiving, by a digital beamformer from a first principal polarization frequency converter, a first modulated signal associated with a first intermediate frequency;
(b) converting, by the digital beamformer, the first modulated signal to a digital data format to provide first digital data;
(c) generating, by the digital beamformer, a first plurality of channels of digital data by decimating the first digital data using a first polyphase channelizer and filtering using a first plurality of cascaded halfband filters;
(d) selecting, by the digital beamformer, a first channel of the first plurality of channels;
(e) applying, by the digital beamformer, a first weighting factor to the first digital data associated with the first channel to generate a first intermediate partial beamformed data stream;
(f) combining, by the digital beamformer, the first intermediate partial beamformed data stream with a plurality of other intermediate partial beamformed data streams to generate a first partial beamformed data stream;
(g) applying, by the digital beamformer, a first oscillating signal to the first partial beamformed data stream to generate a first oscillating partial beamformed data stream;
(h) applying, by the digital beamformer, a first three-stage halfband filter to the first oscillating partial beamformed data stream to generate a first filtered partial beamformed data stream;
(i) applying, by the digital beamformer, a first time delay to the first filtered partial beamformed data stream to generate a first partial beam, wherein the first partial beam is of a first beam; and
(j) transmitting, from the digital beamformer, via a data transport bus to a digital software system interface, the first partial beam of the first beam, which is transmitted via the data transport bus along with a first set of a plurality of other partial beams of the first beam.
2. The method of claim 1 , wherein the first intermediate frequency is between 50 MHz and 1250 MHz.
3. The method of claim 1 , wherein the step of converting the first modulated signal from the analog signal to the digital data format is performed using First-Nyquist sampling.
4. The method of claim 1 , wherein the step of selecting a first channel of the first plurality of channels is performed using a first multiplexer.
5. The method of claim 1 , wherein the first partial beam of the first beam is also transmitted via the data transport bus along with a second set of a plurality of other partial beams of a second beam.
6. The method of claim 1 , wherein the method further comprises:
(k) receiving, by a second digital beamformer, from a first orthogonal polarization frequency converter, a second modulated signal associated with the first intermediate frequency;
(l) converting, by the second digital beamformer, the second modulated signal to a digital data format to provide second digital data;
(m) generating, by the second digital beamformer, a second plurality of channels of digital data by decimating the second digital data using a second polyphase channelizer and filtering using a second plurality of cascaded halfband filters;
(n) selecting, by the second digital beamformer, a second channel of the second plurality of channels;
(o) applying, by the second digital beamformer, a second weighting factor to the second digital data associated with the second channel to generate a second intermediate partial beamformed data stream;
(p) combining, by the second digital beamformer, the second intermediate partial beamformed data stream with a second plurality of other intermediate partial beamformed data streams to generate a second partial beamformed data stream;
(q) applying, by the second digital beamformer, a second oscillating signal to the second partial beamformed data stream to generate a second oscillating partial beamformed data stream;
(r) applying, by the second digital beamformer, a second three-stage halfband filter to the second oscillating partial beamformed data stream to generate a second filtered partial beamformed data stream;
(s) applying, by the second digital beamformer, a second time delay to the second filtered partial beamformed data stream to generate a second partial beam, wherein the second partial beam is of the first beam; and
(t) transmitting, by the second digital beamformer, via the data transport bus to the digital software system interface, the second partial beam of the first beam, which is transmitted via the data transport bus along with a second set of a plurality of other partial beams of the first beam.
7. The method of claim 6 , wherein the step of converting the second modulated signal from the analog signal to the digital data format is performed using First-Nyquist sampling.
8. The method of claim 6 , wherein the step of selecting the second channel of the second plurality of channels is performed using a second multiplexer.
9. The method of claim 6 , wherein the second oscillating signal is the same as the first oscillating signal.
10. The method of claim 6 , wherein the second channel is the same as the first channel.
11. The method of claim 6 , wherein the second partial beam of the first beam is also transmitted via the data transport bus along with a third set of a plurality of other partial beams of a second beam.