A study of wide-band time-delayed phased-arrays with phase and frequency encoded signals for arrival-time measurement
Phase-encoded signals are useful for arrival-time estimation after correlation. The bandwidth to carrier frequency ratio for the phase-encoded signals used in certain applications is very high. As the narrow-band assumption is violated, conventional phase-tuned phased-arrays suffer from dispersio...
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| Language: | English |
| Published: |
2009
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| Online Access: | http://hdl.handle.net/2429/7772 |
| Summary: | Phase-encoded signals are useful for arrival-time estimation after correlation. The bandwidth
to carrier frequency ratio for the phase-encoded signals used in certain applications is very
high. As the narrow-band assumption is violated, conventional phase-tuned phased-arrays
suffer from dispersion and do not function properly for these applications. Time-delayed
phased-arrays do not suffer from dispersion and function normally under the wide-band
requirement. This thesis studies the time-delayed array and three types of modulated signals:
linear Frequency Modulated (FM) signal, complementary Barker-coded Phase Modulated
(PM) signal and Golomb-coded P M signal, for the purpose of arrival-time estimation. It is
shown that the time-delay tuning for the linear F M signal is equivalent to linearly offsetting
the initial frequency and adding a quadratic phase across the array. A new way of adjusting
the element spacing for the time-delayed phased-array for the three types of signal to
minimize off-tuning angle correlation is presented. Performance of the time-delayed phasedarray
using the three types of signal are simulated and compared. Experiments have been
performed to verify the practicality of the time-delayed phased-array. |
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