Wideband Array Antenna Using I-F Time Delay Steering

摘要

If time delay steering of a wideband array antenna is introduced at the i-f frequency instead of at the r-f level, all of the element signal phases will be different and the summed pulses will not add in-phase to produce a beam in the desired direction. It is found that when i-f delay steering is used, an additional incremental phase shift must be introduced into the local oscillator of each mixer to produce in-phase summation. The delay provides alignment of the envelopes while the local oscillator phase shift provides in-phase summation. This condition is found to be independent of frequency and thus bandwidth. The effect of i-f delay error on the system's response is discussed. (Author)