Narrowband DOA Beamforming techniques on Wideband signal
My suspicion is that you can only perform phase shift beamforming techniques on narrowband signals and will not work even if you are looking for a narrowband within a wideband signal. Am I correct?


No; the correlation coefficient of your reference signal to your received signal should, given additive, phase-uniform, white noise, have an expectation value of the phase shift the individual receiver sees, no matter how wide your band is.

Note that this is only true if your transmitter/receiver system can be modeled as linear phase for the bandwidth we're talking about, but without loss of generality, radar/sonar/sound systems are designed to pretty much have exactly that characterestic.