This paper presents an overview of approaches to in-band full-duplex (IBFD) phased-array antennas designed for high TX-RX isolation in the 5G FT1 and FT2 spectrums. A variety of signal interference cancellation (SIC) techniques are explored including multiaperture, aperture and element-level approaches to panel designs, reference-based digital cancellation, RF/analogue cancellation and novel front ends for element isolation. Scalability considerations for the panels and the digital signal processing on them are also explored. A survey of measured and simulated performance for a variety of panel designs demonstrates TX-RX isolation in excess of 160 dB in one instance and highlights limitations for future research.