The National Weather Service (NWS), Federal Aviation Administration (FAA), and Department of Defense (DoD) maintain several networks of independent ground-based radars (NEXRAD, TDWR, ASR, ARSR) for weather surveillance and air traffic surveillance and control. The NWS is in the process of deploying the dual polarization (dual-pol) upgrade on its NEXRAD network. Nonetheless, even with the upgrades, the newest of radar systems in these networks are based mainly on technology a decade or more old. As the legacy systems age, agencies are considering a consolidated network of Multi Function Phased Array Radar (MPAR). To carry out the weather mission, MPAR would be required to provide the dual-pol comparable to that in the legacy NEXRAD parabolic dishes. The operational parabolic dish with dual-pol capability has extremely good cross polarization isolation (cross-pol). It is understood that any radar to replace the current NEXRAD system must demonstrate similar cross-pol characteristics. Our research and development (R&D) efforts are in addressing potential risks from replacing legacy dish radar with a modern phased array radar. One focus area is in achieving the high dual-pol quality. Theoretical and measured data support the use of orthogonal waveforms to significantly improve cross-pol performance. An S-band phased array panel consisting of 144 dual-pol elements was used for the evaluation. A set of waveforms with different Instantaneous Bandwidth and Pulse width product were used to provide cross correlation and sidelobes performance. The results indicate the orthogonal waveforms further improve cross-pol.