A passive pattern- and polarization-reconfigurable block cell antenna (BCA) concept is presented in 28 GHz. Conceptually, the operating principle of the BCA is similar to that of a field-programmable gate array (FGPA) chip. Various antenna characteristics can be achieved by adjusting the weighting matrix of the BCA ports. The proposed BCA topology is fully compatible with currently existing millimeter-wave (mmWave) 5G phased-array architectures. In addition, the unit BCA can be modularly expanded into a 2-D, symmetric topology to exhibit a wide range of directivities, polarization, and main beam direction. This concept is exemplified using a 28 GHz beamforming reference module featuring a 2 bit phase and 1 bit magnitude resolution. The 15 distinct modes selected from theoretically available modes are experimentally demonstrated. [ABSTRACT FROM AUTHOR]