Tile sub-array and related circuits and techniques

A tile subarray contains an upper part multilayer assembly (UMLA) provided from a plurality of 1st printed circuit boards, and a bottom multilayer assembly (LMLA) provided from a plurality of 2nd printed circuit boards. Each of UMLA and LMLA contains one or more radio frequency (RF) interconnection between different circuitry layers on a different circuit board which constitutes UMLA and LMLA. RF interconnection can contain one or more RF consistency pads, and RF consistency pad provides a mechanism for adjusting the impedance characteristic of RF stub, in order to provide RF interconnection which has desired insertion loss and an impedance characteristic over desired RF clock frequency belt. A circuit board which has RF interconnection can be manufactured without needing execution of arbitrary back drills and backfill work with RF consistency pad, in order to remove a stub portion of RF interconnection in UMLA and LMLA.