In this paper, an affordable and miniaturized 140 GHz transmit/receive (TRX) array antennaon-package (AoP) is proposed through the conventional printed circuit board process employing a single substrate. The proposed design approach involved an in-depth analysis of the potential performance degradation of a D-band antenna operating within a coarse process and a practical design guide for the configuration of matching network packaging with robust wedge bonding. An asymmetric matching network design technique for 1×4 array antenna packaging considered the 1-bit digital beamforming capabilities of radio frequency integrated circuits (RFIC). In its unprecedented demonstration, an AoP with 1×2 transmitting and 1×4 receiving antennas was packaged with an RFIC. The measurements arrayed maximum gains of the transmit and receive antennas were 9.8 and 11.8 dBi, respectively. In addition, gain bandwidths of 12.6% and 20.4% were achieved for the transmit and receive antennas, respectively. This study marked the first instance of fabricating a TRX AoP using a single RF metal layer via a width/gap process condition of 100/80 µm in the D-band.INDEX TERMS Antenna-on-package (AoP), affordable, array, printed circuit board (PCB), single-layer, sixth generation (6G), wedge bonding, wide-band.