The development of next generation wireless networks for communication demands low-latency and seamless connectivity. This requires large bandwidth to support the high data rate. Wireless networks operating at higher frequencies provide additional available frequency spectrum. The work presented in this thesis focuses on implementing high performance and efficient circuits to satisfy these needs. First, all-digital massive multi-user multiple-input-multiple-output (mu-MIMO) system is introduced to provide a solution for efficient beamforming to compensate high loss at mm-Wave frequencies. Second, interference-tolerant receivers with high operating frequencies are demonstrated to support next generation wireless communication and sensing applications. Finally, full duplex transceiver which allows transmit and receive simultaneously at the same time and same frequency spectrum is illustrated. Furthermore, the proposed full duplex transceiver enable wireless LO synchronization of randomly located wireless nodes to realize distributed MIMO beamforming in wireless ad hoc networks and enhance connectivity.