We present a conceptual framework of planar SIS mixer array receivers and the studies on the required techniques. This concept features membrane-based on-chip waveguide probes and a quasi-two-dimensional local-oscillator distribution waveguide network. This concept allows sophisticated functions, such as dual-polarization, balanced mixing and sideband separation, easily implemented with the SIS mixer array in the same planar circuit. We have developed a single-pixel prototype receiver by implementing the concept in the design. Initial measurement results show good evidences that support the feasibility of the concept.