A miniaturized, low power RF transmitter with a dual mode active on-chip antenna/inductor is disclosed in which antenna also serves as the oscillator inductor. Also disclosed is a miniaturized low power RF receiver with an on-chip antenna; and a RF transmitter system wherein an on-chip antenna is wirelessly coupled to an off chip patch antenna are disclosed. Advantageously, the TX chip is housed in a low loss, e.g. Low Temperature Co-fired Ceramic (LTCC) package with a patch antenna to provide a System-on-Package implementation comprising electromagnetic coupling between a RF TX chip comprising an integrated on-chip antenna and a package antenna. The on-chip antenna feeds the LTCC patch antenna through aperture coupling, thus negating the need for RF buffer amplifiers, matching elements, baluns, bond wires and package transmission lines, and significantly increases the gain and range of the module with respect to the on-chip antenna alone, without deterioration of the circuit performance and power consumption. Exemplary embodiments are disclosed which may be fabricated using standard CMOS technology, for operation in the 5 GHz U-NII band for applications such as miniaturized, low cost, low power wireless devices and sensor systems.