Design of a millimeter-wave CMOS radiation oscillator with an above-chip patch antenna

This brief presents a design method of a millimeter-wave CMOS radiation oscillator for broadband short-range communication. An above-chip patch antenna is proposed for the radiation oscillator. The proposed antenna has a balanced port, which makes it suitable for the direct connection of CMOS cross-coupling transistors. The properties of the antenna are analyzed by an electromagnetic field solver, and, in particular, the input resistance is discussed in detail, so that the condition of millimeter-wave oscillation is satisfied even by CMOS FETs having gains lower than GaAs FETs. Furthermore, on/off-keying modulation can be carried out using switch transistors, and two switching techniques are used to realize a large data rate. A performance of 500 Mb/s and a total efficiency of 0.12, which includes both the antenna and the circuit efficiencies, are confirmed by circuit simulation.