An oscillation module includes: an oscillation circuit which includes a first coil and a second coil; and a filter circuit which is provided at a stage subsequent to the oscillation circuit and includes a third coil, in which the first coil, the second coil, and third coil are a part of an integrated circuit, and the third coil is arranged so as to intersect a virtual straight line equidistant from the center of the first coil and the center of the second coil, in a plan view of the integrated circuit.

An oscillation module includes: an oscillation circuit; a multiplication circuit which is provided at a stage subsequent to the oscillation circuit and is operated by differential motion; and an output circuit which is provided at a stage subsequent to the multiplication circuit.

In some aspects, a wireless sensor device includes a voltage controlled oscillator. The voltage controlled oscillator includes a first inverter, a second inverter, and a transformer connected between the first and second inverters. The first inverter includes a first inverter input node and a first inverter output node. The second inverter includes a second inverter input node and a second inverter output node. The transformer includes a primary winding portion, a first secondary winding portion, and a second secondary winding portion. The primary winding portion is connected between the first inverter output node and the second inverter output node and is inductively coupled to the first and second secondary winding portions. The first secondary winding portion is connected between the primary winding portion and the first inverter input node. The second secondary winding portion is connected between the primary winding portion and the second inverter input node.

In accordance with an embodiment, a voltage controlled oscillator (VCO) includes a VCO core having a plurality of transistors and a varactor circuit that has a first end coupled to emitter terminals of the VCO core and a second end coupled to a tuning terminal. The varactor circuit includes a capacitance that increases with increasing voltage applied to the tuning terminal with respect to the emitter terminals of the VCO core.

A dual tank LC-tuned Voltage Controller Oscillator (LC VCO) comprising a differential pair of cross-coupled transistors (M.sub.1, M.sub.2, M.sub.3, M.sub.4) produces a negative impedance by keeping a lower drain swing and a sufficient gate swing. The gate terminals of first and second transistors M.sub.1, M.sub.2 and third and fourth transistors M.sub.3, M.sub.4 are separated through a series of two inductors L.sub.1, L.sub.2 and two cross-coupled capacitors are connected between the drain and gate terminals of cross-coupled transistors to attenuate the output swing. The VCO tank further comprises two R2R Digital to Analog Converters (DAC) to bias both NMOS and PMOS cross-coupled pairs of transistors, to produce a common mode noise.