Oscillator and radio equipment

An oscillator comprising:

• an oscillation circuit formed on a dielectric substrate;
• and
• circuit an output transmission line for transmitting oscillation output signals of said oscillation circuit, wherein:
• said output transmission line is a transmission line having cut-off characteristics, said output transmission line including a dielectric material disposed between two conductor plates substantially parallel to each other;
• the cut-off frequency of said transmission line is determined so as to cut off the fundamental wave component, or the fundamental wave component and lower order harmonic components of an oscillation signal generated by said oscillation circuit, so that higher harmonic components having higher frequencies than the cut-off component or components are propagated;
• said output transmission line is a dielectric line formed by disposing a dielectric strip between two conductor plates substantially parallel to each other;
• said oscillation circuit is formed by mounting a negative resistance element in the vicinity of a short-circuit position of a line of which at least one end is opened, the line having a length an integral multiple of a half wavelength;
• and
• said line and said output transmission line are coupled.