Phase noise in a four-element array of oscillating antennas is analyzed for
a loop configuration and a unilateral coupling topology. It is demonstrate
d that this structure, basically designed for circular polarization (CP) ap
plications, also yields a 75% reduction of the near-carrier phase noise com
pared to a single oscillator. Experimental validation is made at 4 GHz. For
this structure, deviation of the coupling phase from its nominal value has
no influence on the phase noise performance.