A fully connected ring oscillator circuit includes a plurality of first ring oscillator loops, a plurality of second ring oscillator loops, a plurality of ring oscillators and a plurality of coupled ring oscillators. Each first ring oscillator loop extends along a first axis. Each second ring oscillator loop extends along a second axis that is transverse to the first axis and intersects each of the first ring oscillator loops. Each ring oscillator includes one of the first ring oscillator loops connected to one of the second ring oscillator loops. Each coupled ring oscillator includes two of the ring oscillators that are connected to each other through a programmable weighted coupling block.