Patent ID: 8797105

Claim:
A tunable signal source comprising: a plurality of oscillator cores each having a coupling input, a coupling output, and a power output that is common to each of the plurality of oscillator cores; a plurality of tunable phase shifters wherein corresponding ones of the plurality of tunable phase shifters are communicatively coupled between the coupling input and the coupling output of corresponding ones of the plurality of oscillator cores, thereby forming a loop of alternating ones of the plurality of oscillator cores and alternating ones of the plurality of tunable phase shifters; and a plurality of couplers wherein corresponding ones of the plurality of couplers are coupled between corresponding ones of the plurality of tunable phase shifters and corresponding ones of the plurality of oscillator cores to buffer the plurality of oscillator cores from the plurality of tunable phase shifters, wherein coupling modes are controllable via injection of current between the plurality of oscillator cores.