Investigation of Mutual Injection Locking on Resonant-Tunneling-Diode Oscillators

An RTD patch oscillator concept is presented based on electroplated patch antennas, supported by Benzocyclobuten as a dielectric. With the utilized double-barrier RTD layer stack, a single pixel output power of -8.7dBm and a DC-to-RF conversion efficiency of 3.5% are estimated. The design enables the use of mutual injection locking between adjacent oscillator pixels in an arrayed configuration. We investigate the mutual injection locking behaviour based on transient simulations, including 3D EM-simulated S-parameter blocks of the integrated patch antenna. A two- and four-element array is analyzed with respect to locking performance and phase relations. Far-field simulations of arrays with up to 1×4 elements were carried out utilizing superposition of fields. The presented design enables for spatial power combining of more than one RTD oscillator via synchronized pixels.