Single-Layered Push-Pull and Push-Push Oscillator with Asynchronous Sum and Difference Network

This paper presents a push-pull and push-push oscillator utilizing single-layered asynchronous sum and difference network. The sub-oscillators are realized in a series-feedback configuration by employing a two-port SIW cavity at the TE 101 mode. The sub-oscillators exhibit out-of-phase performance at the fundamental frequency $f_{0}$ and in-phase performance at the second-harmonic frequency $2f_{0}$ , respectively. A four-port SIW network with asynchronous sum and difference response is built by exploiting the $\mathbf{TE}_{201}$ and TE 104 modes, corresponding to the $f_{0}$ and $2f_{0}$ , individually. By combining the two-port SIW-based sub-oscillators and the four-port SIW network together in a single-layered structure, the prototype exhibits the function of the push-pull and push-push oscillator, simultaneously.