Analysis and design of a concurrent dual-band self-oscillating mixer

A concurrent dual-band self-oscillating mixer, based on a ring resonator, is proposed and analyzed in detail. Taking advantage of the ring even and odd resonances, it is able to operate in concurrent dual quasi-periodic mode and injection-locked regime. In the second case, it behaves as a dual frequency zero-IF mixer. The stability properties are analyzed with a reduced-order determinant function that overcomes the problem of limited observability due to a high isolation between different circuit sections. Various procedures, enabling the calculation of the conversion gain, injection-locking bandwidths and phase-noise spectral density, have been applied to a dual mixer at the frequencies 2.3 GHz and 4.1 GHz.