Abstract
A concurrent dual-band self-oscillating mixer (SOM), based on a ring-shaped stepped-impedance resonator, is proposed and analyzed in detail. Taking advantage of the ring even and odd resonances, the circuit can operate in concurrent dual quasi-periodic mode and injection-locked mode. In the second case, it behaves as a dual-band zero-intermediate-frequency (IF) mixer. Initially, an analytical study of the SOM behavior in the two modes is presented. Then a variety of accurate numerical methods are used for an in-depth investigation of the main aspects of its performance, including stability, conversion gain, linearity, and phase noise. The recently proposed contour-intersection technique and the outer-tier perturbation analysis are suitably adapted to the SOM case. A method is also presented to distinguish the parameter intervals leading to heterodyne and to zero-IF operation at both the lower and upper frequency bands. In the zero-IF SOM, the possible instantaneous unlocking in the presence of modulated input signals is investigated and avoided. The methods have been applied to a dual mixer at the frequencies 2.4 and 4.1 GHz.
Highlights
The recent works [1]-[3] present a novel concept to obtain zero-IF frequency conversion using an injection-locked oscillator, suitably designed and biased to enhance its mixing capabilities
In the concurrent dualfrequency zero-IF self-oscillating mixer (SOM), each oscillation gets locked to its corresponding RF signal [4], so the circuit behaves as a concurrent dual-frequency injection-locked oscillator
A major challenge in the design of concurrent dual-frequency oscillators is the robustness of this concurrent operation mode [8], which mathematically coexists with two periodic solutions, at ω1 and ω2, respectively, and with the DC solution
Summary
The recent works [1]-[3] present a novel concept to obtain zero-IF frequency conversion using an injection-locked oscillator, suitably designed and biased to enhance its mixing capabilities. Considering the increasing demand of multiband wireless systems, the work [4] proposed a concurrent dual-band zero-IF SOM, which extends the compact frequency conversion to simultaneous operation in two frequency bands This requires a concurrent dualfrequency oscillator at two incommensurable fundamental frequencies ω1 and ω2 [5]-[7], which corresponds to a doubly autonomous quasi–periodic solution. An analytical investigation of the SOM behavior in the two modes is presented It provides insight into the conversion gain, linearity, and oscillation extinction, in the heterodyne case, and the injection-locked operation and mechanisms for the amplitude and frequency demodulation, in the zero IF case.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
