2026-04-06 Latest Published
By Abdelmounim Sellidj
Tarek Djerafi
Said Gaoua
Mustapha Yagoub
Progress In Electromagnetics Research Letters, Vol. 130, 23-27, 2026
Abstract
In this work, a Substrate-Integrated Waveguide (SIW) cavity-based positive-feedback oscillator integrated with a slot antenna on a single substrate was designed. The proposed design incorporates a radiating element, an oscillator tank, and a coupling structure within the same cavity, thereby eliminating external interconnections and significantly enhancing overall efficiency. By employing the TE210 mode instead of the TE110, the design exploits a field node to minimize the parasitic loading effects of the oscillator coupling probe on the antenna radiation. This approach simultaneously enhances the cavity's quality factor Q and preserves the spectral purity of the integrated SIW antenna-oscillator, all this without affecting the antenna radiation. The SIW cavity achieves a measured quality factor (Q) of 250, ensuring high spectral selectivity at the 10 GHz resonant frequency. The oscillator exhibits low phase noise of -131 dBc/Hz at a 1 MHz offset, along with exceptional suppression of harmonics, including the total suppression of the third harmonic, while the slot antenna achieves a gain of 6 dBi. This fully integrated architecture delivers performance equivalent to discrete implementations while offering a compact footprint and eliminating insertion losses between the antenna and the oscillator.
