Telefonaktiebolaget Lm Ericsson (publ)

Optis Cellular Technology, LLC

Lars Aspemyr

Harald Jacobsson

The present invention relates to an oscillating circuit arrangement having a resonating arrangement with a first resonance frequency (coo) comprising a voltage controlled oscillator arrangement. It further comprises a tunable filter arrangement connected to the source node of said voltage controlled oscillator (VCO) arrangement. Said filter arrangement particularly comprises an equivalent current source resonating at a second resonance frequency c&#x3b8;f, the second resonance frequency being a multiple n, n=1 or 2 of said first resonance frequency (&#x3b1;&#x3e;o), n being equal to the minimum number of switch transistors required for oscillation of said VCO arrangement. The filter arrangement particularly comprises an inductor connected in parallel with a capacitor, said capacitor being adapted to be tunable such that the phase noise of the resonating arrangement can be minimized through tuning of the filter arrangement.

Automatically tuned tail filter

The present invention relates to an oscillator circuit having a resonant element, an active element, a feedback loop, and an additional loop comprising a phase shifting element.

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Kungsbacka, Sweden

Lars Aspemyr