Analog Devices,inc.

Hittite Microwave Corporation

John Poelker

Ekrem Oran

Cemin Zhang

John A Chiesa

Christopher O'Neill

Michael Koechlin

Christoph M Steinbrecher

Byungmoo Min

Santosh Anil Kudtarkar

Faith Kocer

Fatih Kocer

Po-Hao Yeh

Apparatus and methods for tunable filtering are provided. In certain embodiments, a tunable filter is implemented using one or more controllable capacitors formed on a semiconductor die and using one or more shielded integrated inductors formed on a secondary circuit board that attaches to a carrier circuit board. Additionally, the shielded integrated inductors are formed from patterned metallization layers of the secondary circuit board, and shielding is provided on the secondary circuit board and/or the carrier circuit board to shield the inductors from the semiconductor die and/or other components.

Apparatus and methods for tunable filtering

A die is packaged by flip-chip mounting the die with the active side facing a low loss substrate. A ground plane is coupled to the active side of the die by vias through the low loss substrate. The ground plane is positioned to concentrate high frequency electromagnetic fields in the low loss substrate. A tuning height can be adjusted to tune the center frequency of a circuit in the die.

Circuit with reduced noise and controlled frequency

A voltage controlled oscillator including an RF output terminal and a DC control terminal, an active circuit, and a resonant circuit interconnected with the active circuit and including a plurality of series resonators each having an electrically variable capacitance and fixed inductor; the active circuit includes at least one transistor having an operating current density which is approximately 35% or less of the peak foperating current density and/or the active circuit includes a multi-transistor bank disposed in at least two separate sections, each pair of sections spaced apart to provide improved thermal uniformity among the transistors without substantially increasing parasitic impedance among them for providing an improved lower phase noise output at said RF output terminal.

Voltage controlled oscillator

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Andover, MA, United States of America

John Poelker